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Sample records for aureus mscramm sdrc

  1. Allosteric Regulation of Fibronectin/α5β1 Interaction by Fibronectin-Binding MSCRAMMs

    PubMed Central

    Liang, Xiaowen; Garcia, Brandon L.; Visai, Livia; Prabhakaran, Sabitha; Meenan, Nicola A. G.; Potts, Jennifer R.; Humphries, Martin J.; Höök, Magnus

    2016-01-01

    Adherence of microbes to host tissues is a hallmark of infectious disease and is often mediated by a class of adhesins termed MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules). Numerous pathogens express MSCRAMMs that specifically bind the heterodimeric human glycoprotein fibronectin (Fn). In addition to roles in adhesion, Fn-binding MSCRAMMs exploit physiological Fn functions. For example, several pathogens can invade host cells by a mechanism whereby MSCRAMM-bound Fn bridges interaction with α5β1 integrin. Here, we investigate two Fn-binding MSCRAMMs, FnBPA (Staphylococcus aureus) and BBK32 (Borrelia burgdorferi) to probe structure-activity relationships of MSCRAMM-induced Fn/α5β1integrin activation. Circular dichroism, fluorescence resonance energy transfer, and dynamic light scattering techniques uncover a conformational rearrangement of Fn involving domains distant from the MSCRAMM binding site. Surface plasmon resonance experiments demonstrate a significant enhancement of Fn/α5β1 integrin affinity in the presence of FnBPA or BBK32. Detailed kinetic analysis of these interactions reveal that this change in affinity can be attributed solely to an increase in the initial Fn/α5β1 on-rate and that this rate-enhancement is dependent on high-affinity Fn-binding by MSCRAMMs. These data implicate MSCRAMM-induced perturbation of specific intramolecular contacts within the Fn heterodimer resulting in activation by exposing previously cryptic α5β1 interaction motifs. By correlating structural changes in Fn to a direct measurement of increased Fn/α5β1 affinity, this work significantly advances our understanding of the structural basis for the modulation of integrin function by Fn-binding MSCRAMMs. PMID:27434228

  2. 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.

  3. Collagen-binding Microbial Surface Components Recognizing Adhesive Matrix Molecule (MSCRAMM) of Gram-positive Bacteria Inhibit Complement Activation via the Classical Pathway*

    PubMed Central

    Kang, Mingsong; Ko, Ya-Ping; Liang, Xiaowen; Ross, Caná L.; Liu, Qing; Murray, Barbara E.; Höök, Magnus

    2013-01-01

    Members of a family of collagen-binding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) from Gram-positive bacteria are established virulence factors in several infectious diseases models. Here, we report that these adhesins also can bind C1q and act as inhibitors of the classical complement pathway. Molecular analyses of Cna from Staphylococcus aureus suggested that this prototype MSCRAMM bound to the collagenous domain of C1q and interfered with the interactions of C1r with C1q. As a result, C1r2C1s2 was displaced from C1q, and the C1 complex was deactivated. This novel function of the Cna-like MSCRAMMs represents a potential immune evasion strategy that could be used by numerous Gram-positive pathogens. PMID:23720782

  4. Pneumococcal MSCRAMM targeting of the extracellular matrix

    PubMed Central

    Paterson, Gavin K.; Orihuela, Carlos J.

    2010-01-01

    The attachment of bacteria to host cells and tissues and their subsequent invasion and dissemination are key processes during disease pathogenesis. In this issue of Molecular Microbiology, Jensch and co-workers provide further molecular insight into these events during infection with the Gram-positive bacterium Streptococcus pneumoniae. Their characterization of PavB, a bacterial surface protein with orthologues in other streptococci, shows it to bind the extracellar matrix components fibronection and plasminogen by virtue of repetitive sequences designated Streptococcal Surface Repeats (SSURE). In mice, a pavB mutant showed reduced nasopharyngeal colonisation and was attenuated in a lung infection model. As discussed here in the context of the pneumococcus, the study of PavB highlights the central role during microbal pathogenesis of targetting the extracellular matrix by so-called MSCRAMMs (microbial surface components recognizing adhesive matrix molecules). PMID:20444102

  5. Role of Staphylococcus aureus surface adhesins in orthopaedic device infections: are results model-dependent?

    PubMed

    Darouiche, R O; Landon, G C; Patti, J M; Nguyen, L L; Fernau, R C; McDevitt, D; Greene, C; Foster, T; Klima, M

    1997-01-01

    Bacterial colonisation of prosthetic material can lead to clinical infection or implant failure, or both, often requiring removal of the device. Adherence of Staphylococcus aureus to bioprosthetic materials is mediated by adhesins belonging to the MSCRAMM (microbial surface components recognising adhesive matrix molecules) family of microbial cell surface proteins. The objective of this study was to compare the virulence of a mutant strain of S. aureus Newman that possesses all three fibrinogen-, fibronectin- and collagen-binding MSCRAMMs (MSCRAMM-positive strain) with that of a mutant strain that lacks all three types of MSCRAMMs (MSCRAMM-negative strain) in a rabbit model of orthopaedic device-related infection. After a hole was drilled into the knee joint of each animal, a group of 10 rabbits was inoculated with the MSCRAMM-positive strain and another group of 10 rabbits received the MSCRAMM-negative strain. A stainless steel screw was then placed into the drilled hole. Two weeks later, the rabbits were killed and serum samples, bone tissue and implants were harvested for bacteriological and histopathological evaluation. No significant difference in infection rates was demonstrated between the two groups. The ability to delineate the role of S. aureus surface adhesins in causing orthopaedic device-related infection could be model-dependent.

  6. A Novel Fibronectin Binding Motif in MSCRAMMs Targets F3 Modules

    PubMed Central

    Prabhakaran, Sabitha; Liang, Xiaowen; Skare, Jonathan T.; Potts, Jennifer R.; Höök, Magnus

    2009-01-01

    Background BBK32 is a surface expressed lipoprotein and fibronectin (Fn)-binding microbial surface component recognizing adhesive matrix molecule (MSCRAMM) of Borrelia burgdorferi, the causative agent of Lyme disease. Previous studies from our group showed that BBK32 is a virulence factor in experimental Lyme disease and located the Fn-binding region to residues 21–205 of the lipoprotein. Methodology/Principal Findings Studies aimed at identifying interacting sites between BBK32 and Fn revealed an interaction between the MSCRAMM and the Fn F3 modules. Further analysis of this interaction showed that BBK32 can cause the aggregation of human plasma Fn in a similar concentration-dependent manner to that of anastellin, the superfibronectin (sFn) inducing agent. The resulting Fn aggregates are conformationally distinct from plasma Fn as indicated by a change in available thermolysin cleavage sites. Recombinant BBK32 and anastellin affect the structure of Fn matrices formed by cultured fibroblasts and inhibit endothelial cell proliferation similarly. Within BBK32, we have located the sFn-forming activity to a region between residues 160 and 175 which contains two sequence motifs that are also found in anastellin. Synthetic peptides mimicking these motifs induce Fn aggregation, whereas a peptide with a scrambled sequence motif was inactive, suggesting that these motifs represent the sFn-inducing sequence. Conclusions/Significance We conclude that BBK32 induces the formation of Fn aggregates that are indistinguishable from those formed by anastellin. The results of this study provide evidence for how bacteria can target host proteins to manipulate host cell activities. PMID:19404402

  7. The carriage of the serine-aspartate repeat protein-encoding sdr genes among Staphylococcus aureus lineages.

    PubMed

    Liu, Huanle; Lv, Jingnan; Qi, Xiuqin; Ding, Yu; Li, Dan; Hu, Longhua; Wang, Liangxing; Yu, Fangyou

    2015-01-01

    The serine-aspartate repeat proteins (Sdr) are members of a family of surface proteins and contribute to the pathogenicity of Staphylococcus aureus. Among 288 S. aureus isolates including 158 and 130 associated with skin and soft tissue infections and bloodstream infection, respectively; 275 (95.5%) were positive for at least one of three sdr genes tested. The positivity rates for sdrC, sdrD, and sdrE among S. aureus isolates were 87.8% (253/288), 63.9% (184/288), and 68.1% (196/288), respectively. 224 (77.8%) of 288 isolates were concomitantly positive for two or three sdr genes. There was an association between carriage of sdrE and methicillin-resistant S. aureus (MRSA) isolates, while the carriage rates of sdrC and sdrD in MRSA isolates were similar to those in methicillin-sensitive S. aureus (MSSA) isolates. The prevalence of co-existence of sdrC and sdrE among MRSA isolates was significantly higher than that among MSSA isolates (p<0.05). All ST1, ST5, ST7, and ST25 isolates were positive for sdrD. While all ST121 and ST398 isolates were negative for sdrD. All ST59 and ST88 isolates were positive for sdrE. All ST1 isolates were concomitantly positive for sdrC and sdrD. Concomitant carriage of sdrC, sdrD, and sdrE was found among all ST5, 75.0% (9/12) of ST1, 69.2% (9/13) of ST6, 78.6% (11/14) of ST25, and 90.9% (20/22) of ST88 isolates. sdrD was linked to CC5, CC7 and CC88 isolates, especially CC88 isolates. There was a strong association between the presence of sdrE and CC59, CC88, and CC5 isolates. A significant correlation between concomitant carriage of sdrC, sdrD, and sdrE and CC88 isolates was found. sdrC-positive, sdrD-positive and sdrE-negative gene profile was significantly associated with CC7 clone. There was an association between sdrC-positive, sdrD-negative, and sdrE-positive gene profile and CC59 isolates. A correlation between sdrC-positive, sdrD-negative, and sdrE-negative gene profile and CC121 clone was found. More CC59 isolates carried sdr

  8. 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

  9. 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.

  10. Occurrence of genes coding for MSCRAMM and biofilm-associated protein Bap in Staphylococcus spp. isolated from bovine subclinical mastitis and relationship with somatic cell counts.

    PubMed

    Zuniga, Eveline; Melville, Priscilla A; Saidenberg, André B S; Laes, Marco A; Gonsales, Fernanda F; Salaberry, Sandra R S; Gregori, Fabio; Brandão, Paulo E; dos Santos, Franklin G B; Lincopan, Nilton E; Benites, Nilson R

    2015-12-01

    This study aimed to elucidate aspects of the epidemiology of bovine subclinical mastitis through the assessment of genes encoding MSCRAMM (microbial surface components recognizing adhesive matrix molecules - a group of adhesins) and protein Bap (implicated in biofilm formation), in coagulase-positive (CPS) and coagulase-negative (CNS) Staphylococcus isolated from subclinical mastitis. Milk samples were collected for microbiological exams, somatic cell count (SCC) and a survey of the genes coding for MSCRAMM (cna, eno, ebpS, fnbA, fnbB and fib) and biofilm-associated protein Bap (bap) in 106 Staphylococcus spp. isolates using PCR. The frequencies of occurrence of eno (82.1%), fnbA (72.6%), fib (71.7%) and bap (56.6%) were higher (P < 0.0001) compared with the other assessed genes (cna, ebpS and fnbB). The higher frequency of occurrence (P < 0.005) of the bap gene in CNS compared with CPS suggests that in these species biofilm formation is an important mechanism for the persistence of the infection. The medians of the SCCs in the samples where eno, fnbA, fib and bap genes were detected were higher compared with Staphylococcus without the assessed genes (P < 0.05) and negative samples (P < 0.01), which indicated that the presence of these MSCRAMM may be related to a higher intensity of the inflammatory process.

  11. Protective activity of the CnaBE3 domain conserved among Staphylococcus aureus Sdr proteins.

    PubMed

    Becherelli, Marco; Prachi, Prachi; Viciani, Elisa; Biagini, Massimiliano; Fiaschi, Luigi; Chiarot, Emiliano; Nosari, Sarah; Brettoni, Cecilia; Marchi, Sara; Biancucci, Marco; Fontana, Maria Rita; Montagnani, Francesca; Bagnoli, Fabio; Barocchi, Michèle A; Manetti, Andrea G O

    2013-01-01

    Staphylococcus aureus is an opportunistic pathogen, commensal of the human skin and nares, but also responsible for invasive nosocomial as well as community acquired infections. Staphylococcus aureus adheres to the host tissues by means of surface adhesins, such as SdrC, SdrD, and SdrE proteins. The Sdr family of proteins together with a functional A domain, contain respectively two, three or five repeated sequences called B motifs which comprise the CnaB domains. SdrD and SdrE proteins were reported to be protective in animal models against invasive diseases or lethal challenge with human clinical S. aureus isolates. In this study we identified a 126 amino acid sequence containing a CnaB domain, conserved among the three Sdr proteins. The three fragments defined here as CnaBC2, D5 and E3 domains even though belonging to phylogenetically distinct strains, displayed high sequence similarity. Based on the sequence conservation data, we selected the CnaBE3 domain for further analysis and characterization. Polyclonal antibodies raised against the recombinant CnaBE3 domain recognized SdrE, SdrC and SdrD proteins of different S. aureus lineages. Moreover, we demonstrated that the CnaBE3 domain was expressed in vivo during S. aureus infections, and that immunization of this domain alone significantly reduces the bacterial load in mice challenged with S. aureus. Furthermore, we show that the reduction of bacteria by CnaBE3 vaccination is due to functional antibodies. Finally, we demonstrated that the region of the SdrE protein containing the CnaBE3 domain was resistant to trypsin digestion, a characteristic often associated with the presence of an isopeptide bond.

  12. X-ray crystal structures of Staphylococcus aureus collagen adhesin and sortases

    NASA Astrophysics Data System (ADS)

    Zong, Yinong

    For many gram-positive bacteria, adhesion to host tissues is the first critical step in developing an infection. The adhesion is mediated by a superfamily of bacterial surface proteins, called MSCRAMM (microbial surface components recognizing adhesive matrix molecules), which in most cases are covalently attached to the cell wall peptidoglycan. Collagen adhesin (CNA) from Staphylococcus aureus, one of the MSCRAMMs, is responsible for bacterial binding to collagen molecules. CNA and other MSCRAMMs are anchored to the cell wall by a transpeptidase, sortase. The knowledge about how bacterial surface proteins adhere to host molecules and how they are sorted onto the cell wall is crucial for the design of novel antibiotics against bacterial infections. The crystal structures of CNA31--344 (residue 31 to 334), a truncation of CNA's collagen binding region, and CNA31--344 in complex with a collagen peptide were determined. CNA31--344 contains two domains, and between them is a big hole formed by a loop connecting the two domains. In the structure of CNA31--344-collagen complex, the collagen peptide is locked in the hole formed by the two domains of CNA 31--344. We reason that the two domains of CNA31--344 are open in the physiological condition, and close up when binding to collagen. This binding mechanism may be common for other bacterial collagen adhesins. There are two known sortases in Staphylococcus aureus. Sortase A is responsible for anchoring most MSCRAMMs that have a LPXTG (X represents any amino acid) sorting motif and sortase B for a bacterial ion acquisition protein. The crystal structures of both sortases indicate that they share a common catalytic mechanism. Unlike typical cysteine transpeptidases, sortases may use a novel Cys-Arg catalytic dyad instead of a Cys-His pair. All other sortases found in gram-positive bacteria may have similar active site architecture and employ the same catalytic dyad because the critical residues are all conserved among them

  13. Serine-Aspartate Repeat Protein D Increases Staphylococcus aureus Virulence and Survival in Blood

    PubMed Central

    Uchiyama, Satoshi; Valderrama, J. Andrés; Ajayi, Clement; Sollid, Johanna U. E.; van Sorge, Nina M.; Nizet, Victor; van Strijp, Jos A. G.

    2016-01-01

    ABSTRACT Staphylococcus aureus expresses a panel of cell wall-anchored adhesins, including proteins belonging to the microbial surface components recognizing adhesive matrix molecule (MSCRAMM) family, exemplified by the serine-aspartate repeat protein D (SdrD), which serve key roles in colonization and infection. Deletion of sdrD from S. aureus subsp. aureus strain NCTC8325-4 attenuated bacterial survival in human whole blood ex vivo, which was associated with increased killing by human neutrophils. Remarkably, SdrD was able to inhibit innate immune-mediated bacterial killing independently of other S. aureus proteins, since addition of recombinant SdrD protein and heterologous expression of SdrD in Lactococcus lactis promoted bacterial survival in human blood. SdrD contributes to bacterial virulence in vivo, since fewer S. aureus subsp. aureus NCTC8325-4 ΔsdrD bacteria than bacteria of the parent strain were recovered from blood and several organs using a murine intravenous infection model. Collectively, our findings reveal a new property of SdrD as an important key contributor to S. aureus survival and the ability to escape the innate immune system in blood. PMID:27795358

  14. Distribution of the serine-aspartate repeat protein-encoding sdr genes among nasal-carriage and invasive Staphylococcus aureus strains.

    PubMed

    Sabat, Artur; Melles, Damian C; Martirosian, Gayane; Grundmann, Hajo; van Belkum, Alex; Hryniewicz, Waleria

    2006-03-01

    The sdr locus was found in all 497 investigated Staphylococcus aureus strains, although in 29 strains it contained only the sdrC gene (sdrD negative, sdrE negative). The sdrC-positive, sdrD-negative, sdrE-negative gene profile was exclusive to methicillin-sensitive S. aureus (MSSA) strains (Fisher's exact test; P = 0.0005) and was not found in the strains collected from bone infections (P = 0.0019). We also found a strong association between the presence of the sdrD gene and methicillin-resistant S. aureus strains (P < 0.0001). Our findings suggest that MSSA strains with the newly uncovered sdrC-positive, sdrD-negative, sdrE-negative gene profile have a substantially decreased potential to establish bone infection.

  15. Comparison of virulence factors and biofilm formation among Staphylococcus aureus strains isolated from human and bovine infections.

    PubMed

    Khoramian, Babak; Jabalameli, Fereshteh; Niasari-Naslaji, Amir; Taherikalani, Morovat; Emaneini, Mohammad

    2015-11-01

    The aim of this study was to find different prevalence of genes involved in the biofilm formation process and to assess the phenotypic and genotypic markers of biofilm formation among Staphylococcus aureus strains isolated from human and bovine infections. In this study, 215 S. aureus strains were collected from human and dairy cow's infections. The biofilm forming capacity of the strains was evaluated using a colorimetric microtiter plate assay. The genes encoding microbial surface components, recognizing adhesive matrix molecules (MSCRAMMs) (ebpS, eno, fib, fnbA, fnbB, cna and bap), and the intracellular adhesion (ica) genes (icaA, and icaD) were targeted by polymerase chain reaction (PCR)-based method. Approximately 70% of the isolates produced biofilm. Among these, 59.3% were producers of weakly adherent biofilms while 34.8% and 5.8% produced moderate and strong biofilms, respectively. The most prevalent gene was icaD found in 88.4% of the isolates, followed by icaA, fib and eno found in 87.9%, 75.8% and 75.3% of the isolates, respectively. The bap gene was not detected in any of the isolates. The prevalence of ebpS and fnbA genes among bovine isolates were significantly higher than those in human isolates, whilst the prevalence of cna gene was significantly higher in the human isolates. In this study, a high prevalence of biofilm production was found among S. aureus strains isolated from human and bovine infections. Most biofilm producing isolates were positive for MSCRAMM, icaA, and icaD genes.

  16. Crystal Structure of an Invasivity-Associated Domain of SdrE in S. aureus

    PubMed Central

    Zhang, Hongpeng; Yang, Wei; Zhu, Zhongliang; Chen, Ke; Bai, Lei; Wei, Jie; Huang, Ailong; Wang, Deqiang

    2017-01-01

    The surface protein SdrE, a microbial surface components recognizing adhesive matrix molecule (MSCRAMM) family protein expressed on the surface of Staphylococcus aureus (S. aureus), can recognize human complement regulator Factor H and C4BP, thus making it a potentially promising vaccine candidate. In this study, SdrE278-591 was found to directly affect S. aureus host cell invasion. Additionally, the crystal structure of SdrE278-591 at a resolution of 1.25 Å was established, with the three-dimensional structure revealing N2-N3 domains which fold in a manner similar to an IgG fold. Furthermore, a putative ligand binding site located at a conserved charged groove formed by the interface between N2 and N3 domains was identified, with β2 suspected to occupy the ligand recognizing site and undergo a structural rearrangement to allow ligand binding. Overall, these findings have further contributed to the understanding of SdrE as a key factor for S. aureus invasivity and will enable a better understanding of bacterial infection processes. PMID:28125581

  17. Staphylococcus aureus fibronectin binding proteins A and B possess a second fibronectin binding region that may have biological relevance to bone tissues.

    PubMed

    Williams, R J; Henderson, B; Nair, S P

    2002-05-01

    Staphylococcus aureus is a major human pathogen that has a propensity for targeting to bone tissues and thereby causing bone disease. A plausible hypothesis is that S. aureus targets to bone using the MSCRAMM family of surface proteins possessed by this organism. Two such proteins that have recently been shown to be important in bone infections are the S. aureus fibronectin binding proteins (FnBP) A and B. To identify fibronectin-binding domains from S. aureus that have biological relevance to bone, a phage display library of S. aureus genomic DNA was constructed and panned sequentially against immobilized fibronectin and cultured osteoblasts. Using this system, phage displaying a second fibronectin-binding region within the N-terminal part of FnBPA and FnBPB, which is distinct from the primary fibronectin-binding domain located within the D repeat region of these proteins, was isolated. Phage displaying this second region bound to both immobilized fibronectin and to osteoblasts and/or the extracellular matrix synthesized by these cells, thereby suggesting a biological relevance for these regions in S. aureus binding to bone tissues. Analysis of these binding regions for their ability to bind to other extracellular matrix proteins revealed a preference for fibronectin, with slight binding to fibrinogen and no binding to collagen or laminin.

  18. Identification and phenotypic characterization of a second collagen adhesin, Scm, and genome-based identification and analysis of 13 other predicted MSCRAMMs, including four distinct pilus loci, in Enterococcus faecium

    PubMed Central

    Sillanpää, Jouko; Nallapareddy, Sreedhar R.; Prakash, Vittal P.; Qin, Xiang; Hook, Magnus; Weinstock, George M.; Murray, Barbara E.

    2009-01-01

    SUMMARY Attention has recently been drawn to Enterococcus faecium because of an increasing number of nosocomial infections caused by this species and its resistance to multiple antibacterial agents. However, relatively little is known about pathogenic determinants of this organism. We have previously identified a cell wall anchored collagen adhesin, Acm, produced by some isolates of E. faecium, and a secreted antigen, SagA, exhibiting broad spectrum binding to extracellular matrix proteins. Here, we analyzed the draft genome of strain TX0016 for potential MSCRAMMs (microbial surface component recognizing adhesive matrix molecules). Genome-based bioinformatics identified 22 predicted cell wall anchored E. faeciumsurface proteins (Fms) of which 15 (including Acm) have typical characteristics of MSCRAMMs including predicted folding into a modular architecture with multiple immunoglobulin-like domains. Functional characterization of one (Fms10, redesignated Scm for second collagen adhesin of E. faeciu m) revealed that recombinant Scm65 (A- and B-domains) and Scm36 (A-domain) bound efficiently to collagen type V in a concentration dependent manner, bound considerably less to collagen type I and fibrinogen, and differed from Acm in their binding specificities to collagen types IV and V. Results from far-UV circular dichroism of recombinant Scm36 and of Acm37 indicated that these proteins are rich in β-sheets, supporting our folding predictions. Whole-cell ELISA and FACS analyses unambiguously demonstrated surface expression of Scm in most E. faecium isolates. Strikingly, 11 of the 15 predicted MSCRAMMs clustered in four loci, each with a class C sortase gene; 9 of these showed similarity to Enterococcus faecalis Ebp pilus subunits and also contained motifs essential for pilus assembly. Antibodies against one of the predicted major pilus proteins, Fms9 (redesignated as EbpCfm), detected a “ladder” pattern of high-molecular weight protein bands in a Western blot

  19. Identification and phenotypic characterization of a second collagen adhesin, Scm, and genome-based identification and analysis of 13 other predicted MSCRAMMs, including four distinct pilus loci, in Enterococcus faecium.

    PubMed

    Sillanpää, Jouko; Nallapareddy, Sreedhar R; Prakash, Vittal P; Qin, Xiang; Höök, Magnus; Weinstock, George M; Murray, Barbara E

    2008-10-01

    Attention has recently been drawn to Enterococcus faecium because of an increasing number of nosocomial infections caused by this species and its resistance to multiple antibacterial agents. However, relatively little is known about the pathogenic determinants of this organism. We have previously identified a cell-wall-anchored collagen adhesin, Acm, produced by some isolates of E. faecium, and a secreted antigen, SagA, exhibiting broad-spectrum binding to extracellular matrix proteins. Here, we analysed the draft genome of strain TX0016 for potential microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Genome-based bioinformatics identified 22 predicted cell-wall-anchored E. faecium surface proteins (Fms), of which 15 (including Acm) had characteristics typical of MSCRAMMs, including predicted folding into a modular architecture with multiple immunoglobulin-like domains. Functional characterization of one [Fms10; redesignated second collagen adhesin of E. faecium (Scm)] revealed that recombinant Scm(65) (A- and B-domains) and Scm(36) (A-domain) bound to collagen type V efficiently in a concentration-dependent manner, bound considerably less to collagen type I and fibrinogen, and differed from Acm in their binding specificities to collagen types IV and V. Results from far-UV circular dichroism measurements of recombinant Scm(36) and of Acm(37) indicated that these proteins were rich in beta-sheets, supporting our folding predictions. Whole-cell ELISA and FACS analyses unambiguously demonstrated surface expression of Scm in most E. faecium isolates. Strikingly, 11 of the 15 predicted MSCRAMMs clustered in four loci, each with a class C sortase gene; nine of these showed similarity to Enterococcus faecalis Ebp pilus subunits and also contained motifs essential for pilus assembly. Antibodies against one of the predicted major pilus proteins, Fms9 (redesignated EbpC(fm)), detected a 'ladder' pattern of high-molecular-mass protein bands in a

  20. Antimicrobial susceptibility, virulence determinant carriage and molecular characteristics of Staphylococcus aureus isolates associated with skin and soft tissue infections.

    PubMed

    Yu, Fangyou; Liu, Yunling; Lv, Jinnan; Qi, Xiuqin; Lu, Chaohui; Ding, Yu; Li, Dan; Liu, Huanle; Wang, Liangxing

    2015-01-01

    A better understanding of the antimicrobial susceptibility, carriage of virulence determinants and molecular characteristics of Staphylococcus aureus isolates associated with skin and soft tissue infections (SSTIs) may provide further insights related to clinical outcomes with these infections. From January 2012 to September 2013, a total of 128 non-duplicate S. aureus isolates were recovered from patients with SSTIs. All 128 S. aureus SSTI isolates carried at least five virulence genes tested. Virulence genes detected among at least 70% of all tested isolates included hld (100%), hla (95.3%), icaA (96.9%), clf (99.2%), sdrC (79.7%), sdrD (70.3%), and sdrE (72.7%). The prevalence of MRSA isolates with 10 virulence genes tested (54.4%, 31/56) was significantly higher than that among MSSA isolates (35.2%, 25/71) (p<0.05). The positive rates of seb, sen, sem, sdrE and pvl among MRSA isolates were significantly higher than among MSSA isolates (p<0.05). ST7 and ST630 accounting for 10.9% were found to be the predominant STs. The most prevalent spa type was t091 (8.6%). MRSA-ST59-SCCmec IV was the most common clone (12.3%) among MRSA isolates whereas among MSSA isolates the dominant clone was MSSA-ST7 (15.5%). Six main clonal complexes (CCs) were found, including CC5 (52.3%), CC7 (11.7%), CC59 (8.6%), CC88 (6.3%), CC398 (4.7%), and CC121 (3.1%). A higher carriage of seb and sec was found among CC59 isolates. In comparison to CC5 and CC7 isolates, those with the highest carriage rates (>80.0%) of sdrC and sdrD, CC59 isolates had lower prevalence of these two virulence genes. All CC59 isolates were susceptible to gentamicin and trimethoprim/sulfamethoxazole, while CC5 and CC7 isolates had resistance rates to these two antimicrobials of 25.4% and 20.9%, and 40.0% and 40.0%, respectively. The resistance rates for tetracycline, clindamycin, and erythromycin among CC5 isolates were lower than among CC7 and CC59 isolates. In conclusion, the molecular typing of S. aureus SSTI

  1. The interaction between Staphylococcus aureus SdrD and desmoglein 1 is important for adhesion to host cells

    PubMed Central

    Askarian, Fatemeh; Ajayi, Clement; Hanssen, Anne-Merethe; van Sorge, Nina M.; Pettersen, Ingvild; Diep, Dzung B.; Sollid, Johanna U. E.; Johannessen, Mona

    2016-01-01

    Staphylococcus aureus is known as a frequent colonizer of the skin and mucosa. Among bacterial factors involved in colonization are adhesins such as the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Serine aspartate repeat containing protein D (SdrD) is involved in adhesion to human squamous cells isolated from the nose. Here, we identify Desmoglein 1 (Dsg1) as a novel interaction partner for SdrD. Genetic deletion of sdrD in S. aureus NCTC8325-4 through allelic replacement resulted in decreased bacterial adherence to Dsg1- expressing HaCaT cells in vitro. Complementary gain-of-function was demonstrated by heterologous expression of SdrD in Lactococcus lactis, which increased adherence to HaCaT cells. Also ectopic expression of Dsg1 in HEK293 cells resulted in increased adherence of S. aureus NCTC8325-4 in vitro. Increased adherence of NCTC8325-4, compared to NCTC8325-4ΔsdrD, to the recombinant immobilized Dsg1 demonstrated direct interaction between SdrD and Dsg1. Specificity of SdrD interaction with Dsg1 was further verified using flow cytometry and confirmed binding of recombinant SdrD to HaCaT cells expressing Dsg1 on their surface. These data demonstrate that Dsg1 is a host ligand for SdrD. PMID:26924733

  2. Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus

    PubMed Central

    Blomqvist, Susanne; Leonhardt, Åsa; Arirachakaran, Pratanporn; Carlen, Anette; Dahlén, Gunnar

    2015-01-01

    Objective The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers. Materials and methods A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins) and sea, seb, sec, tst, eta, etb, pvl (toxins). MIC90 and MIC50 were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin. Results While the hemolytic phenotype was significantly (p<0.001) more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL) genotype was found in 73–100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIV-positives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillin-resistant S. aureus (MRSA) strains were identified, two from oral infections and one from a Thai HIV patient. Conclusions S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral infections and complaints

  3. Adaptive upregulation of Clumping Factor A (ClfA) by S. aureus in the obese, type 2 diabetic host mediates increased virulence.

    PubMed

    Farnsworth, Christopher W; Schott, Eric M; Jensen, Sarah E; Zukoski, Jacob; Benvie, Abigail M; Refaai, Majed A; Kates, Stephen L; Schwarz, Edward M; Zuscik, Michael J; Gill, Steven R; Mooney, Robert A

    2017-03-20

    Obesity and associated type 2 diabetes (T2D) are important risk factors for infection following orthopaedic implant surgery. Staphylococcus aureus, the most common pathogen in bone infections, adapts to multiple environments to survive and evade host immune responses. Whether adaptation of S. aureus to the unique environment of the obese/T2D host accounts for its increased virulence and persistence in this population is unknown. Thus, we assessed implant-associated osteomyelitis in normal versus high fat-diet obese/T2D mice and found that S. aureus infection was more severe, including increases in bone abscesses relative to non-diabetic controls. S. aureus isolated from bone of obese/T2D mice displayed marked upregulation of four adhesion genes (clfA, clfB, bbp, and sdrC), all with binding affinity for fibrin(ogen). Immunostaining of infected bone revealed increased fibrin deposition surrounding bacterial abscesses in obese/T2D mice. In vitro coagulation assays demonstrated a hypercoagulable state in obese/T2D mice that was comparable to that of diabetic patients. S. aureus with an inactivating mutation in clumping factor A (clfA) showed a reduction in bone infection severity that eliminated the effect of obesity/T2D, while infections in control mice were unchanged. In infected mice that overexpress plasminogen activator inhibitor-1 (PAI-1), S. aureusclfA expression and fibrin-encapsulated abscess communities in bone were also increased, further linking fibrin deposition to S. aureus expression of clfA and infection severity. Together, these results demonstrate an adaptation by S. aureus to obesity/T2D with increased expression of clfA that is associated with the hypercoagulable state of the host and increased virulence of S. aureus.

  4. Antibody Response to Fibronectin-Binding Adhesin FnbpA in Patients with Staphylococcus aureus Infections

    PubMed Central

    Casolini, Fabrizia; Visai, Livia; Joh, Danny; Conaldi, Pier Giulio; Toniolo, Antonio; Höök, Magnus; Speziale, Pietro

    1998-01-01

    We have analyzed antibody reactivity to a fibronectin-binding microbial surface component that recognizes adhesive matrix molecules (MSCRAMM) in blood plasma collected from patients with staphylococcal infections. All patients had elevated levels of anti-MSCRAMM antibodies compared to those of young children who, presumably, had not been exposed to staphylococcal infections. The anti-MSCRAMM antibodies preferentially reacted with the ligand-binding repeat domain of the adhesin. However, these antibodies did not inhibit fibronectin binding. Essentially, all patients had antibodies which specifically recognized the fibronectin-MSCRAMM complex but not the isolated components. Epitopes recognized by these anti-ligand-induced binding sites antibodies were found in each repeat unit of the MSCRAMM. These results demonstrate that staphylococci have bound fibronectin some time during infection and that each repeat unit in the MSCRAMM can engage in ligand binding. Furthermore, our previously proposed model, suggesting that an unordered structure in the MSCRAMM undergoes a conformational change upon ligand binding (K. House-Pompeo, Y. Xu, D. Joh, P. Speziale, and M. Höök, J. Biol. Chem. 271:1379–1384, 1996), is presumably operational in patients during infections. PMID:9784554

  5. SgrA, a nidogen-binding LPXTG surface adhesin implicated in biofilm formation, and EcbA, a collagen binding MSCRAMM, are two novel adhesins of hospital-acquired Enterococcus faecium.

    PubMed

    Hendrickx, Antoni P A; van Luit-Asbroek, Miranda; Schapendonk, Claudia M E; van Wamel, Willem J B; Braat, Johanna C; Wijnands, Lucas M; Bonten, Marc J M; Willems, Rob J L

    2009-11-01

    Hospital-acquired Enterococcus faecium isolates responsible for nosocomial outbreaks and invasive infections are enriched in the orf2351 and orf2430 genes, encoding the SgrA and EcbA LPXTG-like cell wall-anchored proteins, respectively. These two surface proteins were characterized to gain insight into their function, since they may have favored the rapid emergence of this nosocomial pathogen. We are the first to identify a surface adhesin among bacteria (SgrA) that binds to the extracellular matrix molecules nidogen 1 and nidogen 2, which are constituents of the basal lamina. EcbA is a novel E. faecium MSCRAMM (microbial surface component recognizing adhesive matrix molecules) that binds to collagen type V. In addition, both SgrA and EcbA bound to fibrinogen; however, SgrA targeted the alpha and beta chains, whereas EcbA bound to the gamma chain of fibrinogen. An E. faecium sgrA insertion mutant displayed reduced binding to both nidogens and fibrinogen. SgrA did not mediate binding of E. faecium cells to biotic materials, such as human intestinal epithelial cells, human bladder cells, and kidney cells, while this LPXTG surface adhesin is implicated in E. faecium biofilm formation. The acm and scm genes, encoding two other E. faecium MSCRAMMs, were expressed at the mRNA level together with sgrA during all phases of growth, whereas ecbA was expressed only in exponential and late exponential phase, suggesting orchestrated expression of these adhesins. Expression of these surface proteins, which bind to extracellular matrix proteins and are involved in biofilm formation (SgrA), may contribute to the pathogenesis of hospital-acquired E. faecium infections.

  6. 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.

  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. Clinical isolates of Enterococcus faecium exhibit strain-specific collagen binding mediated by Acm, a new member of the MSCRAMM family.

    PubMed

    Nallapareddy, Sreedhar R; Weinstock, George M; Murray, Barbara E

    2003-03-01

    A collagen-binding adhesin of Enterococcus faecium, Acm, was identified. Acm shows 62% similarity to the Staphylococcus aureus collagen adhesin Cna over the entire protein and is more similar to Cna (60% and 75% similarity with Cna A and B domains respectively) than to the Enterococcus faecalis collagen-binding adhesin, Ace, which shares homology with Acm only in the A domain. Despite the detection of acm in 32 out of 32 E. faecium isolates, only 11 of these (all clinical isolates, including four vancomycin-resistant endocarditis isolates and seven other isolates) exhibited binding to collagen type I (CI). Although acm from three CI-binding vancomycin-resistant E. faecium clinical isolates showed 100% identity, analysis of acm genes and their promoter regions from six non-CI-binding strains identified deletions or mutations that introduced stop codons and/or IS elements within the gene or the promoter region in five out of six strains, suggesting that the presence of an intact functional acm gene is necessary for binding of E. faecium strains to CI. Recombinant Acm A domain showed specific and concentration-dependent binding to collagen, and this protein competed with E. faecium binding to immobilized CI. Consistent with the adherence phenotype and sequence data, probing with Acm-specific IgGs purified from anti-recombinant Acm A polyclonal rabbit serum confirmed the surface expression of Acm in three out of three collagen-binding clinical isolates of E. faecium tested, but in none of the strains with a non-functional pseudo acm gene. Introduction of a functional acm gene into two non-CI-binding natural acm mutant strains conferred a CI-binding phenotype, further confirming that native Acm is sufficient for the binding of E. faecium to CI. These results demonstrate that acm, which encodes a potential virulence factor, is functional only in certain infection-derived clinical isolates of E. faecium, and suggest that Acm is the primary adhesin responsible for the

  9. Characterization of the effect of serum and chelating agents on Staphylococcus aureus biofilm formation; chelating agents augment biofilm formation through clumping factor B

    NASA Astrophysics Data System (ADS)

    Abraham, Nabil Mathew

    Staphylococcus aureus is the causative agent of a diverse array of acute and chronic infections, and some these infections, including infective endocarditis, joint infections, and medical device-associated bloodstream infections, depend upon its capacity to form tenacious biofilms on surfaces. Inserted medical devices such as intravenous catheters, pacemakers, and artificial heart valves save lives, but unfortunately, they can also serve as a substrate on which S. aureus can form a biofilm, attributing S. aureus as a leading cause of medical device-related infections. The major aim of this work was take compounds to which S. aureus would be exposed during infection and to investigate their effects on its capacity to form a biofilm. More specifically, the project investigated the effects of serum, and thereafter of catheter lock solutions on biofilm formation by S. aureus. Pre-coating polystyrene with serum is frequently used as a method to augment biofilm formation. The effect of pre-coating with serum is due to the deposition of extracellular matrix components onto the polystyrene, which are then recognized by MSCRAMMs. We therefore hypothesized that the major component of blood, serum, would induce biofilm formation. Surprisingly, serum actually inhibited biofilm formation. The inhibitory activity was due to a small molecular weight, heat-stable, non-proteinaceous component/s of serum. Serum-mediated inhibition of biofilm formation may represent a previously uncharacterized aspect of host innate immunity that targets the expression of a key bacterial virulence factor: the ability to establish a resistant biofilm. Metal ion chelators like sodium citrate are frequently chosen to lock intravenous catheters because they are regarded as potent inhibitors of bacterial biofilm formation and viability. We found that, while chelating compounds abolished biofilm formation in most strains of S. aureus, they actually augmented the phenotype in a subset of strains. We

  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. Genotypic characterization of methicillin-resistant Staphylococcus aureus strains isolated from the anterior nares and catheter of ambulatory hemodialysis patients in Mexico.

    PubMed

    Paniagua-Contreras, Gloria; Monroy-Pérez, Eric; Gutiérrez-Lucas, Raúl; Sainz-Espuñes, Teresita; Bustos-Martínez, Jaime; Vaca, Sergio

    2014-07-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is the causal agent of multiple nosocomial infections worldwide, including catheter-associated bacteremia in hemodialysis patients. The purposes of this work were to genetically characterize a group of MRSA isolates from catheter-related infections of ambulatory Mexican hemodialysis patients and to determine whether the strains are the same as those carried by the patients in their anterior nares. Sixteen pairs of MRSA isolates from the catheter (cat) and anterior nares (N) of hemodialysis patients were compared using pulsed-field gel electrophoresis (PFGE), PCR detection of adhesion genes and other virulence markers, and an antibiogram. Three pairs of N/cat MRSA isolates (18.7 %) with identical resistograms also showed the same combination of PCR-detected markers and PFGE pattern; one additional pair showed only an identical electrophoretic PFGE pattern. Of the MRSA isolates, 75 % (n = 24) were resistant to ≥ 7 antibiotics, 4 isolates were resistant to 11 antibiotics, and 7 isolates were resistant to the 12 antibiotics tested. The most frequent virulence marker combination found was spa, clfA, clfB, cna, bbp, ebps, map/eap, sdrC, sdrD, sdrE, ica, agr (65.6 %, n = 21). The SCCmec alleles of the 32 MRSA isolates were IV (n = 20), I (n = 7), II (n = 4), and V (n = 1), and no SCCmec type III MRSA was found. The genotypic characterization of the MRSA isolates studied in this work will contribute to a better understanding of the virulence gene makeup of catheter-colonizing S. aureus strains and will help to lower the infection risk in these patients.

  12. 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.

  13. 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.

  14. 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.

  15. Implementation of a novel in vitro model of infection of reconstituted human epithelium for expression of virulence genes in methicillin-resistant Staphylococcus aureus strains isolated from catheter-related infections in Mexico

    PubMed Central

    2014-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) are clinically relevant pathogens that cause severe catheter-related nosocomial infections driven by several virulence factors. Methods We implemented a novel model of infection in vitro of reconstituted human epithelium (RHE) to analyze the expression patterns of virulence genes in 21 MRSA strains isolated from catheter-related infections in Mexican patients undergoing haemodialysis. We also determined the phenotypic and genotypic co-occurrence of antibiotic- and disinfectant-resistance traits in the S. aureus strains, which were also analysed by pulsed-field-gel electrophoresis (PFGE). Results In this study, MRSA strains isolated from haemodialysis catheter-related infections expressed virulence markers that mediate adhesion to, and invasion of, RHE. The most frequent pattern of expression (present in 47.6% of the strains) was as follows: fnbA, fnbB, spa, clfA, clfB, cna, bbp, ebps, eap, sdrC, sdrD, sdrE, efb, icaA, and agr. Seventy-one percent of the strains harboured the antibiotic- and disinfectant-resistance genes ermA, ermB, tet(M), tet(K), blaZ, qacA, qacB, and qacC. PFGE of the isolated MRSA revealed three identical strains and two pairs of identical strains. The strains with identical PFGE patterns showed the same phenotypes and genotypes, including the same spa type (t895), suggesting hospital personnel manipulating the haemodialysis equipment could be the source of catheter contamination. Conclusion These findings help define the prevalence of MRSA virulence factors in catheter-related infections. Some of the products of the expressed genes that we detected in this work may serve as potential antigens for inclusion in a vaccine for the prevention of MRSA-catheter-related infections. PMID:24405688

  16. 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

  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. 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.

  20. [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.

  1. Examples of finite element mesh generation using SDRC IDEAS

    NASA Technical Reports Server (NTRS)

    Zapp, John; Volakis, John L.

    1990-01-01

    IDEAS (Integrated Design Engineering Analysis Software) offers a comprehensive package for mechanical design engineers. Due to its multifaceted capabilities, however, it can be manipulated to serve the needs of electrical engineers, also. IDEAS can be used to perform the following tasks: system modeling, system assembly, kinematics, finite element pre/post processing, finite element solution, system dynamics, drafting, test data analysis, and project relational database.

  2. SDRC I-DEAS and RHIC (Relativistic Heavy Ion Collider)

    SciTech Connect

    Goggin, C.M.

    1989-01-01

    In August 1984, Brookhaven National Laboratory submitted a proposal to the Department of Energy (DOE) for the construction of a Relativistic Heavy Ion Collider (RHIC). Since then funding has continued for the detailed design of RHIC. The hardware for RHIC consists of two concentric rings of superconducting magnets in a 2.4 mile circumference with six intersections. Bunches of ions will travel in opposite directions in each of the two rings and eventually collide head on at one of the six intersections. The hardware design involves complicated facilities for liquid helium cryogens, cryostat design, and pipe systems. The greatest challenge however is the ion beam position relative to the geometric center of the rings. There are three hundred and seventy-two dipole magnets that are ten meters long and weigh 4300 Kg (4.5 tons) each. Each dipole must be positioned in the ring to {plus minus} 0.5 mm. In addition, there are four hundred and ninety-two quadrupole magnets that must be positioned to {plus minus} 0.1 mm which is a total position error. This total position error includes all the surveying and part tolerance. To accomplish this task requires detailed planning and design of the cryostats which contain each magnet and the tunnel assembly throughout the 2.4 mile circumference. The IDEAS' software package provides a way to analyze this large scale problem. 11 figs.

  3. Molecular Characteristic and Virulence Gene Profiles of Community-Associated Methicillin-Resistant Staphylococcus aureus Isolates from Pediatric Patients in Shanghai, China

    PubMed Central

    Wang, Xing; Li, Xia; Liu, Wei; Huang, Weichun; Fu, Qihua; Li, Min

    2016-01-01

    Staphylococcus aureus is a globally important human pathogen, especially among children and immunocompromised patients. The emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA) has become a serious public health problem worldwide. The aim of this study was to investigate the prevalence, molecular characteristics and virulence profiles of CA-MRSA infections from pediatric patients in a university hospital in Shanghai, China. A total of 80 CA-MRSA isolates were collected from July 2012 to December 2013 in Shanghai Children's Medical Center and analyzed by multilocus sequence typing, staphylococcus chromosomal cassette mec (SCCmec) typing, and spa typing. The detection of Panton-Valentine Leukocidin (pvl), superantigenic and exfoliative toxins, and adhesin genes was also performed. Overall, 16 distinct sequence types (STs) were identified among the 80 isolates. Among them, ST59 was found to be the most prevalent, followed by ST398 (11.3%, 9/80) and ST88 (8.8%, 7/80). SCCmec types IV and V were observed, at 60 and 40%, respectively. Thirty spa types were identified, spa t437 (23.8%) was the most predominant type. All 80 isolates exhibited carriage of at least four virulence genes. Thirty-four (42.5%, 34/80) isolates harbored ≥10 tested virulence genes. Adhesion genes were present in most of the MRSA isolates, including the following: icaA (100%), clfA (100%), sdrC (95%), and sdrE (63.8%). The prevalence of pvl gene was 20%, and multidrug resistance was observed in 36% of all strains. In addition, ST59-MRSA-IV with t437 accounted for 21.3% of occurrences, making it the most prevalent clone. Isolates that were carriers of toxin genes, and hla (100%) and hlg (87.5%) were the most frequent. In conclusion, simultaneous carriage of multiple virulence genes and genetically considerable diversity were very common among CA-MRSA from pediatric patients in Shanghai. ST59-MRSA-IV with t437 was still the most predominant type. The combination of

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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).

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  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. 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

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. [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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and...

  17. 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... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and...

  18. 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... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and...

  19. 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... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and...

  20. 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... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and...

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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.

  9. [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.

  10. 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.

  11. [Zosteriform lichen aureus. Pediatric clinical case].

    PubMed

    Rivera-Rodríguez, Álvaro; Hernández Ostiz, Sergio; Morales-Moya, Ana L; Prieto-Torres, Lucía; Álvarez-Salafranca, Marcial; Ara Martín, Mariano

    2017-04-01

    Lichen aureus is a rare pigmented purpuric dermatosis. We present an unusual case because of the pediatric age and the great number of lesions with zosteriform distribution. He is a 10-yearold boy, with a brownish, smaller than 1 cm, sharp edges, lichenified surface, asymptomatic macule, over the inner aspect of the left leg with a zosteriform distribution. The histology showed a band-like inflammatory infiltrate in the superficial dermis, composed of lymphocytes, histiocytes, erythrocytes and haemosiderin. He was diagnosed with zosteriform lichen aureus and was treated with topical mometasone furoate during 3 weeks resulting in partial lightening of the macules. Lesions have remained 2 years later, and new ones have appeared in the ipsilateral ankle. We must consider differential diagnosis with other pigmented purpuric dermatitis and pigmented purpuric mycosis fungoides. There are many therapeutic options and it tends to disappear spontaneously, so new studies are necessary.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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.

  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. 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

  20. 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

  1. 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

  2. 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.

  3. Novel antibody-antibiotic conjugate eliminates intracellular S. aureus.

    PubMed

    Lehar, Sophie M; Pillow, Thomas; Xu, Min; Staben, Leanna; Kajihara, Kimberly K; Vandlen, Richard; DePalatis, Laura; Raab, Helga; Hazenbos, Wouter L; Morisaki, J Hiroshi; Kim, Janice; Park, Summer; Darwish, Martine; Lee, Byoung-Chul; Hernandez, Hilda; Loyet, Kelly M; Lupardus, Patrick; Fong, Rina; Yan, Donghong; Chalouni, Cecile; Luis, Elizabeth; Khalfin, Yana; Plise, Emile; Cheong, Jonathan; Lyssikatos, Joseph P; Strandh, Magnus; Koefoed, Klaus; Andersen, Peter S; Flygare, John A; Wah Tan, Man; Brown, Eric J; Mariathasan, Sanjeev

    2015-11-19

    Staphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy. Here we confirm that intracellular reservoirs of S. aureus in mice comprise a virulent subset of bacteria that can establish infection even in the presence of vancomycin, and we introduce a novel therapeutic that effectively kills intracellular S. aureus. This antibody-antibiotic conjugate consists of an anti-S. aureus antibody conjugated to a highly efficacious antibiotic that is activated only after it is released in the proteolytic environment of the phagolysosome. The antibody-antibiotic conjugate is superior to vancomycin for treatment of bacteraemia and provides direct evidence that intracellular S. aureus represents an important component of invasive infections.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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%.

  16. 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

  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. 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.

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Staphylococcus aureus 'Down Under': contemporary epidemiology of S. aureus in Australia, New Zealand, and the South West Pacific.

    PubMed

    Williamson, D A; Coombs, G W; Nimmo, G R

    2014-07-01

    The clinical and molecular epidemiology of Staphylococcus aureus disease has changed considerably over the past two decades, particularly with the emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA) clones. Indeed, some of the first global descriptions of CA-MRSA were from remote indigenous communities in Western Australia, and from Pacific Peoples in New Zealand. The epidemiology of S. aureus infections in the South West Pacific has several unique features, largely because of the relative geographical isolation and unique indigenous communities residing in this region. In particular, a number of distinct CA-MRSA clones circulate in Australia and New Zealand, such as sequence type (ST) 93 methicillin-resistant S. aureus (MRSA) (Queensland clone) and clonal complex 75 S. aureus (Staphylococcus argenteus) in Australia, and ST30 MRSA (Southwest Pacific clone) in New Zealand. In addition, there is a disproportionate burden of S. aureus disease in indigenous paediatric populations, particularly in remote Aboriginal communities in Australia, and in Pacific Peoples and Maori in New Zealand. In this review, we provide a contemporary overview of the clinical and molecular epidemiology of S. aureus disease in the South West Pacific region, with a particular focus on features distinct to this region.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. [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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Molecular Characterization of a Catalase-Negative Methicillin-Susceptible Staphylococcus aureus subsp. aureus Strain Collected from a Patient with Cutaneous Abscess

    PubMed Central

    Johnson, Ryan C.; Crawford, Katrina; Lanier, Jeffrey B.; Merrell, D. Scott

    2014-01-01

    We describe a cutaneous abscess caused by catalase-negative methicillin-susceptible Staphylococcus aureus subsp. aureus in a patient who was concomitantly colonized with virulent USA300 methicillin-resistant S. aureus (MRSA). Sequencing of the katA gene demonstrated a thymine insertion leading to a frameshift mutation and premature truncation of catalase to 21 amino acids. PMID:24131694

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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/ .

  11. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches.

    PubMed

    Fogarty, Lisa R; Haack, Sheridan K; Johnson, Heather E; Brennan, Angela K; Isaacs, Natasha M; Spencer, Chelsea

    2015-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA+femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci 'excellent' recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  12. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

    USGS Publications Warehouse

    Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  13. 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

  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. 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.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.

  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. 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

  6. 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.

  7. 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.

  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. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Optical measurements of dynamic adhesive forces between bacteria and protein-coated surfaces

    NASA Astrophysics Data System (ADS)

    Simpson, Kathryn H.; Bowden, Gabriela; Hook, Magnus; Anvari, Bahman

    2003-06-01

    Bacterial adhesion to host tissue is an initial step in the infectious process. Staphylococcus aureus, a major human pathogen, has covalently anchored cell surface adhesins called microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) which mediate specific adhesion to extracellular matrix (ECM) molecules. Understanding MSCRAMM binding is potentially useful in developing effective antibacterial drugs. In this study, optical tweezers were used in conjunction with a quadrant photodetector to measure adhesive forces between MSCRAMMs and surfaces coated with the ECM molecule fibronectin. Using a piezoelectrically driven stage, a fibronectin-coated microsphere adherent to a coverslip was brought into contact with a cell optically trapped at 830 nm. The microsphere was subsequently moved away from the cell, and a quadrant photodiode monitored the cell displacement from the trap center during the detachment process. The photodetector voltage signals were subsequently converted into the adhesive forces between MSCRAMMs and fibronectin based on a calibration using Stoke"s law for viscous drag. Optical detection of the trapped bead displacement allowed us to study both the dynamics of the detachment process and observe the effects of various loading rates. This technique can be extended to identify the contributions of various MSCRAMM domains to adhesion in order to develop new methods of treating infections.

  4. 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

  5. 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.

  6. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary 2013

    DTIC Science & Technology

    2015-01-06

    Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary 2013 NMCPHC-EDC-TR-44...December 2014 EpiData Center Department Abstract Methicillin-resistant Staphylococcus aureus (MRSA) infections are a national concern for public...Navy (DON) beneficiary populations. This report provides a summary of Methicillin-resistant Staphylococcus aureus (MRSA) incidence and prevalence

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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…

  16. 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.

  17. 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.

  18. 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.

  19. 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...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 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...

  1. 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...

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Microbial Susceptibility and Plasmid Profiles of Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus

    PubMed Central

    Shahkarami, Fatemeh; Rashki, Ahmad; Rashki Ghalehnoo, Zahra

    2014-01-01

    Background: Today, significant increase in the prevalence and emergence of methicillin-resistant Staphylococcus aureus (MRSA) is a serious public health concern and is likely to have a dramatic negative impact on many current medical practices. Therefore, identification of MRSA strains is important for both clinical and epidemiological implications. Objectives: The present study was carried out to determine the frequency of methicillin resistant; antibiotic susceptibility and plasmid profiles of S. aureus recovered from different types of clinical samples of patients in Zabol, Iran. Material and Methods: Clinical samples from 500 outpatient and hospitalized patients were tested for S. aureus. The susceptibility of 106 S. aureus to 11 antibiotics was evaluated by the disk diffusion method and Etest oxacillin strips. The presence of mecA gene was investigated by polymerase chain reaction (PCR). The plasmid profile patterns of all isolates were determined by a modified alkaline lysis method. Results: A total of 67 (63.20%) strains were found to be MRSA isolates. Most of MRSA isolates showed high level of resistance to ampicillin, erythromycin, nalidixic acid, penicillin, and tetracycline. Twenty-six percent of MRSA isolates showed high level of resistance to oxacillin (minimum inhibitory concentration [MIC] ≥ 256 μg/mL). mecA gene was detected among 62 MRSA isolates. Totally, 75 isolates of both strains harbored plasmid. Conclusions: Resistance to oxacillin and other antibiotics was high, and most of the isolates were found to be multi-drug resistance (MDR). Plasmid analysis of representative S. aureus isolates also demonstrates the presence of a wide range of plasmid sizes, with no consistent relationship between plasmid profiles and resistance phenotypes. Regular surveillance of hospital infections and monitoring of their antibiotic sensitivity patterns are required to reduce MRSA prevalence. High prevalence and multi-drug resistance of MRSA isolates in southeast

  2. 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

  3. Performance of the Chromogenic Medium CHROMagar Staph Aureus and the Staphychrom Coagulase Test in the Detection and Identification of Staphylococcus aureus in Clinical Specimens

    PubMed Central

    Carricajo, Anne; Treny, Axel; Fonsale, Nathalie; Bes, Michele; Reverdy, Marie Elisabeth; Gille, Yves; Aubert, Gerald; Freydiere, Anne Marie

    2001-01-01

    CHROMagar Staph aureus (CSAM) (CHROMagar Microbiology, Paris, France) is a new chromogenic medium designed to enable detection of colonies of Staphylococcus aureus by their pink color. A total of 775 specimens were cultured in parallel on CHROMagar Staph aureus and conventional media. Among the 267 S. aureus strains recovered on at least one medium, 263 were isolated on CSAM medium (sensitivity, 98.5%), and 245 (sensitivity, 91.8%) were isolated on conventional media. The specificity of presumptive identification of S. aureus on the basis of pink colony color on CSAM medium was 97% (493 of 508). This specificity increased to 100% when coagulase detection with the Staphychrom coagulase test was added and to 98.8% when S. aureus surface components were detected by agglutination in the Pastorex Staph Plus test. Susceptibility testing of 67 S. aureus strains, performed in parallel on pink CSAM colonies and on colonies grown on blood agar, gave similar results. Thus, rapid and accurate recognition and identification of S. aureus isolates were achieved with CSAM as the primary isolation medium, followed by the staphylocoagulase Staphychrom test. Antimicrobial susceptibility testing (disk-diffusion method or ATB STAPH System) can be performed directly on pink CSAM colonies. PMID:11427572

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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

  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. 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

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  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. Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System

    PubMed Central

    Canovas, Jaime; Baldry, Mara; Bojer, Martin S.; Andersen, Paal S.; Grzeskowiak, Piotr K.; Stegger, Marc; Damborg, Peter; Olsen, Christian A.; Ingmer, Hanne

    2016-01-01

    Staphylococci are associated with both humans and animals. While most are non-pathogenic colonizers, Staphylococcus aureus is an opportunistic pathogen capable of causing severe infections. S. aureus virulence is controlled by the agr quorum sensing system responding to secreted auto-inducing peptides (AIPs) sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus agr. The dog pathogen, Staphylococcus schleiferi, expressed the most potent inhibitory activity and was active against all four agr classes found in S. aureus. By employing a S. aureus strain encoding a constitutively active AIP receptor we show that the activity is mediated via agr. Subsequent cloning and heterologous expression of the S. schleiferi AIP in S. aureus demonstrated that this molecule was likely responsible for the inhibitory activity, and further proof was provided when pure synthetic S. schleiferi AIP was able to completely abolish agr induction of an S. aureus reporter strain. To assess impact on S. aureus virulence, we co-inoculated S. aureus and S. schleiferi in vivo in the Galleria mellonella wax moth larva, and found that expression of key S. aureus virulence factors was abrogated. Our data show that the S. aureus agr locus is highly responsive to other staphylococcal species suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci will significantly

  20. Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System.

    PubMed

    Canovas, Jaime; Baldry, Mara; Bojer, Martin S; Andersen, Paal S; Grzeskowiak, Piotr K; Stegger, Marc; Damborg, Peter; Olsen, Christian A; Ingmer, Hanne

    2016-01-01

    Staphylococci are associated with both humans and animals. While most are non-pathogenic colonizers, Staphylococcus aureus is an opportunistic pathogen capable of causing severe infections. S. aureus virulence is controlled by the agr quorum sensing system responding to secreted auto-inducing peptides (AIPs) sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus agr. The dog pathogen, Staphylococcus schleiferi, expressed the most potent inhibitory activity and was active against all four agr classes found in S. aureus. By employing a S. aureus strain encoding a constitutively active AIP receptor we show that the activity is mediated via agr. Subsequent cloning and heterologous expression of the S. schleiferi AIP in S. aureus demonstrated that this molecule was likely responsible for the inhibitory activity, and further proof was provided when pure synthetic S. schleiferi AIP was able to completely abolish agr induction of an S. aureus reporter strain. To assess impact on S. aureus virulence, we co-inoculated S. aureus and S. schleiferi in vivo in the Galleria mellonella wax moth larva, and found that expression of key S. aureus virulence factors was abrogated. Our data show that the S. aureus agr locus is highly responsive to other staphylococcal species suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci will significantly

  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. 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

  3. [Examination of Staphylococcus aureus survival and growth during cheese-making process].

    PubMed

    Aoyama, Kenji; Takahashi, Chitose; Yamauchi, Yoshihiko; Sakai, Fumihiko; Igarashi, Hideo; Yanahira, Syuichi; Konishi, Hiroaki

    2008-04-01

    Inoculation tests of Staphylococcus aureus were performed to evaluate the risk of toxic hazard in cheese manufacturing processes. S. aureus was inoculated into pasteurized milk or cheese curd, and the survival and growth were examined. S. aureus grew only slightly or decreased in cell number under the manufacturing condition of semi-hard type cheese or soft-type cheese. Under the conditions of the fresh cheese making process, S. aureus slightly increased in cell number, though no enterotoxin was detected. In processed cheese, S. aureus did not grow at all. Growth inhibition of S. aureus by lactic acid produced from starter culture was suggested to be the cause of growth inhibition in the natural cheese.

  4. The growth of Staphylococcus aureus and Escherichia coli in low-direct current electric fields.

    PubMed

    Zituni, Dunya; Schütt-Gerowitt, Heidi; Kopp, Marion; Krönke, Martin; Addicks, Klaus; Hoffmann, Christian; Hellmich, Martin; Faber, Franz; Niedermeier, Wilhelm

    2014-03-01

    Electrical potentials up to 800 mV can be observed between different metallic dental restorations. These potentials produce fields in the mouth that may interfere with microbial communities. The present study focuses on the impact of different electric field strengths (EFS) on the growth of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) in vitro. Cultures of S. aureus and E. coli in fluid and gel medium were exposed to different EFS. Effects were determined by calculation of viable counts and measurement of inhibition zones. In gel medium, anodic inhibition zones for S. aureus were larger than those for E. coli at all field strength levels. In fluid medium, the maximum decrease in the viable count of S. aureus cells was at 10 V⋅m(-1). Field-treated S. aureus cells presented ruptured cell walls and disintegrated cytoplasm. Conclusively, S. aureus is more sensitive to increasing electric field strength than E. coli.

  5. Surface proteins of Staphylococcus aureus play an important role in experimental skin infection.

    PubMed

    Kwiecinski, Jakub; Jin, Tao; Josefsson, Elisabet

    2014-12-01

    Staphylococcus aureus is the most common cause of skin infections that range from mild diseases up to life-threatening conditions. Mechanisms of S. aureus virulence in those infections remain poorly studied. To investigate the impact of S. aureus surface proteins on skin infection, we used mouse models of skin abscess formation and skin necrosis, induced by a subcutaneous injection of bacteria. In the skin abscess model, a sortase-deficient S. aureus strain lacking all of its cell-wall anchored proteins was less virulent than its wild-type strain. Also, strains specifically lacking protein A, fibronecting binding proteins, clumping factor A or surface protein SasF were impaired in their virulence. When a model of dermonecrosis was studied, the S. aureus surface proteins could not be shown to be involved. In summary, surface proteins play an important role in virulence of S. aureus skin abscess infections, but not in formation of skin necrosis.

  6. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

    PubMed Central

    Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Sabat, Artur J.; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten

    2015-01-01

    Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. Principal Findings SeqSphere+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus. PMID:26360794

  7. Ultraviolet germicidal irradiation susceptibility of methicillin-resistant Staphylococcus aureus compared with methicillin-susceptible S. aureus.

    PubMed

    Green, Christopher F; Elbe, Laura A; Neal, Tyler D; Lowe, John J; Gibbs, Shawn G

    2015-11-01

    Antibiotic misuse and overuse in both the healthcare and agricultural fields have dramatically increased the prevalence of antibiotic resistance in human pathogens. Two strains of methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43330 and a wild-type) and 1 strain of methicillin-susceptible S. aureus (ATCC 25923) were challenged (9 runs in triplicate) in a preliminary study with ultraviolet germicidal irradiation (UVGI) doses ranging from 0.25 to 3.00 mJ/cm(2). The mean percent kill was calculated for each strain when compared with the control plates (no exposure to UVGI). Then, each strain was challenged (22 runs in triplicate) with UVGI doses of 2.00, 2.50, and 3.00 mJ/cm(2). The results suggest a difference between the doses required to disinfect surfaces with each strain. Assuming a standard error rate of α = 0.05, there was a significant difference in variance between the MRSA (ATCC 43330 and wild type) strains and the S. aureus (ATCC 25923) methicillin-susceptible strain.

  8. Coculture of Staphylococcus aureus with Pseudomonas aeruginosa Drives S. aureus towards Fermentative Metabolism and Reduced Viability in a Cystic Fibrosis Model

    PubMed Central

    Filkins, Laura M.; Graber, Jyoti A.; Olson, Daniel G.; Dolben, Emily L.; Lynd, Lee R.; Bhuju, Sabin

    2015-01-01

    ABSTRACT The airways of patients with cystic fibrosis are colonized with diverse bacterial communities that change dynamically during pediatric years and early adulthood. Staphylococcus aureus is the most prevalent pathogen during early childhood, but during late teens and early adulthood, a shift in microbial composition occurs leading to Pseudomonas aeruginosa community predominance in ∼50% of adults. We developed a robust dual-bacterial in vitro coculture system of P. aeruginosa and S. aureus on monolayers of human bronchial epithelial cells homozygous for the ΔF508 cystic fibrosis transmembrane conductance regulator (CFTR) mutation to better model the mechanisms of this interaction. We show that P. aeruginosa drives the S. aureus expression profile from that of aerobic respiration to fermentation. This shift is dependent on the production of both 2-heptyl-4-hydroxyquinoline N-oxide (HQNO) and siderophores by P. aeruginosa. Furthermore, S. aureus-produced lactate is a carbon source that P. aeruginosa preferentially consumes over medium-supplied glucose. We find that initially S. aureus and P. aeruginosa coexist; however, over extended coculture P. aeruginosa reduces S. aureus viability, also in an HQNO- and P. aeruginosa siderophore-dependent manner. Interestingly, S. aureus small-colony-variant (SCV) genetic mutant strains, which have defects in their electron transport chain, experience reduced killing by P. aeruginosa compared to their wild-type parent strains; thus, SCVs may provide a mechanism for persistence of S. aureus in the presence of P. aeruginosa. We propose that the mechanism of P. aeruginosa-mediated killing of S. aureus is multifactorial, requiring HQNO and P. aeruginosa siderophores as well as additional genetic, environmental, and nutritional factors. IMPORTANCE In individuals with cystic fibrosis, Staphylococcus aureus is the primary respiratory pathogen during childhood. During adulthood, Pseudomonas aeruginosa predominates and correlates

  9. 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

  10. Expanded Glucose Import Capability Affords Staphylococcus aureus Optimized Glycolytic Flux during Infection

    PubMed Central

    Vitko, Nicholas P.; Grosser, Melinda R.; Khatri, Dal; Lance, Thurlow R.

    2016-01-01

    ABSTRACT Acquisition of numerous virulence determinants affords Staphylococcus aureus greater pathogenicity than other skin-colonizing staphylococci in humans. Additionally, the metabolic adaptation of S. aureus to nonrespiratory conditions encountered during infection (e.g., hypoxia, nitric oxide, iron chelation) has been implicated as contributing to S. aureus virulence. Specifically, S. aureus has been shown to ferment glycolytic substrates in nonrespiratory environments encountered within the host. Here, we show that S. aureus has acquired unique carbohydrate transporters that facilitate the maximal uptake of host sugars and serve to support nonrespiratory growth in inflamed tissue. The carbohydrate substrates of 11 S. aureus transporters were identified, and at least four of their genes encode S. aureus glucose transporters (glcA, glcB, glcC, and glcU). Moreover, two transporter genes (glcA and glcC) are unique to S. aureus and contribute disproportionately to the nonrespiratory growth of S. aureus on glucose. Targeted inactivation of sugar transporters reduced glucose uptake and attenuated S. aureus in a murine model of skin and soft tissue infections. These data expand the evidence for metabolic adaptation of S. aureus to invasive infection and demonstrate the specific requirement for the fermentation of glucose over all other available carbohydrates. Ultimately, acquisition of foreign genes allows S. aureus to adopt a metabolic strategy resembling that of infiltrating host immune cells: high glycolytic flux coupled to lactate excretion. PMID:27329749

  11. Subinhibitory Concentrations of Perilla Oil Affect the Expression of Secreted Virulence Factor Genes in Staphylococcus aureus

    PubMed Central

    Luo, Mingjing; Li, Hongen; Dong, Jing; Wang, Jianfeng; Leng, Bingfeng; Wang, Xiaoliang; Feng, Haihua; Ren, Wenzhi; Deng, Xuming

    2011-01-01

    Background The pathogenicity of staphylococcus aureus is dependent largely upon its ability to secrete a number of virulence factors, therefore, anti-virulence strategy to combat S. aureus-mediated infections is now gaining great interest. It is widely recognized that some plant essential oils could affect the production of staphylococcal exotoxins when used at subinhibitory concentrations. Perilla [Perilla frutescens (L.) Britton], a natural medicine found in eastern Asia, is primarily used as both a medicinal and culinary herb. Its essential oil (perilla oil) has been previously demonstrated to be active against S. aureus. However, there are no data on the influence of perilla oil on the production of S. aureus exotoxins. Methodology/Principal Findings A broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of perilla oil against S. aureus strains. Hemolysis, tumour necrosis factor (TNF) release, Western blot, and real-time RT-PCR assays were performed to evaluate the effects of subinhibitory concentrations of perilla oil on exotoxins production in S. aureus. The data presented here show that perilla oil dose-dependently decreased the production of α-toxin, enterotoxins A and B (the major staphylococcal enterotoxins), and toxic shock syndrome toxin 1 (TSST-1) in both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). Conclusions/Significance The production of α-toxin, SEA, SEB, and TSST-1 in S. aureus was decreased by perilla oil. These data suggest that perilla oil may be useful for the treatment of S. aureus infections when used in combination with β-lactam antibiotics, which can increase exotoxins production by S. aureus at subinhibitory concentrations. Furthermore, perilla oil could be rationally applied in food systems as a novel food preservative both to inhibit the growth of S. aureus and to repress the production of exotoxins, particularly staphylococcal enterotoxins. PMID:21283822

  12. Methicillin-resistant Staphylococcus aureus isolates in a hospital of Shanghai

    PubMed Central

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses’ hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention. PMID:28030828

  13. Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

    PubMed

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-24

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

  14. Serious infection from Staphylococcus aureus in 2 HIV-infected patients receiving fusion inhibitor therapy.

    PubMed

    Gaughan, Elizabeth M; Ritter, Michelle L; Kumar, Princy N; Timpone, Joseph G

    2008-05-01

    Fusion inhibitors are novel antiretroviral agents, administered as subcutaneous injections, approved for use in treatment-experienced HIV-infected patients. HIV-infected patients are at increased risk for Staphylococcus aureus colonization, specifically with methicillin-resistant S aureus (MRSA), and subsequent systemic infection. We present the cases of 2 patients without a history of MRSA infection in whom a series of severe S aureus infections developed after fusion inhibitor therapy.

  15. A Prophage in Diabetic Foot Ulcer-Colonizing Staphylococcus aureus Impairs Invasiveness by Limiting Intracellular Growth.

    PubMed

    Rasigade, Jean-Philippe; Dunyach-Rémy, Catherine; Sapin, Anaïs; Messad, Nourredine; Trouillet-Assant, Sophie; Dupieux, Céline; Lavigne, Jean-Philippe; Laurent, Frédéric

    2016-11-15

    The mechanisms that drive the transition from commensality to invasiveness in Staphylococcus aureus are poorly understood. We recently reported that >50% of S. aureus isolates from uninfected diabetic foot ulcers in French patients harbor a prophage, ROSA-like, that is absent from invasive isolates from diabetic foot infections, including osteomyelitis. Here we show that the ROSA-like insertion abolishes the ability of S. aureus to replicate within osteoblasts, the bone-forming cells, greatly reducing damage to infected cells. These results unravel an important mechanism by which particular S. aureus strains are maintained in a commensal state in diabetic foot ulcers.

  16. Topography of distinct Staphylococcus aureus types in chronic wounds of patients with epidermolysis bullosa.

    PubMed

    van der Kooi-Pol, Magdalena M; Sadaghian Sadabad, Mehdi; Duipmans, José C; Sabat, Artur J; Stobernack, Tim; Omansen, Till F; Westerhout-Pluister, Gerlinde N; Jonkman, Marcel F; Harmsen, Hermie J M; van Dijl, Jan Maarten

    2013-01-01

    The opportunistic pathogen Staphylococcus aureus is known to interfere with wound healing and represents a significant risk factor for wound infections and invasive disease. It is generally assumed that one individual is predominantly colonized by one S. aureus type. Nevertheless, patients with the genetic blistering disease epidermolysis bullosa (EB) often carry multiple S. aureus types. We therefore investigated whether different S. aureus types are present in individual wounds of EB patients and, if so, how they are spatially distributed. The staphylococcal topography in chronic wounds was mapped by replica-plating of used bandages and subsequent typing of S. aureus isolates. Individual chronic wounds of five patients contained up to six different S. aureus types. Unexpectedly, distinct S. aureus types formed micro-colonies that were located in close proximity and sometimes even overlapped. While some adjacent S. aureus isolates were closely related, others belonged to distinct molecular complexes. We conclude that the general assumption that one individual is predominantly colonized by one type of S. aureus does not apply to chronic wounds of EB patients. We consider this observation important, not only for EB patients, but also for other patients with chronic wounds in view of the potential risk for severe staphylococcal infections.

  17. Superantigen-Producing Staphylococcus aureus Elicits Systemic Immune Activation in a Murine Wound Colonization Model.

    PubMed

    Kim, Choon K; Karau, Melissa J; Greenwood-Quaintance, Kerryl E; Tilahun, Ashenafi Y; Krogman, Ashton; David, Chella S; Pritt, Bobbi S; Patel, Robin; Rajagopalan, Govindarajan

    2015-12-08

    Staphylococcus aureus, the most common cause of wound infection, produces several exotoxins, including superantigens (SAgs). SAgs are the potent activators of the immune system. Given this unique property, we hypothesized that SAgs produced by S. aureus in wounds would have local, as well as systemic immunologic effects. We tested our hypothesis using a novel staphylococcal skin wound infection model in transgenic mice expressing HLA-DR3. Skin wounds were left uninfected or colonized with S. aureus strains producing SAgs or an isogenic strain not producing any SAg. Animals with wounds challenged with SAg-producing S. aureus had increased morbidity and lower serum IL-17 levels compared to those challenged with the SAg non-producing S. aureus (p = 0.027 and p = 0.032, respectively). At Day 8 following microbial challenge, compared to mice with uninfected wounds, the proportion of Vβ8⁺CD4⁺ T cells was increased, while the proportion of Vβ8⁺CD8⁺ T cells was decreased only in the spleens of mice challenged with SAg-producing S. aureus (p < 0.001). No such changes were measured in mice challenged with SAg non-producing S. aureus. Lungs, livers and kidneys from mice challenged with SAg-producing, but not SAg non-producing, S. aureus showed inflammatory changes. Overall, SAg-mediated systemic immune activation in wounds harboring S. aureus may have clinical implications.

  18. Altered composition of epidermal lipids correlates with Staphylococcus aureus colonization status in Atopic Dermatitis.

    PubMed

    Li, S; Villarreal, M; Stewart, S; Choi, J; Indra, G; Babineau, D C; Philpot, C; David, G; Yoshida, T; Boguniewicz, M; Hanifin, J; Beck, L A; Leung, D; Simpson, E; Indra, A K

    2017-02-28

    Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by disrupted epidermal barrier functions.(1) Stratum corneum (SC) consists of corneocytes and a lipid-rich extracellular matrix, which plays a key role in epidermal permeability barrier (EPB) functions.(2,3) Major lipid constituents of the SC are ceramides (CERs), free fatty acids (FFAs), cholesterol and triglycerides (TGs).(2,3) Staphylococcus aureus (S.aureus) colonization is an important trigger of AD.(4) Comprehensive profiling of SC lipids using S.aureus colonization status, and association between S.aureus colonization and skin lipid composition, has never been documented. This article is protected by copyright. All rights reserved.

  19. Statins and Antimicrobial Effects: Simvastatin as a Potential Drug against Staphylococcus aureus Biofilm

    PubMed Central

    Franco, Gilson Cesar; Schwartz-Filho, Humberto Osvaldo; de Andrade, Eduardo Dias

    2015-01-01

    Statins are important lipid-lowering agents with other pleiotropic effects. Several studies have explored a possible protective effect of statins to reduce the morbidity and mortality of many infectious diseases. Staphylococcus aureus is one of the main pathogens implicated in nosocomial infections; its ability to form biofilms makes treatment difficult. The present study observed the MIC of atorvastatin, pravastatin and simvastatin against S. aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis. Simvastatin was the only agent with activity against clinical isolates and reference strains of methicilin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). Thus, the effects of simvastatin on the growth, viability and biofilm formation of S. aureus were tested. In addition, a possible synergistic effect between simvastatin and vancomycin was evaluated. Simvastatin’s MIC was 15.65 µg/mL for S. aureus 29213 and 31.25 µg/mL for the other strains of S. aureus. The effect of simvastatin was bactericidal at 4xMIC and bacteriostatic at the MIC concentration. No synergistic effect was found between simvastatin and vancomycin. However, the results obtained against S. aureus biofilms showed that, in addition to inhibiting adhesion and biofilm formation at concentrations from 1/16xMIC to 4xMIC, simvastatin was also able to act against mature biofilms, reducing cell viability and extra-polysaccharide production. In conclusion, simvastatin showed pronounced antimicrobial activity against S. aureus biofilms, reducing their formation and viability. PMID:26020797

  20. The Role of Staphylococcus aureus Virulence Factors in Skin Infection and Their Potential as Vaccine Antigens

    PubMed Central

    Lacey, Keenan A.; Geoghegan, Joan A.; McLoughlin, Rachel M.

    2016-01-01

    Staphylococcus aureus (S. aureus) causes the vast majority of skin and soft tissue infections (SSTIs) in humans. S. aureus has become increasingly resistant to antibiotics and there is an urgent need for new strategies to tackle S. aureus infections. Vaccines offer a potential solution to this epidemic of antimicrobial resistance. However, the development of next generation efficacious anti-S. aureus vaccines necessitates a greater understanding of the protective immune response against S. aureus infection. In particular, it will be important to ascertain if distinct immune mechanisms are required to confer protection at distinct anatomical sites. Recent discoveries have highlighted that interleukin-17-producing T cells play a particularly important role in the immune response to S. aureus skin infection and suggest that vaccine strategies to specifically target these types of T cells may be beneficial in the treatment of S. aureus SSTIs. S. aureus expresses a large number of cell wall-anchored (CWA) proteins, which are covalently attached to the cell wall peptidoglycan. The virulence potential of many CWA proteins has been demonstrated in infection models; however, there is a paucity of information regarding their roles during SSTIs. In this review, we highlight potential candidate antigens for vaccines targeted at protection against SSTIs. PMID:26901227

  1. Presence of Staphylococcus aureus on university dance studio floors and barres: a preliminary investigation.

    PubMed

    Unsworth, Desiree A; Russell, Jeffrey A; Martiny, Adam C

    2014-01-01

    Staphylococcus aureus (S. aureus) is a bacterium associated with various infectious diseases. Not only has the bacterium been detected in sports environments, the reported incidences of S. aureus infections have steadily increased in athletic teams. However, in spite of similarities between sports and dance facilities, to our knowledge no previous study has examined the presence of this bacterium in the dance environment. We hypothesized that S. aureus would be present in a university's dance studios, and that it would be extant in higher concentrations inside versus outside the studios. Using common microbiological culturing methods, samples were gathered from floors and barres in three studios of a single university, as well as from outside floors and railings near the studios and a conference room used by dancers. Confirming our hypothesis, we detected S. aureus in every dance studio sample (0.03 to 0.38 cfu/cm 2 ). Supporting our second hypothesis, we found that average S. aureus concentrations from the three studios were significantly higher compared to both outside and conference room samples (P ≤ 0.001). The latter two locations did not yield any S. aureus concentrations. Control samples developed as expected. The results of this study suggest that S. aureus bacteria are common on the flooring and barres of university dance studios, with the bacterial concentrations possibly dependent on the hours of usage of these surfaces. Whether the presence of S. aureus in dance studios presents a health risk to dancers should be studied further.

  2. The complex biology and contribution of Staphylococcus aureus in atopic dermatitis, current and future therapies.

    PubMed

    Hepburn, L; Hijnen, D J; Sellman, B R; Mustelin, T; Sleeman, M A; May, R D; Strickland, I

    2016-10-25

    Atopic dermatitis (AD) is a complex, chronic inflammatory skin disorder affecting more than 10% of UK children and is a major cause of occupation-related disability. A subset of patients, particularly those with severe AD, are persistently colonised with Staphylococcus aureus (S. aureus) and exacerbation of disease is commonly associated with this bacterium by virtue of increased inflammation and allergic sensitisation, aggravated by skin barrier defects. Understanding the complex biology of S. aureus is an important factor when developing new drugs to combat infection. S. aureus generates exoproteins that enable invasion and dissemination within the host skin but can also damage the skin and activate the host immune system. Antibiotics are often used by dermatologists to aid clearance of S. aureus; however, these are becoming less effective and chronic usage discouraged with the emergence of multiple antibiotic-resistant strains. New ways to target S. aureus using monoclonal antibodies and vaccines are now being developed. This review will attempt to evaluate the key biology of S. aureus, current treatment of S. aureus infections in atopic dermatitis and recent advances in developing new anti-S. aureus therapies that have potential in severe AD. This article is protected by copyright. All rights reserved.

  3. Staphylococcus aureus Contamination of Environmental Surfaces in Households with Children Infected with Methicillin-Resistant S. aureus

    PubMed Central

    Fritz, Stephanie A.; Hogan, Patrick G.; Singh, Lauren N.; Thompson, Ryley M.; Wallace, Meghan A.; Whitney, Krista; Al-Zubeidi, Duha; Burnham, Carey-Ann D.; Fraser, Victoria J.

    2014-01-01

    IMPORTANCE Household environmental surfaces may serve as vectors for acquisition and spread of methicillin-resistant Staphylococcus aureus (MRSA) among household members, though few studies have evaluated which objects are important MRSA reservoirs. OBJECTIVES Determine the prevalence of environmental MRSA contamination in households of children with MRSA infection; define the molecular epidemiology of environmental, pet, and human MRSA strains within households; and identify factors associated with household MRSA contamination. DESIGN, SETTING, AND PARTICIPANTS Fifty households of children with active or recent culture-positive community-associated MRSA infection were enrolled from 2012–13 at St. Louis Children’s Hospital and community pediatric practices affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium. MAIN OUTCOMES AND MEASURES Participants’ nares, axillae, and inguinal folds were cultured to detect S. aureus colonization. Twenty-one environmental surfaces and pet dogs and cats were cultured. Molecular typing of S. aureus strains was performed by repetitive-sequence polymerase chain reaction to determine strain relatedness within households. RESULTS MRSA was recovered from environmental surfaces in 23 (46%) households, most frequently from the participant’s bed linens (18%), television remote control (16%), and bathroom hand towel (15%). MRSA colonized 12% of dogs and 7% of cats. At least 1 surface was contaminated with a strain type matching the participant’s isolate in 20 (40%) households. Participants colonized with S. aureus had a higher proportion of MRSA-contaminated surfaces (0.15 ± 0.17) than non-colonized participants [0.03± 0.06; mean difference 0.12 (95% CI 0.05, 0.20)]. A greater number of individuals per 1000 ft2 was also associated with a higher proportion of MRSA-contaminated surfaces (β=0.34, p=0.03). The frequency of cleaning household surfaces was not associated with S. aureus

  4. Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

    PubMed

    Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

    2015-12-01

    Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. Decrease of Staphylococcus aureus Virulence by Helcococcus kunzii in a Caenorhabditis elegans Model

    PubMed Central

    Ngba Essebe, Christelle; Visvikis, Orane; Fines-Guyon, Marguerite; Vergne, Anne; Cattoir, Vincent; Lecoustumier, Alain; Lemichez, Emmanuel; Sotto, Albert; Lavigne, Jean-Philippe; Dunyach-Remy, Catherine

    2017-01-01

    Social bacterial interactions are considered essential in numerous infectious diseases, particularly in wounds. Foot ulcers are a common complication in diabetic patients and these ulcers become frequently infected. This infection is usually polymicrobial promoting cell-to-cell communications. Staphylococcus aureus is the most prevalent pathogen isolated. Its association with Helcococcus kunzii, commensal Gram-positive cocci, is frequently described. The aim of this study was to assess the impact of co-infection on virulence of both H. kunzii and S. aureus strains in a Caenorhabditis elegans model. To study the host response, qRT-PCRs targeting host defense genes were performed. We observed that H. kunzii strains harbored a very low (LT50: 5.7 days ± 0.4) or an absence of virulence (LT50: 6.9 days ± 0.5). In contrast, S. aureus strains (LT50: 2.9 days ± 0.4) were significantly more virulent than all H. kunzii (P < 0.001). When H. kunzii and S. aureus strains were associated, H. kunzii significantly reduced the virulence of the S. aureus strain in nematodes (LT50 between 4.4 and 5.2 days; P < 0.001). To evaluate the impact of these strains on host response, transcriptomic analysis showed that the ingestion of S. aureus led to a strong induction of defense genes (lys-5, sodh-1, and cyp-37B1) while H. kunzii did not. No statistical difference of host response genes expression was observed when C. elegans were infected with either S. aureus alone or with S. aureus + H. kunzii. Moreover, two well-characterized virulence factors (hla and agr) present in S. aureus were down-regulated when S. aureus were co-infected with H. kunzii. This study showed that H. kunzii decreased the virulence of S. aureus without modifying directly the host defense response. Factor(s) produced by this bacterium modulating the staphylococci virulence must be investigated. PMID:28361041

  12. Decrease of Staphylococcus aureus Virulence by Helcococcus kunzii in a Caenorhabditis elegans Model.

    PubMed

    Ngba Essebe, Christelle; Visvikis, Orane; Fines-Guyon, Marguerite; Vergne, Anne; Cattoir, Vincent; Lecoustumier, Alain; Lemichez, Emmanuel; Sotto, Albert; Lavigne, Jean-Philippe; Dunyach-Remy, Catherine

    2017-01-01

    Social bacterial interactions are considered essential in numerous infectious diseases, particularly in wounds. Foot ulcers are a common complication in diabetic patients and these ulcers become frequently infected. This infection is usually polymicrobial promoting cell-to-cell communications. Staphylococcus aureus is the most prevalent pathogen isolated. Its association with Helcococcus kunzii, commensal Gram-positive cocci, is frequently described. The aim of this study was to assess the impact of co-infection on virulence of both H. kunzii and S. aureus strains in a Caenorhabditis elegans model. To study the host response, qRT-PCRs targeting host defense genes were performed. We observed that H. kunzii strains harbored a very low (LT50: 5.7 days ± 0.4) or an absence of virulence (LT50: 6.9 days ± 0.5). In contrast, S. aureus strains (LT50: 2.9 days ± 0.4) were significantly more virulent than all H. kunzii (P < 0.001). When H. kunzii and S. aureus strains were associated, H. kunzii significantly reduced the virulence of the S. aureus strain in nematodes (LT50 between 4.4 and 5.2 days; P < 0.001). To evaluate the impact of these strains on host response, transcriptomic analysis showed that the ingestion of S. aureus led to a strong induction of defense genes (lys-5, sodh-1, and cyp-37B1) while H. kunzii did not. No statistical difference of host response genes expression was observed when C. elegans were infected with either S. aureus alone or with S. aureus + H. kunzii. Moreover, two well-characterized virulence factors (hla and agr) present in S. aureus were down-regulated when S. aureus were co-infected with H. kunzii. This study showed that H. kunzii decreased the virulence of S. aureus without modifying directly the host defense response. Factor(s) produced by this bacterium modulating the staphylococci virulence must be investigated.

  13. Detection of Methicillin Resistance and Various Virulence Factors in Staphylococcus aureus Strains Isolated from Nasal Carriers

    PubMed Central

    Dağı, Hatice Türk; Fındık, Duygu; Demirel, Gamze; Arslan, Uğur

    2015-01-01

    Background: Staphylococus aureus can be found as a commensal on skin and nasal flora or it may cause local and invasive infections. S. aureus has a large number of virulence factors. Aims: To investigate the methicillin resistance and frequency of various virulence factors in S. aureus nasal isolates. Study Design: Descriptive study. Methods: Nasal samples collected from university students were cultured in media. S. aureus was identified by conventional methods and the Staphyloslide latex test (Becton Dickinson, Sparks, USA). Antibiotic susceptibility tests were conducted, and the methicillin resistance was determined. The mecA, nuc, pvl and staphylococcal toxin genes were examined by polymerase chain reaction (PCR). Results: S. aureus was isolated in 104 of 600 (17.3%) nasal samples. In total, 101 (97.1%) S. aureus isolates were methicillin-sensitive and the remaining 3 (2.9%) were methicillin-resistant. Furthermore, all but five isolates carried at least one staphylococcal enterotoxin gene, with seg being predominant. The tst and eta genes were determined in 29 (27.9%), and 3 (2.9%) isolates, respectively. None of the S. aureus isolates harbored see, etb, and pvl genes. Conclusion: A moderate rate of S. aureus carriage and low frequency of MRSA were detected in healthy students. S. aureus isolates had a high prevalence of staphylococcal enterotoxin genes and the tst gene. In this study, a large number of virulence factors were examined in S. aureus nasal isolates, and the data obtained from this study can be used for monitoring the prevalence of virulence genes in S. aureus strains isolated from nasal carriers. PMID:26167341

  14. Capsule Expression and Genotypic Differences among Staphylococcus aureus Isolates from Patients with Chronic or Acute Osteomyelitis▿

    PubMed Central

    Lattar, Santiago M.; Tuchscherr, Lorena P. N.; Caccuri, Roberto L.; Centrón, Daniela; Becker, Karsten; Alonso, Claudio A.; Barberis, Claudia; Miranda, Graciela; Buzzola, Fernanda R.; von Eiff, Christof; Sordelli, Daniel O.

    2009-01-01

    There is ample evidence that Staphylococcus aureus capsular polysaccharide (CP) promotes virulence. Loss of capsule expression, however, may lead to S. aureus persistence in a chronically infected host. This study was conducted to determine the relative prevalence of nonencapsulated S. aureus in patients with chronic and acute osteomyelitis. Only 76/118 (64%) S. aureus isolates from patients with osteomyelitis expressed CP, whereas all 50 isolates from blood cultures of patients with infections other than osteoarticular infections expressed CP (P = 0.0001). A significantly higher prevalence of nonencapsulated S. aureus was found in patients with chronic osteomyelitis (53%) than in those with acute osteomyelitis (21%) (P = 0.0046). S. aureus isolates obtained from multiple specimens from five of six patients with chronic osteomyelitis exhibited phenotypic (expression of CP, α-hemolysin, β-hemolysin, slime, and the small-colony variant phenotype) and/or genotypic (pulsed-field gel electrophoresis and spa typing) differences. Nonencapsulated S. aureus was recovered from at least one specimen from each chronic osteomyelitis patient. Fourteen isolates obtained from two patients with acute osteomyelitis were indistinguishable from each other within each group, and all produced CP5. In conclusion, we demonstrated that nonencapsulated S. aureus is more frequently isolated from patients with chronic osteomyelitis than from those with acute osteomyelitis, suggesting that loss of CP expression may be advantageous to S. aureus during chronic infection. Our findings on multiple S. aureus isolates from individual patients allow us to suggest that selection of nonencapsulated S. aureus is likely to have occurred in the patient during long-term bone infection. PMID:19273557

  15. 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).

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. [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.

  1. 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.

  2. Antimicrobial Susceptibility Profiles of Staphylococcus aureus Isolates Recovered from Humans, Environmental Surfaces, and Companion Animals in Households of Children with Community-Onset Methicillin-Resistant S. aureus Infections.

    PubMed

    Morelli, John J; Hogan, Patrick G; Sullivan, Melanie L; Muenks, Carol E; Wang, Jeffrey W; Thompson, Ryley M; Burnham, Carey-Ann D; Fritz, Stephanie A

    2015-10-01

    Our objective was to determine the antibiotic susceptibility profiles of Staphylococcus aureus isolates recovered from 110 households of children with community-onset methicillin-resistant S. aureus (MRSA) infections. Cultures were obtained from household members, household objects, and dogs and cats, yielding 1,633 S. aureus isolates. The S. aureus isolates were heterogeneous, although more than half were methicillin resistant. The highest proportion of MRSA was found in bathrooms. The majority of isolates were susceptible to antibiotics prescribed in outpatient settings.

  3. The Characteristics of Staphylococcus aureus Small Colony Variant Isolated from Chronic Mastitis at a Dairy Farm in Yunnan Province, China

    PubMed Central

    Zhu, Li-li; Zou, Feng-cai; Yan, Yu-lin; Wang, Qi-hui; Shi, Yong-qiang; Qu, Wei-jie

    2016-01-01

    Staphylococcus aureus is a major causative agent leading to bovine mastitis and has specific phonotypical characteristics including small colony, slow growth, and decreased hemolysis, therefore named as the small colony variants (SCVs). Out of 30 tested samples of the chronic S. aureus cases, one strain of SCVs (S. aureus SCV22) was isolated along with its parental strains (S. aureus11). S. aureus SCV22 showed a slow growth rate when it is compared with the parental strain. However, their resistant patterns were similar. Meanwhile, S. aureus SCV22 depicted the lower rate of apoptosis in bovine mammary epithelial cells. These findings of the present study presented the unique characteristics of S. aureus SCV22 for the first time in Yunnan province, which provided a prophase foundation for further study about the pathogenesis of S. aureus SCVs in chronic mastitis. PMID:27066529

  4. A novel δ-hemolysis screening method for detecting heteroresistant vancomycin-intermediate Staphylococcus aureus and vancomycin-intermediate S. aureus.

    PubMed

    Cafiso, V; Bertuccio, T; Spina, D; Purrello, S; Blandino, G; Stefani, Stefania

    2012-05-01

    We assessed a new screening method, based on δ-hemolysin production in the presence of 6 mg/liter vancomycin, to distinguish heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) from vancomycin-susceptible S. aureus (VSSA). On 37 clinical methicillin-resistant S. aureus (MRSA) isolates, hVISA and VISA displayed no δ-hemolysis whereas VSSA displayed strong δ-hemolysis, showing 91.6% sensitivity. These data, supported by real-time reverse transcription PCR (real-time RT-PCR) highlighting an hld downregulation, i.e., VSSA>hVISA>VISA, define this new assay as a valid screening method.

  5. Methicillin-Resistant "Staphylococcus aureus" on Campus: A New Challenge to College Health

    ERIC Educational Resources Information Center

    Weiner, H. Richard

    2008-01-01

    As new drugs to control bacterial pathogens are developed, the organisms evolve to survive. "Staphylococcus aureus", a common organism, has steadily developed resistance to antibiotics. For more than 40 years, resistant "S. aureus" presented a formidable problem to hospitalized patients; in the past decade, however, it has begun to appear outside…

  6. 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…

  7. 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.

  8. Inhibitory effects of flavonoids on biofilm formation by Staphylococcus aureus that overexpresses efflux protein genes.

    PubMed

    Lopes, Laênia Angélica Andrade; Dos Santos Rodrigues, Jéssica Bezerra; Magnani, Marciane; de Souza, Evandro Leite; de Siqueira-Júnior, José P

    2017-03-29

    This study evaluated the efficacy of glycone (myricitrin, hesperidin and phloridzin) and aglycone flavonoids (myricetin, hesperetin and phloretin) in inhibiting biofilm formation by Staphylococcus aureus RN4220 and S. aureus SA1199B that overexpress the msrA and norA efflux protein genes, respectively. The minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC50 - defined as the lowest concentration that resulted in ≥50% inhibition of biofilm formation) of flavonoids were determined using microdilution in broth procedures. The flavonoids showed MIC >1024 μg/mL against S. aureus RN4220 and S. aureus SA1199B; however, these compounds at lower concentrations (1-256 μg/mL) showed inhibitory effects on biofilm formation by these strains. Aglycone flavonoids showed lower MBIC50 values than their respective glycone forms. The lowest MBIC50 values (1 and 4 μg/mL) were observed against S. aureus RN4220. Myricetin, hesperetin and phloretin exhibited biofilm formation inhibition >70% for S. aureus RN4220, and lower biofilm formation inhibition against S. aureus SA1199B. These results indicate that sub-MICs of the tested flavonoids inhibit biofilm formation by S. aureus strains that overexpress efflux protein genes. These effects are more strongly established by aglycone flavonoids.

  9. Prevalence and antibiogram study of Salmonella and Staphylococcus aureus in poultry meat

    PubMed Central

    Akbar, Ali; Anal, Anil Kumar

    2013-01-01

    Objective To evaluate the presence and antibiogram pattern of Salmonella and Staphylococcus aureus (S. aureus) in retail poultry meat products. Methods Foodborne pathogens (Salmonella and S. aureus) were isolated from poultry meat and confirmed with the help of biochemical and immunological test. Antibiogram of the isolates were examined by following CLSI methods. Results A total number of 209 poultry meat samples were collected and studied in this study. Out of which, 5.26% were found contaminated with Salmonella while 18.18% were found contaminated with S. aureus. All the Salmonella and S. aureus isolates were found resistant to at least one antibiotic. About 72.72% of the Salmonella isolates showed resistance to tetracycline, while S. aureus isolates were also found highly resistant to tetracycline equal to 44.73%. One of the Salmonella isolates showed multi-drug resistance to almost six antibiotics out of nine antibiotics used in the study. Multidrug resistant S. aureus isolates were also found in the study. Conclusions The study confirmed the presence of Salmonella and S. aureus in retail poultry meat. It is a potential threat to consumer health. To reduce the risk of contamination, good hygiene practices are necessary from processing to storage. PMID:23593598

  10. 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.

  11. The therapeutic effect of chlorogenic acid against Staphylococcus aureus infection through sortase A inhibition

    PubMed Central

    Wang, Lin; Bi, Chongwei; Cai, Hongjun; Liu, Bingrun; Zhong, Xiaobo; Deng, Xuming; Wang, Tiedong; Xiang, Hua; Niu, Xiaodi; Wang, Dacheng

    2015-01-01

    The emergence and wide spread of multi-drug resistant Staphylococcus aureus (S. aureus) requires the development of new therapeutic agents with alternative modes of action. Anti-virulence strategies are hoped to meet that need. Sortase A (SrtA) has attracted great interest as a potential drug target to treat infections caused by S. aureus, as many of the surface proteins displayed by SrtA function as virulence factors by mediating bacterial adhesion to specific organ tissues, invasion of host cells, and evasion of the host-immune responses. It has been suggested that inhibitors of SrtA might be promising candidates for the treatment and/or prevention of S. aureus infections. In this study, we report that chlorogenic acid (CHA), a natural compound that lacks significant anti-S. aureus activity, inhibit the activity of SrtA in vitro (IC50 = 33.86 ± 5.55 μg/ml) and the binding of S. aureus to fibrinogen (Fg). Using molecular dynamics simulations and mutagenesis assays, we further demonstrate that CHA binds to the binding sites of C184 and G192 in the SrtA. In vivo studies demonstrated that CHA prevent mice from S. aureus-induced renal abscess, resulting in a significant survival advantage. These findings indicate that CHA is a promising therapeutic compound against SrtA during S. aureus infections. PMID:26528244

  12. Human-associated methicillin-resistant Staphylococcus aureus from a subtropical recreational marine beach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reports of Staphylococcus aureus detected in marine environments have occurred since the early 1990’s. This investigation sought to isolate and characterize S. aureus from marine waters and sand at a subtropical recreational beach, with and without bathers present, in order to investigate possible s...

  13. Killing of Staphylococcus aureus via Magnetic Hyperthermia Mediated by Magnetotactic Bacteria

    PubMed Central

    Chen, Changyou; Chen, Linjie; Yi, Yong; Chen, Chuanfang

    2016-01-01

    Staphylococcus aureus is a common hospital and household pathogen. Given the emergence of antibiotic-resistant derivatives of this pathogen resulting from the use of antibiotics as general treatment, development of alternative therapeutic strategies is urgently needed. Here, we assess the feasibility of killing S. aureus cells in vitro and in vivo through magnetic hyperthermia mediated by magnetotactic bacteria that possess magnetic nanocrystals and demonstrate magnetically steered swimming. The S. aureus suspension was added to magnetotactic MO-1 bacteria either directly or after coating with anti-MO-1 polyclonal antibodies. The suspensions were then subjected to an alternating magnetic field (AMF) for 1 h. S. aureus viability was subsequently assessed through conventional plate counting and flow cytometry. We found that approximately 30% of the S. aureus cells mixed with uncoated MO-1 cells were killed after AMF treatment. Moreover, attachment between the magnetotactic bacteria and S. aureus increased the killing efficiency of hyperthermia to more than 50%. Using mouse models, we demonstrated that magnetic hyperthermia mediated by antibody-coated magnetotactic MO-1 bacteria significantly improved wound healing. These results collectively demonstrated the effective eradication of S. aureus both in vitro and in vivo, indicating the potential of magnetotactic bacterium-mediated magnetic hyperthermia as a treatment for S. aureus-induced skin or wound infections. PMID:26873320

  14. Killing of Staphylococcus aureus via Magnetic Hyperthermia Mediated by Magnetotactic Bacteria.

    PubMed

    Chen, Changyou; Chen, Linjie; Yi, Yong; Chen, Chuanfang; Wu, Long-Fei; Song, Tao

    2016-02-12

    Staphylococcus aureus is a common hospital and household pathogen. Given the emergence of antibiotic-resistant derivatives of this pathogen resulting from the use of antibiotics as general treatment, development of alternative therapeutic strategies is urgently needed. Here, we assess the feasibility of killing S. aureus cells in vitro and in vivo through magnetic hyperthermia mediated by magnetotactic bacteria that possess magnetic nanocrystals and demonstrate magnetically steered swimming. The S. aureus suspension was added to magnetotactic MO-1 bacteria either directly or after coating with anti-MO-1 polyclonal antibodies. The suspensions were then subjected to an alternating magnetic field (AMF) for 1 h. S. aureus viability was subsequently assessed through conventional plate counting and flow cytometry. We found that approximately 30% of the S. aureus cells mixed with uncoated MO-1 cells were killed after AMF treatment. Moreover, attachment between the magnetotactic bacteria and S. aureus increased the killing efficiency of hyperthermia to more than 50%. Using mouse models, we demonstrated that magnetic hyperthermia mediated by antibody-coated magnetotactic MO-1 bacteria significantly improved wound healing. These results collectively demonstrated the effective eradication of S. aureus both in vitro and in vivo, indicating the potential of magnetotactic bacterium-mediated magnetic hyperthermia as a treatment for S. aureus-induced skin or wound infections.

  15. Physicochemical characterization of Staphylococcus aureus-lysing LysK enzyme in complexes with polycationic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Staphylococcus aureus causes many serious visceral, skin, and respiratory diseases. About 90% of clinical strains are multi-drug resistant, but the use of bacteriophage lytic enzymes offers a viable alternative to antibiotic therapy. LysK, the phage K endolysin can lyse S. aureus when purified and ...

  16. Phenylboronic acid functionalized gold nanoparticles for highly sensitive detection of Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Wang, Jine; Gao, Jingqing; Liu, Dianjun; Han, Dongxue; Wang, Zhenxin

    2012-01-01

    Herein, we report a phenylboronic acid functionalized gold nanoparticle (GNP)-based colorimetric assay for rapid detection of Staphylococcus aureus (S. aureus) with high sensitivity. In this approach, GNPs can bind to S. aureus by the reaction of phenylboronic acid with the cis-diol configuration in glycans on the bacterial surface, providing a colorimetric readout of the binding event. Using this strategy, we have been able to quantify S. aureus at a concentration of 50 cells per mL (three times the standard deviation divided by the slope of the working curve) in aqueous solution.Herein, we report a phenylboronic acid functionalized gold nanoparticle (GNP)-based colorimetric assay for rapid detection of Staphylococcus aureus (S. aureus) with high sensitivity. In this approach, GNPs can bind to S. aureus by the reaction of phenylboronic acid with the cis-diol configuration in glycans on the bacterial surface, providing a colorimetric readout of the binding event. Using this strategy, we have been able to quantify S. aureus at a concentration of 50 cells per mL (three times the standard deviation divided by the slope of the working curve) in aqueous solution. Electronic supplementary information (ESI) available: Details of experimental method and additional figures are available. See DOI: 10.1039/c2nr11657j

  17. Staphylococcus aureus meningitis--a rare complication of iliacus muscle abscess.

    PubMed

    Parker, S L; Conn, K S; Ignotus, P I

    1997-07-01

    Staphylococcus aureus meningitis is a rare but well recognized condition which had a high mortality and incidence of neurological sequelae. It is usually associated with chronic underlying conditions. A case is reported of S. aureus meningitis in a previously healthy young man. The epidemiology, microbiological findings and treatment of this condition are discussed.

  18. Triple-acting antimicrobial treatment for drug-resistant and intracellular Staphylococcus aureus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

  19. Triple-acting antimicrobial treatment for drug-resistant and intracellular Staphylococcus aureus.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

  20. Triple-acting Peptidoglycan hydrolase treatment for drug-resistant and intracellular Staphylococcus aureus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

  1. Effect of a milk-derived factor on the inflammatory response to Staphylococcus aureus intramammary infection.

    PubMed

    Owens, W E; Nickerson, S C; Washburn, P J

    1992-01-15

    Daily injections of an anti-inflammatory milk-derived factor (MDF) into mice increased resistance to Staphylococcus aureus challenge, and reduced leukocyte infiltration. Intraperitoneal injection of MDF into lactating mice prior to S. aureus intramammary challenge resulted in greater milk secretory activity and less inflammation compared with untreated controls, but had little effect on the number of S. aureus recovered from mammary tissue. Infusion of MDF directly into mouse mammary glands prior to challenge reduced S. aureus recovered after challenge. Incubation of bovine mammary macrophages in medium supplemented with MDF enhanced phagocytosis of opsonized S. aureus. In addition, infusion of 5 mg MDF into uninfected bovine mammary glands 24 h prior to S. aureus challenge resulted in fewer infections (five of ten) than in control quarters (seven of nine). Repeated daily injections of 5 mg MDF into S. aureus-infected quarters increased the percent of mammary neutrophils and decreased the recovery of S. aureus, but did not eliminate infections. Intravenous injection of 8 g MDF into cows resulted in pronounced leukopenia while the accompanying effect on mammary leukocytes was less marked but followed a similar course. Results suggest that the use of MDF in mice enhanced resistance to experimental infection and was beneficial in maintaining mammary secretory activity and reducing inflammation after bacterial challenge. In the cow, MDF promoted phagocytosis in vitro and was effective against challenge when infused intramammarily.

  2. Neutrophil-generated oxidative stress and protein damage in Staphylococcus aureus.

    PubMed

    Beavers, William N; Skaar, Eric P

    2016-08-01

    Staphylococcus aureus is a ubiquitous, versatile and dangerous pathogen. It colonizes over 30% of the human population, and is one of the leading causes of death by an infectious agent. During S. aureus colonization and invasion, leukocytes are recruited to the site of infection. To combat S. aureus, leukocytes generate an arsenal of reactive species including superoxide, hydrogen peroxide, nitric oxide and hypohalous acids that modify and inactivate cellular macromolecules, resulting in growth defects or death. When S. aureus colonization cannot be cleared by the immune system, antibiotic treatment is necessary and can be effective. Yet, this organism quickly gains resistance to each new antibiotic it encounters. Therefore, it is in the interest of human health to acquire a deeper understanding of how S. aureus evades killing by the immune system. Advances in this field will have implications for the design of future S. aureus treatments that complement and assist the host immune response. In that regard, this review focuses on how S. aureus avoids host-generated oxidative stress, and discusses the mechanisms used by S. aureus to survive oxidative damage including antioxidants, direct repair of damaged proteins, sensing oxidant stress and transcriptional changes. This review will elucidate areas for studies to identify and validate future antimicrobial targets.

  3. Prevalence of Staphylococcus aureus in Imported Fish and Correlations between Antibiotic Resistance and Enterotoxigenicity.

    PubMed

    Obaidat, Mohammad M; Salman, Alaa E Bani; Lafi, Shawkat Q

    2015-11-01

    A total of 156 Staphylococcus aureus isolates were obtained from 330 imported fresh fish samples from three countries. Selective media were used for the isolation of S. aureus, and the isolates were confirmed by PCR. The isolates were tested for mecA gene, antibiotic resistance, and enterotoxin genes (sea, seb, sec, sed, see, seg, seh, and sei). Most isolates carried sea, seg, and sei genes, and seg-sei was the most frequent enterotoxin profile. About 88.5% of the S. aureus exhibited resistance to at least one antibiotic. High resistance to penicillin and ampicillin; low resistance to tetracycline, erythromycin, rifampin, and clindamycin; and very low resistance to cefotaxime, amoxicillin-clavulanic acid, gentamicin, and ciprofloxacin were exhibited by S. aureus from the three countries. In addition, some antibiotic resistance exhibited a strong correlation (P ≤ 0.01) with enterotoxigenicity in S. aureus. The study concluded that the large amount of globally traded fish increases the possibility of intercontinental transmission of enterotoxigenic and multidrug-resistant S. aureus through fish and highlights the potential influence of local fish handling and processing on consumer health worldwide. The introduction of periodic training in food safety and hygiene is essential to increase fish handlers' awareness of good hygienic practices in handling fish. These findings also enrich the ongoing debate about the risk of methicillin- and multidrug-resistant S. aureus as a foodborne pathogen compared with drug-susceptible S. aureus.

  4. Rapid identification and classification of Staphylococcus aureus by attenuated total reflectance fourier transform infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Staphylococcus aureus is an important bacterium that can cause serious infections in humans such as pneumonia and bacteremia. Rapid detection of this pathogen is crucial in food industries and clinical laboratories to control S. aureus food poisoning and human infections. In this study, fourier tran...

  5. Characterization and comparative analysis of a second thermonuclease in Staphylococcus aureus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Staphylococcal nuclease (here termed as NUC1) is considered an important virulence factor and a unique marker widely used in detection of Staphylococcus aureus. A novel functional thermostable nuclease (here termed as NUC2) in S. aureus was characterized after recombinant expression in Escherichia...

  6. 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

  7. Status of vaccine research and development of vaccines for Staphylococcus aureus.

    PubMed

    Giersing, Birgitte K; Dastgheyb, Sana S; Modjarrad, Kayvon; Moorthy, Vasee

    2016-06-03

    Staphylococcus aureus is a highly versatile gram positive bacterium that is resident as an asymptomatic colonizer on the skin and in the nasopharynx of approximately 30% of individuals. Nasopharyngeal colonization is a risk for acquiring S. aureus infections, which can cause a range of clinical symptoms that are commonly associated with skin and soft-tissue infections. The emergence of S. aureus strains that are highly resistant to antimicrobials has recently become a major public health concern. In low-income countries the incidence of S. aureus disease is highest in neonates and children up to one year of age and mortality rates are estimated to be up to 50%. In the United States, S. aureus infection accounts for approximately 300,000 hospitalizations per year. A vaccine against multi-drug resistant S. aureus, therefore, is urgently needed. Two vaccine candidates have previously been evaluated in late-stage clinical trials but have not demonstrated efficacy. At present, one vaccine candidate and two monoclonal antibody are undergoing clinical evaluation in target groups at high risk for S. aureus infection. This review provides an overview of current vaccine development efforts and presents the major technical and regulatory challenges to developing a licensed S. aureus vaccine.

  8. Subinhibitory concentrations of punicalagin reduces expression of virulence-related exoproteins by Staphylococcus aureus.

    PubMed

    Mun, Su-Hyun; Kong, Ryong; Seo, Yun-Soo; Zhou, Tian; Kang, Ok-Hwa; Shin, Dong-Won; Kwon, Dong-Yeul

    2016-11-01

    Staphylococcus aureus produces a number of virulence factors. The major virulence factors exhibited by S aureus include various antigens, enzymes, cytotoxins and exotoxins (e.g. hemolysins, enterotoxins and toxic shock syndrome toxin). In this report, we show the influence of punicalagin on the secretion of exoprotein from S aureus by western blotting, tumor necrosis factor (TNF) release assay and quantitative RT-PCR. When added to S aureus cultures at an OD600 of 0.9, graded subinhibitory concentrations of punicalagin reduced the production of α-toxin, SEA and SEB in methicillin-resistant Staphylococcus aureus in a dose-dependent manner. Consistently, punicalagin reduced TNF-inducing activity by S aureus culture supernatants. Here, the transcriptional level of agr (accessory gene regulator) in S aureus was inhibited by punicalagin, suggesting that the reduced transcription may affect the secretion of exotoxins. These findings suggest that the expression of α-toxin and enterotoxins in S aureus is sensitive to the action of punicalagin, which may be an advantageous candidate in the treatment of toxigenic staphylococcal disease.

  9. 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

  10. Mast cells are activated by Staphylococcus aureus in vitro but do not influence the outcome of intraperitoneal S. aureus infection in vivo.

    PubMed

    Rönnberg, Elin; Johnzon, Carl-Fredrik; Calounova, Gabriela; Garcia Faroldi, Gianni; Grujic, Mirjana; Hartmann, Karin; Roers, Axel; Guss, Bengt; Lundequist, Anders; Pejler, Gunnar

    2014-10-01

    Staphylococcus aureus is a major pathogen that can cause a broad spectrum of serious infections including skin infections, pneumonia and sepsis. Peritoneal mast cells have been implicated in the host response towards various bacterial insults and to provide mechanistic insight into the role of mast cells in intraperitoneal bacterial infection we here studied the global effects of S. aureus on mast cell gene expression. After co-culture of peritoneal mast cells with live S. aureus we found by gene array analysis that they up-regulate a number of genes. Many of these corresponded to pro-inflammatory cytokines, including interleukin-3, interleukin-13 and tumour necrosis factor-α. The cytokine induction in response to S. aureus was confirmed by ELISA. To study the role of peritoneal mast cells during in vivo infection with S. aureus we used newly developed Mcpt5-Cre(+) × R-DTA mice in which mast cell deficiency is independent of c-Kit. This is in contrast to previous studies in which an impact of mast cells on bacterial infection has been proposed based on the use of mice whose mast cell deficiency is a consequence of defective c-Kit signalling. Staphylococcus aureus was injected intraperitoneally into mast-cell-deficient Mcpt5-Cre(+) × R-DTA mice using littermate mast-cell-sufficient mice as controls. We did not observe any difference between mast-cell-deficient and control mice with regard to weight loss, bacterial clearance, inflammation or cytokine production. We conclude that, despite peritoneal mast cells being activated by S. aureus in vitro, they do not influence the in vivo manifestations of intraperitoneal S. aureus infection.

  11. A Meta-Analysis of the Global Prevalence Rates of Staphylococcus aureus and Methicillin-Resistant S. aureus Contamination of Different Raw Meat Products.

    PubMed

    Ou, Qianting; Peng, Yang; Lin, Dongxin; Bai, Chan; Zhang, Ting; Lin, Jialing; Ye, Xiaohua; Yao, Zhenjiang

    2017-03-30

    Previous research has indicated that raw meats are frequently contaminated with Staphylococcus aureus , but data regarding the pooled prevalence rates of S. aureus and methicillin-resistant S. aureus (MRSA) contamination in different types of raw meat products (beef, chicken, and pork) and across different periods, regions, and purchase locations remain inconsistent. We systematically searched the PubMed, EMBASE, Ovid, Web of Science, and HighWire databases to identify studies published up to June 2016. The STROBE guidelines were used to assess the quality of the 39 studies included in this meta-analysis. We observed no significant differences in the pooled prevalence rates of S. aureus and MRSA contamination identified in various raw meat products, with overall pooled prevalence rates of 29.2% (95% confidence interval [CI], 22.8 to 35.9%) and 3.2% (95% CI, 1.8 to 4.9%) identified for the two contaminants, respectively. In the subgroup analyses, the prevalence of S. aureus contamination in chicken products was highest in Asian studies and significantly decreased over time worldwide. In European studies, the prevalence rates of S. aureus contamination in chicken and pork products were lower than those reported on other continents. The pooled prevalence rates of S. aureus contamination in chicken and pork products and MRSA contamination in beef and pork products were significantly higher in samples collected from retail sources than in samples collected from slaughterhouses and processing plants. These results highlight the need for good hygiene during transportation to and manipulation at retail outlets to reduce the risk of transmission of S. aureus and MRSA from meat products to humans.

  12. Toll-Like Receptor 2 Stimulation of Osteoblasts Mediates Staphylococcus Aureus Induced Bone Resorption and Osteoclastogenesis through Enhanced RANKL

    PubMed Central

    Kassem, Ali; Lindholm, Catharina; Lerner, Ulf H

    2016-01-01

    Severe Staphylococcus aureus (S. aureus) infections pose an immense threat to population health and constitute a great burden for the health care worldwide. Inter alia, S. aureus septic arthritis is a disease with high mortality and morbidity caused by destruction of the infected joints and systemic bone loss, osteoporosis. Toll-Like receptors (TLRs) are innate immune cell receptors recognizing a variety of microbial molecules and structures. S. aureus recognition via TLR2 initiates a signaling cascade resulting in production of various cytokines, but the mechanisms by which S. aureus causes rapid and excessive bone loss are still unclear. We, therefore, investigated how S. aureus regulates periosteal/endosteal osteoclast formation and bone resorption. S. aureus stimulation of neonatal mouse parietal bone induced ex vivo bone resorption and osteoclastic gene expression. This effect was associated with increased mRNA and protein expression of receptor activator of NF-kB ligand (RANKL) without significant change in osteoprotegerin (OPG) expression. Bone resorption induced by S. aureus was abolished by OPG. S. aureus increased the expression of osteoclastogenic cytokines and prostaglandins in the parietal bones but the stimulatory effect of S. aureus on bone resorption and Tnfsf11 mRNA expression was independent of these cytokines and prostaglandins. Stimulation of isolated periosteal osteoblasts with S. aureus also resulted in increased expression of Tnfsf11 mRNA, an effect lost in osteoblasts from Tlr2 knockout mice. S. aureus stimulated osteoclastogenesis in isolated periosteal cells without affecting RANKL-stimulated resorption. In contrast, S. aureus inhibited RANKL-induced osteoclast formation in bone marrow macrophages. These data show that S. aureus enhances bone resorption and periosteal osteoclast formation by increasing osteoblast RANKL production through TLR2. Our study indicates the importance of using different in vitro approaches for studies of how S

  13. Clumping factor A, von Willebrand factor-binding protein and von Willebrand factor anchor Staphylococcus aureus to the vessel wall.

    PubMed

    Claes, J; Liesenborghs, L; Peetermans, M; Veloso, T R; Missiakas, D; Schneewind, O; Mancini, S; Entenza, J M; Hoylaerts, M F; Heying, R; Verhamme, P; Vanassche, T

    2017-02-09

    Essentials Staphylococcus aureus (S. aureus) binds to endothelium via von Willebrand factor (VWF). Secreted VWF-binding protein (vWbp) mediates S. aureus adhesion to VWF under shear stress. vWbp interacts with VWF and the Sortase A-dependent surface protein Clumping factor A (ClfA). VWF-vWbp-ClfA anchor S. aureus to vascular endothelium under shear stress.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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)

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Covering all the Bases: Preclinical Development of an Effective Staphylococcus aureus Vaccine

    PubMed Central

    Scully, Ingrid L.; Liberator, Paul A.; Jansen, Kathrin U.; Anderson, Annaliesa S.

    2014-01-01

    A key aspect of the pathogenesis of the Gram positive bacterium Staphylococcus aureus is its ability to rapidly adapt to the host environment during the course of an infection. To successfully establish infection, the organism deploys a variety of survival and immune evasion strategies, ranging from the acquisition of essential nutrients and expression of adhesins, which promote colonization and survival, to the elaboration of virulence factors such as capsule, which aids host immune evasion. The ability of S. aureus to deploy different virulence factors must be taken into account for S. aureus vaccine design. Here, we present a strategy for designing an effective vaccine against S. aureus disease by evaluating vaccine candidate performance in multiple in vivo models targeted to mimic aspects of human disease, and by co-development of functional in vitro immunoassays that measure the neutralization of relevant S. aureus virulence factors. PMID:24715889

  11. PBP 4 Mediates High-Level Resistance to New-Generation Cephalosporins in Staphylococcus aureus

    PubMed Central

    Chan, Liana C.; Gilbert, Aubre; Basuino, Li; da Costa, Thaina M.; Hamilton, Stephanie M.; dos Santos, Katia R.; Chambers, Henry F.

    2016-01-01

    Staphylococcus aureus is an important cause of both hospital- and community-associated methicillin-resistant S. aureus (MRSA) infections worldwide. β-Lactam antibiotics are the drugs of choice to treat S. aureus infections, but resistance to these and other antibiotics make treatment problematic. High-level β-lactam resistance of S. aureus has always been attributed to the horizontally acquired penicillin binding protein 2a (PBP 2a) encoded by the mecA gene. Here, we show that S. aureus can also express high-level resistance to β-lactams, including new-generation broad-spectrum cephalosporins that are active against methicillin-resistant strains, through an uncanonical core genome-encoded penicillin binding protein, PBP 4, a nonessential enzyme previously considered not to be important for staphylococcal β-lactam resistance. Our results show that PBP 4 can mediate high-level resistance to β-lactams. PMID:27067335

  12. Role of JAK-STAT signaling in maturation of phagosomes containing Staphylococcus aureus

    PubMed Central

    Zhu, Fei; Zhou, Yadong; Jiang, Chunxia; Zhang, Xiaobo

    2015-01-01

    Phagocytosis is a required mechanism for the defense against pathogens. Staphylococcus aureus, an important bacterial pathogen, can promptly escape from phagosomes and proliferate within the cytoplasm of host. However, the mechanism of phagocytosis against S. aureus has not been intensively investigated. In this study, the S. aureus was engulfed by macrophages (RAW264.7 cells) but not digested by the cells, suggesting that the phagosomes did not maturate in macrophages. Further investigation revealed that peptidoglycan (PG) induced the phagosome maturation of macrophages, resulting in the eradication of S. aureus. Genome-wide analysis and quantitative real-time PCR indicated that the JAK-STAT pathway was activated by PG during the phagosome maturation of macrophages against S. aureus. This finding presented that the PG-activated JAK-STAT pathway was required for phagosome maturation. Therefore, our study contributed evidence that revealed a novel aspect of PG-triggered JAK-STAT pathway in the phagosome maturation of macrophages. PMID:26442670

  13. Activation of heme biosynthesis by a small molecule that is toxic to fermenting Staphylococcus aureus

    PubMed Central

    Mike, Laura A.; Dutter, Brendan F.; Stauff, Devin L.; Moore, Jessica L.; Vitko, Nicholas P.; Aranmolate, Olusegun; Kehl-Fie, Thomas E.; Sullivan, Sarah; Reid, Paul R.; DuBois, Jennifer L.; Richardson, Anthony R.; Caprioli, Richard M.; Sulikowski, Gary A.; Skaar, Eric P.

    2013-01-01

    Staphylococcus aureus is a significant infectious threat to global public health. Acquisition or synthesis of heme is required for S. aureus to capture energy through respiration, but an excess of this critical cofactor is toxic to bacteria. S. aureus employs the heme sensor system (HssRS) to overcome heme toxicity; however, the mechanism of heme sensing is not defined. Here, we describe the identification of a small molecule activator of HssRS that induces endogenous heme biosynthesis by perturbing central metabolism. This molecule is toxic to fermenting S. aureus, including clinically relevant small colony variants. The utility of targeting fermenting bacteria is exemplified by the fact that this compound prevents the emergence of antibiotic resistance, enhances phagocyte killing, and reduces S. aureus pathogenesis. Not only is this small molecule a powerful tool for studying bacterial heme biosynthesis and central metabolism; it also establishes targeting of fermentation as a viable antibacterial strategy. PMID:23630262

  14. Metabolic glycoengineering of Staphylococcus aureus reduces its adherence to human T24 bladder carcinoma cells.

    PubMed

    Memmel, Elisabeth; Homann, Arne; Oelschlaeger, Tobias A; Seibel, Jürgen

    2013-08-25

    The Gram-positive bacterium Staphylococcus aureus is a human pathogen increasingly causing severe infections, especially in hospital environments. Moreover, strains which are resistant against various types of antibiotics are developing and spreading widely as in the case of the community-acquired MRSA (methicillin resistant S. aureus). In this study metabolic glycoengineering with N-azidoacetyl-glucosamine (GlcNAz) has been successfully applied to S. aureus for the first time. The following bioorthogonal Mendal-Sharpless-Huisgen click reaction between the azido-functionalized S. aureus cells and alkyne dyes enabled staining of these bacteria and reduced their adherence to human T24 bladder carcinoma cells by 48%. The results are of urgent interest to study S. aureus infections.

  15. First report of methicillin-resistant Staphylococcus aureus from cage-cultured tilapia (Oreochromis niloticus).

    PubMed

    Atyah, M A S; Zamri-Saad, M; Siti-Zahrah, A

    2010-08-26

    Swabs from the brain, eyes and kidneys of tilapia from 11 farms were collected for a period of 2 years. They were grown on blood agar before cultures of suspected Staphylococcus aureus were subjected to ABI STAPH Detection Kit and PCR for identification. They were then grown on oxacillin resistance screening agar base (ORSAB) and subjected to PCR using the MRSA 17 kb forward and reverse primers to identify the methicillin-resistant S. aureus (MRSA). A total of 559 isolates of Staphylococcus spp. were obtained, from which 198 (35%) isolates were identified as S. aureus. Of the 198 S. aureus isolated from tilapias, 98 (50%) were identified as methicillin-resistant S. aureus (MRSA). Since global spread of multi-drug-resistant bacteria has increased in the past decade, this new finding in fish should be of concern.

  16. Isorhamnetin Attenuates Staphylococcus aureus-Induced Lung Cell Injury by Inhibiting Alpha-Hemolysin Expression.

    PubMed

    Jiang, Lanxiang; Li, Hongen; Wang, Laiying; Song, Zexin; Shi, Lei; Li, Wenhua; Deng, Xuming; Wang, Jianfeng

    2016-03-01

    Staphylococcus aureus, like other gram-positive pathogens, has evolved a large repertoire of virulence factors as a powerful weapon to subvert the host immune system, among which alpha-hemolysin (Hla), a secreted pore-forming cytotoxin, plays a preeminent role. We observed a concentration-dependent reduction in Hla production by S. aureus in the presence of sub-inhibitory concentrations of isorhamnetin, a flavonoid from the fruits of Hippophae rhamnoides L., which has little antibacterial activity. We further evaluate the effect of isorhamnetin on the transcription of the Hla-encoding gene hla and RNAIII, an effector molecule in the agr system. Isorhamnetin significantly down-regulated RNAIII expression and subsequently inhibited hla transcription. In a co-culture of S. aureus and lung cells, topical isorhamnetin treatment protected against S. aureus-induced cell injury. Isorhamnetin may represent a leading compound for the development of anti-virulence drugs against S. aureus infections.

  17. Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus clonal complexes in bulk tank milk from dairy cattle herds in Lombardy Region (Northern Italy).

    PubMed

    Cortimiglia, C; Luini, M; Bianchini, V; Marzagalli, L; Vezzoli, F; Avisani, D; Bertoletti, M; Ianzano, A; Franco, A; Battisti, A

    2016-10-01

    Staphylococcus aureus is the most important causative agent of subclinical mastitis in cattle resulting in reduced milk production and quality. Methicillin-resistant S. aureus (MRSA) strains has a clear zoonotic relevance, especially in the case of occupational exposure. The aim of the study was to evaluate the prevalence of S. aureus and MRSA in bulk tank milk (BTM) from dairy cattle herds in the Lombardy Region (Northern Italy) and to identify the main MRSA circulating genotypes. MRSA strains were characterized by susceptibility testing, multi-locus sequence typing (MLST), spa typing and SCCmec typing. A total 844 BTM samples were analysed and S. aureus and MRSA were detected in 47·2% and 3·8% of dairy herds, respectively. MLST showed that the majority (28/32) of isolates belonged to the typical livestock-associated lineages: ST398, ST97 and ST1. Interestingly, in this study we report for the first time the new ST3211, a single locus variant of ST(CC)22, with the newly described 462 aroE allele. Our study indicates high diffusion of S. aureus mastitis and low, but not negligible, prevalence of MRSA in the considered area, suggesting the need for planning specific control programmes for bovine mastitis caused by S. aureus, especially when MRSA is implicated.

  18. Mortality among recipients of the Merck V710 Staphylococcus aureus vaccine after postoperative S. aureus infections: an analysis of possible contributing host factors.

    PubMed

    McNeely, Tessie B; Shah, Najaf A; Fridman, Arthur; Joshi, Amita; Hartzel, Jonathan S; Keshari, Ravi S; Lupu, Florea; DiNubile, Mark J

    2014-01-01

    In a blinded randomized trial, preoperative receipt of the Merck V710 Staphylococcus aureus vaccine was associated with a higher mortality rate than placebo in patients who later developed postoperative S. aureus infections. Of the tested patients, all 12 V710 recipients (but only 1 of 13 placebo recipients) with undetectable serum IL2 levels prior to vaccination and surgery died after postoperative S. aureus infection. The coincidence of 3 factors (low prevaccination IL-2 levels, receipt of V710, and postoperative S. aureus infection) appeared to substantially increase mortality in our study population after major cardiothoracic surgery. Furthermore, 9 of the 10 V710 recipients with undetectable preoperative IL17a levels and postoperative S. aureus infections died. Although the current study is hypothesis-generating and the exact pathophysiology remains speculative, these findings raise concern that immune predispositions may adversely impact the safety and efficacy of staphylococcal vaccines actively under development. The potential benefits of an effective vaccine against S. aureus justify continued but cautious pursuit of this elusive goal.

  19. The herbal-derived honokiol and magnolol enhances immune response to infection with methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA).

    PubMed

    Choi, Eun-Jin; Kim, Hyung-Ip; Kim, Ji-Ae; Jun, Soo Youn; Kang, Sang Hyeon; Park, Dong June; Son, Seok-Jun; Kim, Younghoon; Shin, Ok Sarah

    2015-05-01

    The emergence of antibiotic resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) reminds us an urgent need to develop a new immune-modulating agent for preventing S. aureus infection. In this study, we found that herbal medicines, honokiol and magnolol, caused a significant cellular immune modulatory effect during S. aureus infection. In mouse macrophages, these compounds drove upregulation of an antioxidant effect in response to S. aureus, resulting in a dampened total cellular reactive oxygen species (ROS) production and decreased production of inflammatory cytokines/chemokines, whereas honokiol induced increased types I and III interferon messenger RNA (mRNA) expression levels in response to MSSA infection. Moreover, the internalization of S. aureus by human alveolar epithelial cells was inhibited by these compounds. Furthermore, honokiol and magnolol treatment promoted a delay in killing during MSSA infection in Caenorhabditis elegans, suggesting antimicrobial function in vivo. In conclusion, honokiol and magnolol may be considered as attractive immune-modulating treatment for S. aureus infection.

  20. Predictors of community-associated Staphylococcus aureus, methicillin-resistant and methicillin-susceptible Staphylococcus aureus skin and soft tissue infections in primary-care settings.

    PubMed

    Lee, G C; Hall, R G; Boyd, N K; Dallas, S D; DU, L C; Treviño, L B; Retzloff, C; Treviño, S B; Lawson, K A; Wilson, J P; Olsen, R J; Wang, Y; Frei, C R

    2016-11-01

    Skin and soft tissue infections (SSTIs) due to Staphylococcus aureus have become increasingly common in the outpatient setting; however, risk factors for differentiating methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) SSTIs are needed to better inform antibiotic treatment decisions. We performed a case-case-control study within 14 primary-care clinics in South Texas from 2007 to 2015. Overall, 325 patients [S. aureus SSTI cases (case group 1, n = 175); MRSA SSTI cases (case group 2, n = 115); MSSA SSTI cases (case group 3, n = 60); uninfected control group (control, n = 150)] were evaluated. Each case group was compared to the control group, and then qualitatively contrasted to identify unique risk factors associated with S. aureus, MRSA, and MSSA SSTIs. Overall, prior SSTIs [adjusted odds ratio (aOR) 7·60, 95% confidence interval (CI) 3·31-17·45], male gender (aOR 1·74, 95% CI 1·06-2·85), and absence of healthcare occupation status (aOR 0·14, 95% CI 0·03-0·68) were independently associated with S. aureus SSTIs. The only unique risk factor for community-associated (CA)-MRSA SSTIs was a high body weight (⩾110 kg) (aOR 2·03, 95% CI 1·01-4·09).

  1. Bactericidal activity of the food color additive Phloxine B against Staphylococcus aureus and other food borne microbial pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spread of antibiotic resistance among Staphylococcus aureus strains requires the development of new anti S. aureus agents. The objective of this study was evaluating the antimicrobial activity of the food color additive Phloxine B against S. aureus and other food microbial pathogens. Our result ...

  2. Nasal Carriage of Staphylococcus aureus: Frequency and Antibiotic Resistance in Healthy Ruminants

    PubMed Central

    Rahimi, Heidar; Dastmalchi Saei, Habib; Ahmadi, Malahat

    2015-01-01

    Background: Staphylococcus aureus is a significant pathogen that can colonize the nares of different animals, causing a wide range of infections in various hosts. Objectives: We intended to determine the prevalence of S. aureus in the nasal cavity of healthy ruminants and also to investigate the presence of antibiotic resistance genes. Materials and Methods: In the present study, healthy cattle (n = 79), sheep (n = 78) and goats (n = 44) were screened for nasal carriage of S. aureus by the Polymerase Chain Reaction (PCR). Staphylococcus aureus isolates were further assessed for the presence of blaZ (encoding penicillin resistance), mecA (encoding methicillin resistance), tetK and tetM (encoding tetracycline resistance), and ermA and ermC (encoding macrolide-lincosamide-streptogramin B resistance) genes. Results: The proportion of S. aureus-positive nasal swabs from cattle, sheep and goats were four (5.06%), 11 (14.1%) and 11 isolates (25%), respectively. The blaZ gene was detected in 20 out of 26 S. aureus isolates (76.9%), including four cattle (100%), nine sheep (81.8%) and seven goats (63.6%). Two of the four cattle isolates possessing the blaZ gene also had the tetK gene. Of the nine sheep isolates harboring the blaZ gene, one possessed the mecA and tetK genes together. Of the seven goat isolates with blaZ gene, one harbored the tetM gene. None of the S. aureus isolates were positive for the ermA and ermC genes. Conclusions: In contrast to cattle, S. aureus is frequently present in the nose of sheep and goats, which may represent the primary reservoir of S. aureus in small ruminant flocks. This study also showed that nasal isolates of S. aureus from healthy ruminants might be a potential reservoir of antimicrobial-resistance. PMID:26568802

  3. Tannic acid inhibits Staphylococcus aureus surface colonization in an IsaA-dependent manner.

    PubMed

    Payne, David E; Martin, Nicholas R; Parzych, Katherine R; Rickard, Alex H; Underwood, Adam; Boles, Blaise R

    2013-02-01

    Staphylococcus aureus is a human commensal and pathogen that is capable of forming biofilms on a variety of host tissues and implanted medical devices. Biofilm-associated infections resist antimicrobial chemotherapy and attack from the host immune system, making these infections particularly difficult to treat. In order to gain insight into environmental conditions that influence S. aureus biofilm development, we screened a library of small molecules for the ability to inhibit S. aureus biofilm formation. This led to the finding that the polyphenolic compound tannic acid inhibits S. aureus biofilm formation in multiple biofilm models without inhibiting bacterial growth. We present evidence that tannic acid inhibits S. aureus biofilm formation via a mechanism dependent upon the putative transglycosylase IsaA. Tannic acid did not inhibit biofilm formation of an isaA mutant. Overexpression of wild-type IsaA inhibited biofilm formation, whereas overexpression of a catalytically dead IsaA had no effect. Tannin-containing drinks like tea have been found to reduce methicillin-resistant S. aureus nasal colonization. We found that black tea inhibited S. aureus biofilm development and that an isaA mutant resisted this inhibition. Antibiofilm activity was eliminated from tea when milk was added to precipitate the tannic acid. Finally, we developed a rodent model for S. aureus throat colonization and found that tea consumption reduced S. aureus throat colonization via an isaA-dependent mechanism. These findings provide insight into a molecular mechanism by which commonly consumed polyphenolic compounds, such as tannins, influence S. aureus surface colonization.

  4. Tannic Acid Inhibits Staphylococcus aureus Surface Colonization in an IsaA-Dependent Manner

    PubMed Central

    Payne, David E.; Martin, Nicholas R.; Parzych, Katherine R.; Rickard, Alex H.; Underwood, Adam

    2013-01-01

    Staphylococcus aureus is a human commensal and pathogen that is capable of forming biofilms on a variety of host tissues and implanted medical devices. Biofilm-associated infections resist antimicrobial chemotherapy and attack from the host immune system, making these infections particularly difficult to treat. In order to gain insight into environmental conditions that influence S. aureus biofilm development, we screened a library of small molecules for the ability to inhibit S. aureus biofilm formation. This led to the finding that the polyphenolic compound tannic acid inhibits S. aureus biofilm formation in multiple biofilm models without inhibiting bacterial growth. We present evidence that tannic acid inhibits S. aureus biofilm formation via a mechanism dependent upon the putative transglycosylase IsaA. Tannic acid did not inhibit biofilm formation of an isaA mutant. Overexpression of wild-type IsaA inhibited biofilm formation, whereas overexpression of a catalytically dead IsaA had no effect. Tannin-containing drinks like tea have been found to reduce methicillin-resistant S. aureus nasal colonization. We found that black tea inhibited S. aureus biofilm development and that an isaA mutant resisted this inhibition. Antibiofilm activity was eliminated from tea when milk was added to precipitate the tannic acid. Finally, we developed a rodent model for S. aureus throat colonization and found that tea consumption reduced S. aureus throat colonization via an isaA-dependent mechanism. These findings provide insight into a molecular mechanism by which commonly consumed polyphenolic compounds, such as tannins, influence S. aureus surface colonization. PMID:23208606

  5. Dissemination of panton-valentine leukocidin-positive methicillin-resistant Staphylococcus aureus in Okinawa, Japan.

    PubMed

    Mine, Yoshiko; Nakasone, Isamu; Yamamoto, Yuichi; Utani, Atsushi; Yamane, Nobuhisa; Uezato, Hiroshi; Takahashi, Kenzo

    2013-01-01

    Panton-Valentine leukocidin (PVL) is a pore-forming cytotoxin that is produced by Staphylococcus aureus closely associated with skin and soft-tissue infections (SSTI). PVL-positive S. aureus strains have been identified worldwide, including in the USA; however, few studies have reported the presence of these strains in Japan. In this study, we prospectively investigated the prevalence of PVL in S. aureus strains from outpatients presenting with SSTI in Okinawa and characterized the PVL-positive S. aureus strains by polymerase chain reaction (PCR) and multilocus sequence typing (MLST). From 2008-2010, 499 clinical samples were obtained from 497 people. S. aureus was identified in 274 samples, and 36% (99 of 274) were methicillin-resistant S. aureus (MRSA). Seventeen (6.2%) PVL-positive S. aureus strains were detected by PCR, and 12 of the 17 PVL-positive strains were MRSA. Most PVL-positive S. aureus caused furuncles or carbuncles. Nine of the 17 PVL-positive isolates had an ST8 MRSA genotype and most harbored SCCmec type IVa and the arcA gene of the arginine catabolic mobile element, which is identical to the USA300 clone prevalent in the USA. PVL-positive S. aureus strains were more likely to be resistant to erythromycin (65%) and levofloxacin (53%). PVL-positive S. aureus strains have emerged and are spreading as a causative pathogen for SSTI in Okinawa.

  6. Staphylococcus aureus Nasal Carriage among Beefpacking Workers in a Midwestern United States Slaughterhouse

    PubMed Central

    Leibler, Jessica H.; Jordan, Jeanne A.; Brownstein, Kirsten; Lander, Lina; Price, Lance B.; Perry, Melissa J.

    2016-01-01

    Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureus carriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureus exposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of S. aureus nasal colonization, specifically the absence of the scn gene to identify putative association with livestock, antibiotic susceptibility, presence of Panton-Valentin leukocidin (PVL) genes lukS-PV and lukF-PV, and spa type. Overall prevalence of S. aureus nasal carriage was 27.0%. No workers carried livestock-associated MRSA. Methicillin-sensitive S. aureus isolates (MSSA) recovered from five workers (3.6%) lacked the scn gene and were considered putative livestock-associated S. aureus (pLA-SA). Among pLA-SA isolates, spa types t338, t748, t1476 and t2379 were identified. To our knowledge, these spa types have not previously been identified as associated with livestock. Prevalence of human-adapted MRSA carriage in workers was 3.6%. MRSA isolates were identified as spa types t002, t008 and t024, and four of five MRSA isolates were PVL-positive. To date, this is the first study to indicate that industrial beefpacking workers in the United States may be exposed to livestock-associated S. aureus, notably MSSA, and to spa types not previously identified in livestock and livestock workers. Occupational exposure to livestock-associated S. aureus in the beef production chain requires further epidemiologic investigation. PMID:26866374

  7. Factors Associated with Worse Lung Function in Cystic Fibrosis Patients with Persistent Staphylococcus aureus

    PubMed Central

    den Reijer, Martijn; Wiedemann, Bärbel; Tümmler, Burkhard; Ellemunter, Helmut; Dübbers, Angelika; Küster, Peter; Ballmann, Manfred; Koerner-Rettberg, Cordula; Große-Onnebrink, Jörg; Heuer, Eberhardt; Sextro, Wolfgang; Mainz, Jochen G.; Hammermann, Jutta; Riethmüller, Joachim; Graepler-Mainka, Ute; Staab, Doris; Wollschläger, Bettina; Szczepanski, Rüdiger; Schuster, Antje; Tegtmeyer, Friedrich-Karl; Sutharsan, Sivagurunathan; Wald, Alexandra; Nofer, Jerzy-Roch; van Wamel, Willem; Becker, Karsten; Peters, Georg

    2016-01-01

    Background Staphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads. Methods Therefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors. Results 195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001). Patients with exacerbations (n = 60), S. aureus small-colony variants (SCVs, n = 84) and co-infection with Stenotrophomonas maltophilia (n = 44) had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103). Patients with SCVs were older (p = 0.0066) and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078). IL-6 levels positively correlated with decreased lung function (p<0.001), S. aureus density in sputa (p = 0.0016), SCVs (p = 0.0209), exacerbations (p = 0.0041) and co-infections with S. maltophilia (p = 0.0195) or A. fumigatus (p = 0.0496). Conclusions In CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia. Trial Registration ClinicalTrials.gov NCT

  8. Staphylococcus aureus Nasal Carriage among Beefpacking Workers in a Midwestern United States Slaughterhouse.

    PubMed

    Leibler, Jessica H; Jordan, Jeanne A; Brownstein, Kirsten; Lander, Lina; Price, Lance B; Perry, Melissa J

    2016-01-01

    Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureus carriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureus exposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of S. aureus nasal colonization, specifically the absence of the scn gene to identify putative association with livestock, antibiotic susceptibility, presence of Panton-Valentin leukocidin (PVL) genes lukS-PV and lukF-PV, and spa type. Overall prevalence of S. aureus nasal carriage was 27.0%. No workers carried livestock-associated MRSA. Methicillin-sensitive S. aureus isolates (MSSA) recovered from five workers (3.6%) lacked the scn gene and were considered putative livestock-associated S. aureus (pLA-SA). Among pLA-SA isolates, spa types t338, t748, t1476 and t2379 were identified. To our knowledge, these spa types have not previously been identified as associated with livestock. Prevalence of human-adapted MRSA carriage in workers was 3.6%. MRSA isolates were identified as spa types t002, t008 and t024, and four of five MRSA isolates were PVL-positive. To date, this is the first study to indicate that industrial beefpacking workers in the United States may be exposed to livestock-associated S. aureus, notably MSSA, and to spa types not previously identified in livestock and livestock workers. Occupational exposure to livestock-associated S. aureus in the beef production chain requires further epidemiologic investigation.

  9. Evaluation of Approaches to Monitor Staphylococcus aureus Virulence Factor Expression during Human Disease

    PubMed Central

    Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C. Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P. H.; Savelkoul, Paul H. M.; Jansen, Kathrin U.; Anderson, Annaliesa S.; Kluytmans, Jan

    2015-01-01

    Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27) or bloodstream (24) infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR) analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine. PMID:25719409

  10. Temperature-dependent control of Staphylococcus aureus biofilms and virulence by thermoresponsive oligo(N-vinylcaprolactam).

    PubMed

    Lee, Jin-Hyung; Kim, Yong-Guy; Lee, Kayeon; Kim, Seong-Cheol; Lee, Jintae

    2015-04-01

    Bacterial biofilms are associated with persistent infections because they are highly tolerant of antimicrobial agents, and in the case of Staphylococcus aureus, which is a leading cause of nosocomial infections because of its resistance to diverse antibiotics, biofilm formation is a known mechanism of drug resistance. In the present study, we investigated the ability of thermoresponsive oligo (N-vinylcaprolactam) (OVCL) to control biofilm formation by and the virulence of S. aureus. One synthetic and four commercial OVCLs (MW ≤ 240,000) at 50 µg/mL were found to increase S. aureus biofilm formation 7-fold at 25 °C, but to markedly inhibit S. aureus biofilm formation at 37 °C. Confocal and scanning electron microscopy confirmed the temperature-dependent effect of OVCL on S. aureus biofilms. It was found that the addition of OVCL to S. aureus culture caused cells to become dramatically more hydrophilic at 37 °C, which partially supports the biofilm reduction. Also, transcriptional analysis showed that OVCL temperature-dependently regulated biofilm-related genes (aur, agrA, and icaA) in S. aureus. In addition, it was found surface coatings containing OVCL effectively controlled S. aureus biofilm formation on solid glass surfaces. Furthermore, OVCL inhibited the hemolysis of human red blood cells by S. aureus at 37 °C and attenuated S. aureus virulence in the nematode Caenorhabditis elegans. These results suggest that OVCL has potential use for controlling bacterial biofilm formation and virulence.

  11. Antimicrobial Resistance, Biofilm Formation and mecA Characterization of Methicillin-Susceptible S. aureus and Non-S. aureus of Beef Meat Origin in Egypt.

    PubMed

    Osman, Kamelia M; Amer, Aziza M; Badr, Jihan M; Helmy, Nashwa M; Elhelw, Rehab A; Orabi, Ahmed; Bakry, Magdy; Saad, Aalaa S A

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible non-S. aureus (MS-NSA), and methicillin-resistant non-S. aureus (MR-NSA) were not investigated. Therefore, we persued to determine the diversity in their phenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterization in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus) were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB, and grlA). Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%), while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%), S. intermedius (33.3%), S. schleiferi subsp. coagulans (100%), and S. lentus (100%) were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius, and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7%) carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus. Although, global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates, that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which

  12. Antimicrobial Resistance, Biofilm Formation and mecA Characterization of Methicillin-Susceptible S. aureus and Non-S. aureus of Beef Meat Origin in Egypt

    PubMed Central

    Osman, Kamelia M.; Amer, Aziza M.; Badr, Jihan M.; Helmy, Nashwa M.; Elhelw, Rehab A.; Orabi, Ahmed; Bakry, Magdy; Saad, Aalaa S. A.

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible non-S. aureus (MS-NSA), and methicillin-resistant non-S. aureus (MR-NSA) were not investigated. Therefore, we persued to determine the diversity in their phenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterization in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus) were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB, and grlA). Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%), while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%), S. intermedius (33.3%), S. schleiferi subsp. coagulans (100%), and S. lentus (100%) were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius, and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7%) carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus. Although, global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates, that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which

  13. Spa Typing of Staphylococcus aureus Strains Isolated From Clinical Specimens of Patients With Nosocomial Infections in Tehran, Iran

    PubMed Central

    Goudarzi, Mehdi; Fazeli, Maryam; Goudarzi, Hossein; Azad, Mehdi; Seyedjavadi, Sima Sadat

    2016-01-01

    Background The incidence of nosocomial Staphylococcus aureus infection is increasing annually and becoming a true global challenge. The pattern of Staphylococcus aureus protein A (spa) types in different geographic regions is diverse. Objectives This study determined the prevalence of methicillin-resistant S. aureus and different spa types in S. aureus clinical isolates. Materials and Methods During a six-month period, 90 S. aureus isolates were recovered from 320 clinical specimens. The in vitro susceptibility of various S. aureus isolates to 16 antibiotic discs was assessed using the Kirby-Bauer disk diffusion method. Molecular typing was carried out with S. aureus protein A typing via polymerase chain reaction. Results The frequency of methicillin-resistant S. aureus in our study was 88.9%. Twenty-three (25.5%) isolates were positive for panton-valentine leukocidin encoding genes. S. aureus presented a high resistance rate to ampicillin (100%) and penicillin (100%). No resistance was observed to vancomycin, teicoplanin, or linezolid. The rates of resistance to the majority of antibiotics tested varied between 23.3% and 82.2%. The rate of multidrug resistance among these clinical isolates was 93.3%. The 90 S. aureus isolates were classified into five S. aureus protein A types: t037 (33.3%), t030 (22.2%), t790 (16.7%), t969 (11.1%), and t044 (7.7%). Eight (8.9%) isolates were not typable using the S. aureus protein A typing method. Conclusions We report a high methicillin-resistant S. aureus rate in our hospital. Additionally, t030 and t037 were the predominant spa-types among hospital-associated S. aureus. Our findings emphasize the need for continuous surveillance to prevent the dissemination of multidrug resistance among different S. aureus protein A types in Iran. PMID:27679706

  14. Evaluation of CHROMagar Staph. aureus, a New Chromogenic Medium, for Isolation and Presumptive Identification of Staphylococcus aureus from Human Clinical Specimens

    PubMed Central

    Gaillot, Olivier; Wetsch, Muriel; Fortineau, Nicolas; Berche, Patrick

    2000-01-01

    CHROMagar Staph. aureus (CSA) is a new chromogenic medium for presumptive identification of Staphylococcus aureus as mauve colonies after 24 h of incubation. We conducted a preliminary study with 100 S. aureus and 45 coagulase-negative Staphylococcus (CoNS) stock isolates plated on CSA. All S. aureus isolates yielded mauve colonies after 24 h of incubation at 37°C, while CoNS isolates grew as blue, white, or beige colonies. Culture on CSA was then prospectively compared to a conventional laboratory method, i.e., culture on 5% horse blood agar (HBA), catalase test, and latex agglutination test (HBA-catalase-latex), for isolation and presumptive identification of S. aureus from 2,000 consecutive clinical samples. Among the 310 S. aureus isolates recovered by at least one of the two methods, 296 grew as typical mauve colonies on CSA, while only 254 yielded catalase-positive, latex-positive colonies on HBA. The sensitivity of CSA was significantly higher than that of the conventional method (95.5 and 81.9%, respectively; P < 0.001) and allowed the recovery of important clinical isolates that were undetected on blood agar. The specificities of the two methods were not significantly different, although that of CSA was slightly higher (99.4% versus 98.9% for HBA-catalase-latex; P = 0.08). On the basis of its excellent sensitivity and specificity, ease of identification of positive colonies, and absence of complementary testing, CSA can be recommended as a routine plating medium for presumptive identification of S. aureus in clinical specimens. PMID:10747148

  15. Antibacterial Activity of Mulinum spinosum Extracts against Slime-Producing Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus Isolated from Nasal Carriers

    PubMed Central

    Daniela, Echenique; Alejandra, Chiaramello; Pedro, Rossomando; Claudia, Mattana; Lucía, Alcaráz; Carlos, Tonn; Analía, Laciar; Sara, Satorres

    2014-01-01

    Nasal carriers of Staphylococcus aureus are important reservoirs with risk of developing endogenous infections or transmitting infections to susceptible individuals. Methicillin-resistant S. aureus (MRSA) are associated with higher rates of treatment failure. Some strains of S. aureus produce slime which is believed to make the microorganisms more resistant to antibiotics and host defenses. The antibacterial activity of ethyl acetate : n-hexane (EtOAc : HEX) extracts of Mulinum spinosum (5 : 95% EtOAc : HEX, 50 : 50% EtOAc : HEX, 70 : 30% EtOAc : HEX and mix 20 : 80/30 : 70% EtOAc : HEX, 50 : 50/70 : 30/100 : 0% EtOAc : HEX) were assayed against 3 slime-producing S. aureus strains and 2 MRSA strains isolated from nasal carriers. S. aureus ATCC 35556 slime-producing strain and MRSA ATCC 43300 strain were used as controls. The extracts were prepared using flash chromatography. M. spinosum 5 : 95% AcOEt : HEX showed antibacterial effect against all slime-producing strains (MIC: 500 µg/mL) and the highest activity against MRSA strains (MIC: 500 to 1000 µg/mL). All M. spinosum extracts assayed were active against slime-producing S. aureus and MRSA at doses between 500 and 4000 µg/mL. Both, slime-producing S. aureus and MRSA are highly contagious and hardly eradicated by antibiotic therapies. So, there is an increasing need to find new substances with the ability to inhibit these strains. PMID:25530997

  16. Active immunization with an octa-valent Staphylococcus aureus antigen mixture in models of S. aureus bacteremia and skin infection in mice.

    PubMed

    van den Berg, Sanne; Koedijk, Dennis G A M; Back, Jaap Willem; Neef, Jolanda; Dreisbach, Annette; van Dijl, Jan Maarten; Bakker-Woudenberg, Irma A J M; Buist, Girbe

    2015-01-01

    Proteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl) and four phenol-soluble modulins α (PSMα) are invariantly produced by this pathogen. Therefore the present study was aimed at investigating whether these proteins can be used for active immunization against S. aureus infection in mouse models of bacteremia and skin infection. To this end, recombinant His-tagged fusions of IsaA, LytM, Nuc and pro-Atl were isolated from Lactococcus lactis or Escherichia coli, while the PSMα1-4 peptides were chemically synthesized. Importantly, patients colonized by S. aureus showed significant immunoglobulin G (IgG) responses against all eight antigens. BALB/cBYJ mice were immunized subcutaneously with a mixture of the antigens at day one (5 μg each), and boosted twice (25 μg of each antigen) with 28 days interval. This resulted in high IgG responses against all antigens although the response against pro-Atl was around one log lower compared to the other antigens. Compared to placebo-immunized mice, immunization with the octa-valent antigen mixture did not reduce the S. aureus isolate P load in blood, lungs, spleen, liver, and kidneys in a bacteremia model in which the animals were challenged for 14 days with a primary load of 3 × 10(5) CFU. Discomfort scores and animal survival rates over 14 days did not differ between immunized mice and placebo-immunized mice upon bacteremia with S. aureus USA300 (6 × 10(5) CFU). In addition, this immunization did not reduce the S. aureus isolate P load in mice with skin infection. These results show that the target antigens are immunogenic in both humans and mice, but in the used animal models do not result in protection against S. aureus infection.

  17. Short communication: Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus in bulk tank milk from dairy goat farms in Northern Italy.

    PubMed

    Cortimiglia, C; Bianchini, V; Franco, A; Caprioli, A; Battisti, A; Colombo, L; Stradiotto, K; Vezzoli, F; Luini, M

    2015-04-01

    Staphylococcus aureus is regarded as a leading cause of mastitis in goats. However, few data are available on the presence of methicillin-resistant S. aureus (MRSA) in this species. The aim of this study was to assess the prevalence of S. aureus and MRSA in bulk tank milk samples from dairy goat farms in Northern Italy. Eighty-five out of 197 samples (43.1%) tested positive for S. aureus with counts ranging from 10 to more than 1.5 × 10(4) cfu/mL. The MRSA was screened by both direct plating followed by a disk diffusion test to evaluate methicillin resistance and a selective enrichment method. Methicillin-resistance was confirmed by mecA-specific PCR. Methicillin-resistant S. aureus was identified in 4 samples (2.0%) and multilocus sequence typing (MLST) showed the presence of livestock-associated MRSA belonging to lineages ST398 (n = 3) and ST1 (n = 1). In one case we demonstrated that the same MRSA strain was able to persist over time on the farm, being isolated from both bulk tank milk and the udder of 3 goats 1 yr after the first isolation. The high prevalence of S. aureus-positive herds detected in this study and the presence of MRSA strains belonging to livestock-associated genotypes is of concern, and represents a novel finding in the Italian dairy goat production system. The application of stringent measures for the control of S. aureus mastitis at the farm level seems appropriate to reduce the economic losses, and to minimize the risk of foodborne illness and the transmission of MRSA to humans by occupational exposure.

  18. Post-invasion events after infection with Staphylococcus aureus are strongly dependent on both the host cell type and the infecting S. aureus strain.

    PubMed

    Strobel, M; Pförtner, H; Tuchscherr, L; Völker, U; Schmidt, F; Kramko, N; Schnittler, H-J; Fraunholz, M J; Löffler, B; Peters, G; Niemann, S

    2016-09-01

    Host cell invasion is a major feature of Staphylococcus aureus and contributes to infection development. The intracellular metabolically active bacteria can induce host cell activation and death but they can also persist for long time periods. In this study a comparative analysis was performed of different well-characterized S. aureus strains in their interaction with a variety of host cell types. Staphylococcus aureus (strains 6850, USA300, LS1, SH1000, Cowan1) invasion was compared in different human cell types (epithelial and endothelial cells, keratinocytes, fibroblasts, osteoblasts). The number of intracellular bacteria was determined, cell inflammation was investigated, as well as cell death and phagosomal escape of bacteria. To explain strain-dependent differences in the secretome, a proteomic approach was used. Barrier cells took up high amounts of bacteria and were killed by aggressive strains. These strains expressed high levels of toxins, and possessed the ability to escape from phagolysosomes. Osteoblasts and keratinocytes ingested less bacteria, and were not killed, even though the primary osteoblasts were strongly activated by S. aureus. In all cell types S. aureus was able to persist. Strong differences in uptake, cytotoxicity, and inflammatory response were observed between primary cells and their corresponding cell lines, demonstrating that cell lines reflect only partially the functions and physiology of primary cells. This study provides a contribution for a better understanding of the pathomechanisms of S. aureus infections. The proteomic data provide important basic knowledge on strains commonly used in the analysis of S. aureus-host cell interaction.

  19. Genetic diversity of multidrug resistant Staphylococcus aureus isolated from clinical and non clinical samples in Egypt.

    PubMed

    Bendary, M M; Solyman, S M; Azab, M M; Mahmoud, N F; Hanora, A M

    2016-08-31

    In recent years, the increasing incidence of diseases caused by Staphylococcus aureus (S. aureus) has been noted in the university hospitals of El-Sharkia and Assuit governorates - Egypt. Therefore, we studied the genetic relatedness of multidrug resistant S. aureus isolates from different sources in the above mentioned governorates. One hundred and fifty six S. aureus isolates were divided into 5 different groups, 1 non clinical isolates from different food products and 4 different clinical isolates of human and animal sources in the 2 different governorates. Epidemiological characteristics of 156 S. aureus isolates were determined by phenotypic methods including quantitative antibiogram typing and biofilm production. Genetic typing of 35 multidrug resistant (MDR) isolates (7 from each group) based on 16S rRNA gene sequence, virulence and antimicrobial resistance gene profiles was done. The genetic relatedness of the highest virulent strain from each group was detected based on different single locus sequence typing and multi-locus sequence typing (MLST). S. aureus strains isolated from different sources and geographical areas showed high diversity. The genetic typing revealed different sequence types and different sequences of coa and spa genes. S. aureus isolates were found highly diverse in Egypt.

  20. 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.

  1. Phevalin (aureusimine B) production by Staphylococcus aureus biofilm and impacts on human keratinocyte gene expression.

    PubMed

    Secor, Patrick R; Jennings, Laura K; James, Garth A; Kirker, Kelly R; Pulcini, Elinor Delancey; McInnerney, Kate; Gerlach, Robin; Livinghouse, Tom; Hilmer, Jonathan K; Bothner, Brian; Fleckman, Philip; Olerud, John E; Stewart, Philip S

    2012-01-01

    Staphylococcus aureus biofilms are associated with chronic skin infections and are orders of magnitude more resistant to antimicrobials and host responses. S. aureus contains conserved nonribosomal peptide synthetases that produce the cyclic dipeptides tyrvalin and phevalin (aureusimine A and B, respectively). The biological function of these compounds has been speculated to be involved in virulence factor gene expression in S. aureus, protease inhibition in eukaryotic cells, and interspecies bacterial communication. However, the exact biological role of these compounds is unknown. Here, we report that S. aureus biofilms produce greater amounts of phevalin than their planktonic counterparts. Phevalin had no obvious impact on the extracellular metabolome of S. aureus as measured by high-performance liquid chromatography-mass spectrometry and nuclear magnetic resonance. When administered to human keratinocytes, phevalin had a modest effect on gene expression. However, conditioned medium from S. aureus spiked with phevalin amplified differences in keratinocyte gene expression compared to conditioned medium alone. Phevalin may be exploited as potential biomarker and/or therapeutic target for chronic, S. aureus biofilm-based infections.

  2. Staphylococcus aureus exploits epidermal barrier defects in atopic dermatitis to trigger cytokine expression

    PubMed Central

    Nakatsuji, Teruaki; Chen, Tiffany H.; Two, Aimee M.; Chun, Kimberly A.; Narala, Saisindhu; Geha, Raif S.; Hata, Tissa R.; Gallo, Richard L.

    2016-01-01

    Patients with atopic dermatitis (AD) have an abnormal skin barrier and are frequently colonized by S. aureus. In this study we investigated if S. aureus penetrates the epidermal barrier of subjects with AD and sought to understand the mechanism and functional significance of this entry. S. aureus was observed to be more abundant in the dermis of lesional skin from AD patients. Bacterial entry past the epidermis was observed in cultured human skin equivalents and in mice, but found to be increased in the skin of cathelicidin knockout (Camp−/−) and ovalbumin-sensitized filaggrin mutant (FLGft/ft) mice. S. aureus penetration through the epidermis was dependent on bacterial viability and protease activity as killed bacteria or a protease-null mutant strain of S. aureus was unable to penetrate. Entry of S. aureus directly correlated with increased expression of IL4, IL13, IL22, TSLP and other cytokines associated with AD, and with decreased expression of cathelicidin. These data illustrate how abnormalities of the epidermal barrier in AD can alter the balance of S. aureus entry into the dermis and provides an explanation for how such dermal dysbiosis results in increased inflammatory cytokines and exacerbation of disease. PMID:27381887

  3. Molecular characterization of Staphylococcus aureus from outpatients in the Caribbean reveals the presence of pandemic clones

    PubMed Central

    Dumortier, C.; Hafer, C.; Taylor, B. S.; Sánchez E, J.; Rodriguez-Taveras, C.; Leon, P.; Rojas, R.; Olive, C.; Lowy, F. D.

    2011-01-01

    Staphylococcus aureus infections continue to pose a global public health problem. Frequently, this epidemic is driven by the successful spread of single S. aureus clones within a geographic region, but international travel has been recognized as a potential risk factor for S. aureus infections. To study the molecular epidemiology of S. aureus infections in the Caribbean, a major international tourist destination, we collected methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates from community-onset infections in the Dominican Republic (n=112) and Martinique (n=143). Isolates were characterized by a combination of pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing (MLST) typing. In Martinique, MRSA infections (n=56) were mainly caused by t304-ST8 strains (n=44), whereas MSSA isolates were derived from genetically diverse backgrounds. Among MRSA strains (n=22) from the Dominican Republic, ST5, ST30, and ST72 predominated, while ST30 t665-PVL+ (30/90) accounted for a substantial number of MSSA infections. Despite epidemiological differences in sample collections from both countries, a considerable number of MSSA infections (~10%) were caused by ST5 and ST398 isolates at each site. Further phylogenetic analysis suggests the presence of lineages shared by the two countries, followed by recent genetic diversification unique to each site. Our findings also imply the frequent import and exchange of international S. aureus strains in the Caribbean. PMID:21789605

  4. 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.

  5. Staphylococcus aureus intramammary infection affects milk yield and SCC of dairy cows.

    PubMed

    Botaro, Bruno Garcia; Cortinhas, Cristina Simões; Dibbern, Aline Gerato; e Silva, Luis Felipe Prada; Benites, Nilson Roberti; dos Santos, Marcos Veiga

    2015-01-01

    Staphylococcus aureus (S. aureus) is the most prevalent infectious microorganism affecting dairy cattle worldwide, and its pathogenic characteristics facilitate its spread in dairy herds. S. aureus intramammary infections (IMI) are mainly subclinical, and associated losses can exceed average herd losses where the pathogen is not isolated. However, the extent it affects milk composition at udder and quarter levels is still unknown, and cow composite milk losses may be underestimated due to the dilution effect. The aim of this study was to investigate the effects of S. aureus subclinical mastitis on mammary quarter milk yield and composition. In order to determine the effects of the pathogen on milk yield and composition at quarter level, a pairwise comparison of infected and non-infected mammary quarters (n = 28) from two dairy herds was carried out. Quarters were individually milked, and milk production and composition were assessed. S. aureus has increased somatic cell counts at quarter level; however, no effect of S. aureus IMI on milk lactose, fat, and protein contents was observed. Fat yield from infected quarters decreased, but losses due to the infection caused by S. aureus were not associated with quarter positioning in cows.

  6. Characterization of Staphylococcus aureus in Goose Feces from State Parks in Northeast Ohio.

    PubMed

    Thapaliya, Dipendra; Dalman, Mark; Kadariya, Jhalka; Little, Katie; Mansell, Victoria; Taha, Mohammed Y; Grenier, Dylan; Smith, Tara C

    2017-03-10

    Staphylococcus aureus can colonize a range of species. Although numerous studies have isolated pathogenic bacteria from wild birds, very little is known regarding S. aureus and their potential to spread methicillin-resistant (MRSA) strains. The objective of this study was to determine the presence and molecular characteristics of S. aureus in geese fecal samples collected from ten state parks across Northeast Ohio (NEO). A total of 182 fecal samples from Canada geese (Branta canadensis) were collected in April 2015. Isolates were characterized using multi-locus sequence (MLST) and spa typing, as well as PCR to detect the presence of Panton-Valentine leukocidin (PVL), mecA, and scn genes. Antibiotic susceptibility testing was done via Vitek-2 system. The overall contamination by S. aureus in fecal samples was 7.1% (13/182); 7/182 (3.8%) were MRSA and 6/182 (3.3%) were methicillin-susceptible S. aureus (MSSA). One isolate was positive for PVL. A total of eight different spa types were observed. MLST included ST5, ST8, ST291, ST298, and ST2111. One (7.7%) MSSA isolate was multi-drug resistant. The S. aureus contamination in NEO state parks ranged from 0% (park 1, 4, 8, 9) to 35% (7/20) (park 5). Parks 2, 3, 6, and 7 had 5% (1/20) positive. The results of this study indicate that the feces of geese collected at various state parks in NEO may harbor S. aureus.

  7. Staphylococcus aureus Nasal Carriers Among Medical Students in A Medical School.

    PubMed

    Syafinaz, A M; Nur Ain, N Z; Nadzirahi, S N; Fatimah, J S; Shahram, A; Nasir, M D M

    2012-12-01

    Staphylococcus aureus is usually considered a colonizer but can result in infections under favourable conditions, especially in the healthcare setting. Healthcare workers can be colonized by S. aureus, and may transmit them to patients under their care. We conducted a cross sectional study to determine the prevalence of S. aureus nasal carriers among medical students in Universiti Putra Malaysia (UPM) (from January to June 2011). Our study involved 209 medical students comprising of 111 and 97 preclinical and clinical students respectively. A selfadministered questionnaire was distributed and nasal swabs were collected. Upon identification, the antibiotic susceptibility of the isolates was examined followed by categorical analysis (Chi-square and Fisher's exact tests) with factors associated with S. aureus nasal carriage. Twenty one (10%) S. aureus strains were isolated from 209 nasal swab samples. 14 isolates were from pre-clinical students while the remaining seven were from clinical students. There was no significant association between gender, ethnicity, health status, skin infection and students' exposure to hospital environment with S. aureus nasal carriage (p>0.05). Nineteen (90.5%) isolates were resistant to penicillin and there was also no significant association between penicillin resistant and the students' groups. One (5.3%) isolate was resistant to erythromycin. There was no methicillin-resistant S. aureus isolated in this study.

  8. Distribution and Inhibition of Liposomes on Staphylococcus aureus and Pseudomonas aeruginosa Biofilm

    PubMed Central

    Dong, Dong; Thomas, Nicky; Thierry, Benjamin; Vreugde, Sarah; Prestidge, Clive A.; Wormald, Peter-John

    2015-01-01

    Background Staphylococcus aureus and Pseudomonas aeruginosa are major pathogens in chronic rhinosinusitis (CRS) and their biofilms have been associated with poorer postsurgical outcomes. This study investigated the distribution and anti-biofilm effect of cationic (+) and anionic (-) phospholipid liposomes with different sizes (unilamellar and multilamellar vesicle, ULV and MLV respectively) on S. aureus and P. aeruginosa biofilms. Method Specific biofilm models for S. aureus ATCC 25923 and P. aeruginosa ATCC 15692 were established. Liposomal distribution was determined by observing SYTO9 stained biofilm exposed to DiI labeled liposomes using confocal scanning laser microscopy, followed by quantitative image analysis. The anti-biofilm efficacy study was carried out by using the alamarBlue assay to test the relative viability of biofilm treated with various liposomes for 24 hours and five minutes. Results The smaller ULVs penetrated better than larger MLVs in both S. aureus and P. aeruginosa biofilm. Except that +ULV and –ULV displayed similar distribution in S. aureus biofilm, the cationic liposomes adhered better than their anionic counterparts. Biofilm growth was inhibited at 24-hour and five-minute exposure time, although the decrease of viability for P. aeruginosa biofilm after liposomal treatment did not reach statistical significance. Conclusion The distribution and anti-biofilm effects of cationic and anionic liposomes of different sizes differed in S. aureus and P. aeruginosa biofilms. Reducing the liposome size and formulating liposomes as positively charged enhanced the penetration and inhibition of S. aureus and P. aeruginosa biofilms. PMID:26125555

  9. Determination of enterotoxigenic and methicillin resistant Staphylococcus aureus in ice cream.

    PubMed

    Gücükoğlu, Ali; Çadirci, Özgür; Terzi, Göknur; Kevenk, T Onur; Alişarli, Mustafa

    2013-05-01

    The aim of this study was to determine the prevalence of enterotoxigenic and methicillin-resistant Staphylococcus aureus in ice creams. After culture-based identification of isolates, the presence of 16S rRNA and nuc was confirmed by mPCR. S. aureus was identified in 18 of 56 fruity (32.1%), 4 of 32 vanilla (12.5%), and 1 of 12 chocolate (8.3%) ice creams. S. aureus was identified as 38 isolates in 23 ice cream samples by culture-based techniques, but only 35 isolates were confirmed by PCR as S. aureus. To determine the enterotoxigenic properties of PCR-confirmed S. aureus isolates, a toxin detection kit was used (SET RPLA®). Of the 12 enterotoxigenic S. aureus isolates, 9 SEB (75%), 1 SED (8.3%), 1 SEB+SED (8.3%), and 1 SEA+SEB+SED (8.3%) expressing isolates were found. The presence of enterotoxin genes (sea, seb, sed) was identified in 13 (37.1%) out of 35 isolates by the mPCR technique. In the ice cream isolates, the sea, seb, and sed genes were detected: 1 sea (7.6%), 9 seb (69.2%), 1 sed (7.6%), 1 seb+sed (7.6%), and 1 sea+seb+sed (7.6%), respectively. The sec gene was not detected in any of these isolates. One of the 35 (2.8%) S. aureus strain was mecA positive.

  10. The Frequency of Staphylococcus aureus Isolated from Endocervix of Infertile Women in Northwest Iran

    PubMed Central

    Akhi, Mohammad Taghi; Esmailkhani, Aylin; Sadeghi, Javid; Niknafs, Behrooz; Farzadi, Laya; Akhi, Aydin; Nasab, Elmira Najafi

    2017-01-01

    Background Infertility is one of the major social issues. Due to the asymptomatic cervical infection associated with Staphylococcus aureus (S. aureus), the majority of patients remain undiagnosed. The present study intended to assess the frequency of S. aureus isolated from infertile women’s endocervix in northwest Iran. Materials and Methods In a descriptive cross sectional study, specimens were randomly collected during vagina examination using a sterile speculum and swabbing. After performance of antibiotic susceptibility testing, polymerase chain reaction (PCR) was used to identify methicillin-resistance S. aureus (MRSA) and toxic shock syndrome toxin-1 (TSST-1). Results About 26 (26%) and 9 (9%) women’s urogenital tracts were colonized by S. aureus and Candida spp., respectively, of which three (11.5%) patients were infected with fungi and S. aureus, simultaneously. Antibiotic susceptibility results showed high activity of vancomycin and co-trimoxazole on isolates. Regarding PCR results, mecA sequences were detected in 7 (26.9%) strains, whilst the tst gene encoding TSST-1 was not detected in any of clinical strains. Conclusion The prevalence of S. aureus was very high in infertile women. Therefore, it demands all patients undergoing infertility treatment to be investigated thoroughly for this type of infection. PMID:28367302

  11. Virulence and immunity of Staphylococcus aureus BB and certain deficient mutants.

    PubMed Central

    Hasegawa, N; San Clemente, C L

    1978-01-01

    Coagulase-negative and deoxyribonuclease-negative mutants were isolated from Staphylococcus aureus BB by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. Comparison of virulence (50% lethal dose) to mice of these six mutant strains and S. aureus BB was determined by both intravenous and intraperitoneal routes. The ratios of the 50% lethal dose of coagulase-negative mutants to that of the parental strain S. aureus BB ranged from 201 to 403 for intravenous infection and 30.7 to 52.7 for intraperitoneal infection. The virulence of deoxyribonuclease-negative mutants was essentially the same as that of S. aureus BB. When mice were immunized subcutaneously with live S. aureus BB or its deoxyribonuclease-negative mutants, the resulting protection against the intravenous challenge of S. aureus BB was remarkable. The ratios of the 50% lethal dose for the mice that were immunized by these strains to that for the untreated mice extended from 40.1 to 60.6 for intravenous infection and 6.61 to 11.5 for the intraperitoneal route. However, no effect against S. aureus BB challenge was shown in the mice that were immunized with coagulase-negative mutants. PMID:730368

  12. Analysis of the features of 45 identified CRISPR loci in 32 Staphylococcus aureus.

    PubMed

    Yang, Siyu; Liu, Jing; Shao, Fuye; Wang, Pengfei; Duan, Guangcai; Yang, Haiyan

    2015-08-28

    Staphylococcus aureus (S. aureus) is a common pathogen that can cause serious infections, even death. Because of the horizontal gene transfer (HGT) of antibiotic resistance genes, the drug resistant condition is becoming increasingly prevalent. Recently, an adaptive immunity system, named clustered regularly interspaced short palindromic repeats (CRISPR), was discovered and demonstrated to confer a defense against foreign invading elements that may carry the antibiotic resistance genes. In this study, we reveal the features of 45 identified CRISPR loci and the CRISPR associated gene (Cas) in 32 S. aureus strains from CRISPR database. Five spacers of S. aureus 08BA02176 and MSHR1132 were homologous with foreign genetic sequences from phages or plasmids, even containing a spacer sequence identical to part of some phages' genomes containing lukPV gene that encodes the PVL toxin. Many S. aureus strains with the same CRISPR type shared the same MLST type. CRISPR loci that had 3 or more similar protein loci mostly belonged to the same CRISPR type. We came to the conclusion that the CRISPR/Cas of strains 08BA02176 and MSHR1132 were inherited from a common ancestor or recombined from Staphylococcus lugdunensis. CRISPR loci can be mobilized and can transfer among different but closely related species, and the same types of MLST strains exhibit a higher affinity to the same types of CRISPR loci. Bacteriophages may be the predominant challenge facing S. aureus. The CRISPR/Cas structure may limit the transmission of bacterial virulence among S. aureus.

  13. Inhibitory effect of totarol on exotoxin proteins hemolysin and enterotoxins secreted by Staphylococcus aureus.

    PubMed

    Shi, Ce; Zhao, Xingchen; Li, Wenli; Meng, Rizeng; Liu, Zonghui; Liu, Mingyuan; Guo, Na; Yu, Lu

    2015-10-01

    Staphylococcus aureus (S. aureus) causes a wide variety of infections, which are of major concern worldwide. S. aureus produces multiple virulence factors, resulting in food infection and poisoning. These virulence factors include hyaluronidases, proteases, coagulases, lipases, deoxyribonucleases and enterotoxins. Among the extracellular proteins produced by S. aureus that contribute to pathogenicity, the exotoxins α-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) are thought to be of major significance. Totarol, a plant extract, has been revealed to inhibit the proliferation of several pathogens effectively. However, there are no reports on the effects of totarol on the production of α-hemolysin, SEA or SEB secreted by S. aureus. The aim of this study was to evaluate the effects of totarol on these three exotoxins. Hemolysis assay, western blotting and real-time reverse transcriptase-PCR assay were performed to identify the influence of graded subinhibitory concentrations of totarol on the production of α-hemolysin and the two major enterotoxins, SEA and SEB, by S. aureus in a dose-dependent manner. Moreover, an enzyme linked immunosorbent assay showed that the TNF-α production of RAW264.7 cells stimulated by S. aureus supernatants was inhibited by subinhibitory concentrations of totarol. Form the data, we propose that totarol could potentially be used as a promising natural compound in the food and pharmaceutical industries.

  14. Short communication: Antimicrobial susceptibility profiling and genotyping of Staphylococcus aureus isolates from bovine mastitis in Poland.

    PubMed

    Jagielski, T; Puacz, E; Lisowski, A; Siedlecki, P; Dudziak, W; Międzobrodzki, J; Krukowski, H

    2014-10-01

    Staphylococcus aureus is the predominant causative agent of bovine mastitis, a disease that remains a major economic burden for the dairy industry worldwide. In this study, the antimicrobial resistance patterns and the genetic composition of 80 S. aureus mastitis isolates collected from 14 dairy farms in Eastern Poland were determined. Of the 10 antimicrobial agents evaluated, only testing for penicillin G produced drug resistance. As 41% of the S. aureus isolates were penicillin resistant, this drug along with other β-lactamase-sensitive β-lactams, should rather not be considered for the treatment of bovine mastitis caused by S. aureus. Upon genotyping, with a triplex PCR method, a total of 11 distinct PCR types were produced. The population structure of S. aureus isolates was highly clonal, with 1 predominant genotype circulating on each farm. The observed similarities in the genotype composition of S. aureus populations from geographically distant farms underscore the significance of interfarm transmission of S. aureus in Poland. This, in turn, argues for the establishment of a nationwide surveillance program for bovine mastitis due to this pathogen.

  15. Biofilm formation by Staphylococcus aureus isolates from a dental clinic in Konya, Turkey.

    PubMed

    Torlak, Emrah; Korkut, Emre; Uncu, Ali T; Şener, Yağmur

    2017-02-14

    The ability of Staphylococcus aureus to form biofilm is considered to be a major virulence factor influencing its survival and persistence in both the environment and the host. Biofilm formation in S. aureus is most frequently associated with production of polysaccharide intercellular adhesion by ica operon-encoded enzymes. The present work aimed at evaluating the in vitro biofilm production and presence of the icaA and icaD genes in S. aureus isolates from a dental clinic in Konya, Turkey. The surfaces of inanimate objects were sampled over a period of six months. S. aureus isolates were subjected to Congo Red Agar (CRA) and crystal violet (CV) staining assays to evaluate their ability of biofilm production, while the presence of the icaA and icaD genes was determined by polymerase chain reaction. S. aureus contamination was detected in 13.2% of the environmental samples. All the 32 isolates were observed to be positive for both the icaA and icaD genes. Phenotypic evaluations revealed that CV staining assay is a more reliable alternative to CRA assay to determine biofilm formation ability. A high percentage of agreement (91%) was observed between the results from CV staining and ica genes' detection assays. Phenotypic and genotypic evaluations should be combined to detect biofilm formation in S. aureus. Our findings indicate that dental clinic environments should be considered as potential reservoir for biofilm-producing S. aureus and thus cross contamination.

  16. Staphylococcus aureus and surgical site infections: benefits of screening and decolonization before surgery.

    PubMed

    Humphreys, H; Becker, K; Dohmen, P M; Petrosillo, N; Spencer, M; van Rijen, M; Wechsler-Fördös, A; Pujol, M; Dubouix, A; Garau, J

    2016-11-01

    Surgical site infections (SSIs) are among the most common healthcare-associated infections, and contribute significantly to patient morbidity and healthcare costs. Staphylococcus aureus is the most common microbial cause. The epidemiology of S. aureus is changing with the dissemination of newer clones and the emergence of mupirocin resistance. The prevention and control of SSIs is multi-modal, and this article reviews the evidence on the value of screening for nasal carriage of S. aureus and subsequent decolonization of positive patients pre-operatively. Pre-operative screening, using culture- or molecular-based methods, and subsequent decolonization of patients who are positive for meticillin-susceptible S. aureus and meticillin-resistant S. aureus (MRSA) reduces SSIs and hospital stay. This applies especially to major clean surgery, such as cardiothoracic and orthopaedic, involving the insertion of implanted devices. However, it requires a multi-disciplinary approach coupled with patient education. Universal decolonization pre-operatively without screening for S. aureus may compromise the capacity to monitor for the emergence of new clones of S. aureus, contribute to mupirocin resistance, and prevent the adjustment of surgical prophylaxis for MRSA (i.e. replacement of a beta-lactam agent with a glycopeptide or alternative).

  17. Rapid detection of viral antibodies based on multifunctional Staphylococcus aureus nanobioprobes.

    PubMed

    Qiao, Jinjuan; Li, Yunpeng; Wei, Cuihua; Yang, Hang; Yu, Junping; Wei, Hongping

    2016-12-01

    Biosynthesis of nanoparticles inside S. aureus cells has enhanced the sensitivity of immunoassays based on the S. aureus nanoparticles. However, the current methods are limited to antigen detection by conjugating IgG antibodies on S. aureus nanoparticles. In this study, a simple way to conjugate antigens to the S. aureus nanobioparticles was developed by utilizing a cell wall binding domain (CBD) from a bacteriophage lysin PlyV12. Based on this novel design, simple agglutination tests of the IgG antibodies of Ebola virus (EBOV) nucleoprotein (NP) and Middle East Respiratory Virus (MERS) NP in rabbit sera were successfully developed by conjugating the S. aureus nanobioparticles with two fusion proteins EBOV NP- CBD and MERS NP-CBD, respectively. The conjugation was done easily by just mixing the fusion proteins with the S. aureus nanoparticles. The detection time was within 20 min without any special equipment or expertise. As far as we know, this is the first time to realize the detection of viral antibodies based on S. aureus nanoparticles.

  18. Sclareol protects Staphylococcus aureus-induced lung cell injury via inhibiting alpha-hemolysin expression.

    PubMed

    Ouyang, Ping; Sun, Mao; He, Xuewen; Wang, Kaiyu; Yin, Zhongqiong; Fu, Hualin; Li, Yinglun; Geng, Yi; Shu, Gang; He, Changliang; Liang, Xiaoxia; Lai, Weiming; Li, Lixia; Zou, Yuanfeng; Song, Xu; Yin, Lizi

    2016-09-23

    Staphylococcus aureus (S. aureus) is a common Gram-positive bacterium that causes serious infections in human and animals. With the continuous emergence of the methicillin-resistant S. aureus (MRSA) strains, antibiotics have limited efficacy in treating MRSA infections. Accordingly, novel agents that act on new targets are desperately needed to combat these infections. S. aureus alpha-hemolysin plays an indispensable role in its pathogenicity. In this study, we demonstrate that sclareol, a fragrant chemical compound found in clary sage, can prominently decrease alpha-hemolysin secretion in S. aureus strain USA300 at sub-inhibitory concentrations. Hemolysis assays, western-blotting and RT-PCR were used to detect the production of alpha-hemolysin in the culture supernatant. When USA300 was co-cultured with and A549 epithelial cells, sclareol could protect A549 cells at a final concentration of 8 µg/ml. The protective capability of sclareol against the USA300-mediated injury of A549 cells was further shown by cytotoxicity assays and live/dead analysis. In conclusion, sclareol was shown to inhibit the production of S. aureus alpha-hemolysin. Sclareol has potential for development as a new agent to treat S. aureus infections.

  19. Phage sensitivity and prophage carriage in Staphylococcus aureus isolated from foods in Spain and New Zealand.

    PubMed

    Gutiérrez, Diana; Rodríguez-Rubio, Lorena; García, Pilar; Billington, Craig; Premarante, Aruni; Rodríguez, Ana; Martínez, Beatriz

    2016-08-02

    Bacteriophages (phages) are a promising tool for the biocontrol of pathogenic bacteria, including those contaminating food products and causing infectious diseases. However, the success of phage preparations is limited by the host ranges of their constituent phages. The phage resistance/sensitivity profile of eighty seven Staphylococcus aureus strains isolated in Spain and New Zealand from dairy, meat and seafood sources was determined for six phages (Φ11, K, ΦH5, ΦA72, CAPSa1 and CAPSa3). Most of the S. aureus strains were sensitive to phage K (Myoviridae) and CAPSa1 (Siphoviridae) regardless of their origin. There was a higher sensitivity of New Zealand S. aureus strains to phages isolated from both Spain (ΦH5 and ΦA72) and New Zealand (CAPSa1 and CAPSa3). Spanish phages had a higher infectivity on S. aureus strains of Spanish dairy origin, while Spanish strains isolated from other environments were more sensitive to New Zealand phages. Lysogeny was more prevalent in Spanish S. aureus compared to New Zealand strains. A multiplex PCR reaction, which detected ΦH5 and ΦA72 sequences, indicated a high prevalence of these prophages in Spanish S. aureus strains, but were infrequently detected in New Zealand strains. Overall, the correlation between phage resistance and lysogeny in S. aureus strains was found to be weak.

  20. Antimicrobial resistance pattern of methicillin-resistant Staphylococcus aureus in the food industry.

    PubMed

    Paludi, D; Vergara, A; Festino, A R; Di Ciccio, P; Costanzo, C; Conter, M; Zanardi, E; Ghidini, S; Ianieri, A

    2011-01-01

    There is increasing concern about the impact on public health of methicillin-resistant Staphylococcus aureus (MRSA) associated with animal food products. MRSA remains a serious problem because of the high incidence and multidrug resistance of the strains, even for strains isolated from foods, food environments and food handlers. The objectives of this study are: (i) to evaluate the susceptibility of S. aureus strains isolated from food, food handlers and food-processing environments to 14 antibiotics currently used in veterinary and human therapy; (ii) to assess the presence of the mecA gene. A total of 1007 samples were collected from food, food handlers, and environments and were analyzed for the presence of S. aureus. S. aureus was present in 165 of the 1007 samples. A total of 157 isolates were methicillin-susceptible S. aureus (MSSA) and 8 isolates were MRSA. In particular, out of 8 MRSA strains detected, 4 strains harboured the mecA gene. All MRSA strains were resistant to at least one of the tested antibiotics and 6 strains demonstrated multi-resistance. Considering the high level of resistances in S. aureus and the isolation of MRSA strains, the surveillance of antimicrobial resistance and the spreading of this pathogen is of crucial importance in the food production chain. These data are useful in improving background data on antimicrobial resistance of S. aureus isolated from food, processing environments and food handlers, supporting the prudent use of antibiotics and the development of international control programs.

  1. Organic extracts from Indigofera suffruticosa leaves have antimicrobial and synergic actions with erythromycin against Staphylococcus aureus.

    PubMed

    Bezerra Dos Santos, Ana Thereza; Araújo, Tiago Ferreira da Silva; Nascimento da Silva, Luis Cláudio; da Silva, Cleideana Bezerra; de Oliveira, Antonio Fernando Morais; Araújo, Janete Magali; Correia, Maria Tereza Dos Santos; Lima, Vera Lúcia de Menezes

    2015-01-01

    A characteristic feature of Staphylococcus aureus is its ability to acquire resistance to antimicrobial agents. There is a need, therefore, for new approaches to combat this pathogen; for example, employing a combination of plant-derived products and antibiotics to overcome bacterial resistance. Indigofera suffruticosa is a plant popularly used to treat infections and has verified antimicrobial action. Here, we investigate the antimicrobial activity of different extracts from I. suffruticosa against S. aureus and their synergistic effects with erythromycin. Leaves of I. suffruticosa were extracted sequentially using diethyl ether, chloroform and acetone and the antimicrobial activity of each extract then tested against nine clinical isolates of S. aureus. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by microdilution tests, while the fractional inhibitory concentration (FIC) was assessed by checkerboard assay. All organic solvent extracts showed antimicrobial activity against S. aureus strains. The acetone extract was the most potent inhibitor of S. aureus (MIC and MBC of 0.78 and 3.12 mg/mL), followed by the chloroform extract (MIC and MBC of 3.12 and 6.25 mg/mL). Furthermore, acetone or chloroform extracts of I. suffruticosa enhanced the activity of erythromycin against S. aureus (FIC ≤ 0.5). We conclude that organic extracts from leaves of I. suffruticosa, alone or combined with erythromycin, are promising natural products for the development of new anti-S. aureus formulations.

  2. Organic extracts from Indigofera suffruticosa leaves have antimicrobial and synergic actions with erythromycin against Staphylococcus aureus

    PubMed Central

    Bezerra dos Santos, Ana Thereza; Araújo, Tiago Ferreira da Silva; Nascimento da Silva, Luis Cláudio; da Silva, Cleideana Bezerra; de Oliveira, Antonio Fernando Morais; Araújo, Janete Magali; Correia, Maria Tereza dos Santos; Lima, Vera Lúcia de Menezes

    2015-01-01

    A characteristic feature of Staphylococcus aureus is its ability to acquire resistance to antimicrobial agents. There is a need, therefore, for new approaches to combat this pathogen; for example, employing a combination of plant-derived products and antibiotics to overcome bacterial resistance. Indigofera suffruticosa is a plant popularly used to treat infections and has verified antimicrobial action. Here, we investigate the antimicrobial activity of different extracts from I. suffruticosa against S. aureus and their synergistic effects with erythromycin. Leaves of I. suffruticosa were extracted sequentially using diethyl ether, chloroform and acetone and the antimicrobial activity of each extract then tested against nine clinical isolates of S. aureus. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by microdilution tests, while the fractional inhibitory concentration (FIC) was assessed by checkerboard assay. All organic solvent extracts showed antimicrobial activity against S. aureus strains. The acetone extract was the most potent inhibitor of S. aureus (MIC and MBC of 0.78 and 3.12 mg/mL), followed by the chloroform extract (MIC and MBC of 3.12 and 6.25 mg/mL). Furthermore, acetone or chloroform extracts of I. suffruticosa enhanced the activity of erythromycin against S. aureus (FIC ≤ 0.5). We conclude that organic extracts from leaves of I. suffruticosa, alone or combined with erythromycin, are promising natural products for the development of new anti-S. aureus formulations. PMID:25699022

  3. High-resolution subtyping of Staphylococcus aureus strains by means of Fourier-transform infrared spectroscopy.

    PubMed

    Johler, Sophia; Stephan, Roger; Althaus, Denise; Ehling-Schulz, Monika; Grunert, Tom

    2016-05-01

    Staphylococcus aureus causes a variety of serious illnesses in humans and animals. Subtyping of S. aureus isolates plays a crucial role in epidemiological investigations. Metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy is commonly used to identify microbes at species as well as subspecies level. In this study, we aimed to assess the suitability of FTIR spectroscopy as a tool for S. aureus subtyping. To this end, we compared the subtyping performance of FTIR spectroscopy to other subtyping methods such as pulsed field gel electrophoresis (PFGE) and spa typing in a blinded experimental setup and investigated the ability of FTIR spectroscopy for identifying S. aureus clonal complexes (CC). A total of 70 S. aureus strains from human, animal, and food sources were selected, for which clonal complexes and a unique virulence and resistance gene pattern had been determined by DNA microarray analysis. FTIR spectral analysis resulted in high discriminatory power similar as obtained by spa typing and PFGE. High directional concordance was found between FTIR spectroscopy based subtypes and capsular polysaccharide expression detected by FTIR spectroscopy and the cap specific locus, reflecting strain specific expression of capsular polysaccharides and/or other surface glycopolymers, such as wall teichoic acid, peptidoglycane, and lipoteichoic acid. Supervised chemometrics showed only limited possibilities for differentiation of S. aureus CC by FTIR spectroscopy with the exception of CC45 and CC705. In conclusion, FTIR spectroscopy represents a valuable tool for S. aureus subtyping, which complements current molecular and proteomic strain typing.

  4. Genetic Diversity and Antibiotic Resistance Patterns of Staphylococcus Aureus Isolated from Leaf Vegetables in Korea.

    PubMed

    Hong, Jisoo; Kim, Yangkyun; Kim, Jonguk; Heu, Sunggi; Kim, Se-ri; Kim, Kwang-Pyo; Roh, Eunjung

    2015-07-01

    Staphylococcus aureus is an important foodborne pathogen on global basis. The current study investigated the genetic patterns in S. aureus isolates from leaf vegetables (n = 53). Additional isolates from livestock (n = 31) and humans (n = 27) were compared with the leaf vegetable isolates. Genes associated with toxins, antibiotic resistance, and pulsed-field gel electrophoresis (PFGE) patterns were analyzed. At least 1 enterotoxin-encoding gene (sea, seb, sec, sed, and see) was detected in 11 of 53 (20.75%) leaf vegetable isolates. When the agr (accessory gene regulator) grouping was analyzed, agr II was the major group, whereas agr IV was not present in leaf vegetable isolates. All S. aureus isolates from leaf vegetables were resistant to more than one of the antibiotics tested. Nineteen of 53 (35.85%) isolates from leaf vegetables exhibited multidrug-resistance, and 11 of these were MRSA (methicillin-resistant S. aureus). A dendrogram displaying the composite types of S. aureus isolates from 3 origins was generated based on the combination of the toxin genes, agr genes, antibiotic resistance, and PFGE patterns. The isolates could be clustered into 8 major composite types. The genetic patterns of S. aureus isolates from leaf vegetables and humans were similar, whereas those from livestock had unique patterns. This suggests some S. aureus isolates from leaf vegetables to be of human origin.

  5. [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.

  6. 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

  7. 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

  8. [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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. SbnG, a Citrate Synthase in Staphylococcus aureus

    PubMed Central

    Kobylarz, Marek J.; Grigg, Jason C.; Sheldon, Jessica R.; Heinrichs, David E.; Murphy, Michael E. P.

    2014-01-01

    In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production. PMID:25336653

  17. 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

  18. [Effectiveness of alcoholic hand disinfectants against methicillin resistant Staphylococcus aureus].

    PubMed

    Kampf, G; Jarosch, R; Rüden, H

    1997-03-01

    In order to determine the efficacy of hand disinfectants based on alcohol against three MRSA strains and 3 methicillin-susceptible S. aureus strains (MSSA), 1-propanol (60%) as well as Sterillium and Spitaderm were investigated in the quantitative suspension test at various dilutions and reactions times (15, 30 and 60s). All undiluted disinfectants revealed reduction factors > 6 against MRSA and MSSA after 30s. Diluted disinfectants (50%) were significantly less effective against MRSA at short reaction times (15 s) (p < 0.05). Sterillium in a dilution of 50% did not reach 5 reduction factors against either MRSA or MSSA after 30 s. The impact of an appropriate use of hand disinfectants in order to break chains of infections with MRSA is obvious.

  19. 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.

  20. 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.

  1. 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.

  2. Quantitative microbial risk assessment for Staphylococcus aureus in natural and processed cheese in Korea.

    PubMed

    Lee, Heeyoung; Kim, Kyunga; Choi, Kyoung-Hee; Yoon, Yohan

    2015-09-01

    This study quantitatively assessed the microbial risk of Staphylococcus aureus in cheese in Korea. The quantitative microbial risk assessment was carried out for natural and processed cheese from factory to consumption. Hazards for S. aureus in cheese were identified through the literature. For exposure assessment, the levels of S. aureus contamination in cheeses were evaluated, and the growth of S. aureus was predicted by predictive models at the surveyed temperatures, and at the time of cheese processing and distribution. For hazard characterization, a dose-response model for S. aureus was found, and the model was used to estimate the risk of illness. With these data, simulation models were prepared with @RISK (Palisade Corp., Ithaca, NY) to estimate the risk of illness per person per day in risk characterization. Staphylococcus aureus cell counts on cheese samples from factories and markets were below detection limits (0.30-0.45 log cfu/g), and pert distribution showed that the mean temperature at markets was 6.63°C. Exponential model [P=1 - exp(7.64×10(-8) × N), where N=dose] for dose-response was deemed appropriate for hazard characterization. Mean temperature of home storage was 4.02°C (log-logistic distribution). The results of risk characterization for S. aureus in natural and processed cheese showed that the mean values for the probability of illness per person per day were higher in processed cheese (mean: 2.24×10(-9); maximum: 7.97×10(-6)) than in natural cheese (mean: 7.84×10(-10); maximum: 2.32×10(-6)). These results indicate that the risk of S. aureus-related foodborne illness due to cheese consumption can be considered low under the present conditions in Korea. In addition, the developed stochastic risk assessment model in this study can be useful in establishing microbial criteria for S. aureus in cheese.

  3. A very early-branching Staphylococcus aureus lineage lacking the carotenoid pigment staphyloxanthin.

    PubMed

    Holt, Deborah C; Holden, Matthew T G; Tong, Steven Y C; Castillo-Ramirez, Santiago; Clarke, Louise; Quail, Michael A; Currie, Bart J; Parkhill, Julian; Bentley, Stephen D; Feil, Edward J; Giffard, Philip M

    2011-01-01

    Here we discuss the evolution of the northern Australian Staphylococcus aureus isolate MSHR1132 genome. MSHR1132 belongs to the divergent clonal complex 75 lineage. The average nucleotide divergence between orthologous genes in MSHR1132 and typical S. aureus is approximately sevenfold greater than the maximum divergence observed in this species to date. MSHR1132 has a small accessory genome, which includes the well-characterized genomic islands, νSAα and νSaβ, suggesting that these elements were acquired well before the expansion of the typical S. aureus population. Other mobile elements show mosaic structure (the prophage ϕSa3) or evidence of recent acquisition from a typical S. aureus lineage (SCCmec, ICE6013 and plasmid pMSHR1132). There are two differences in gene repertoire compared with typical S. aureus that may be significant clues as to the genetic basis underlying the successful emergence of S. aureus as a pathogen. First, MSHR1132 lacks the genes for production of staphyloxanthin, the carotenoid pigment that confers upon S. aureus its characteristic golden color and protects against oxidative stress. The lack of pigment was demonstrated in 126 of 126 CC75 isolates. Second, a mobile clustered regularly interspaced short palindromic repeat (CRISPR) element is inserted into orfX of MSHR1132. Although common in other staphylococcal species, these elements are very rare within S. aureus and may impact accessory genome acquisition. The CRISPR spacer sequences reveal a history of attempted invasion by known S. aureus mobile elements. There is a case for the creation of a new taxon to accommodate this and related isolates.

  4. Cell-Surface Phenol Soluble Modulins Regulate Staphylococcus aureus Colony Spreading

    PubMed Central

    Kizaki, Hayato; Omae, Yosuke; Tabuchi, Fumiaki; Saito, Yuki; Sekimizu, Kazuhisa

    2016-01-01

    Staphylococcus aureus produces phenol-soluble modulins (PSMs), which are amphipathic small peptides with lytic activity against mammalian cells. We previously reported that PSMα1–4 stimulate S. aureus colony spreading, the phenomenon of S. aureus colony expansion on the surface of soft agar plates, whereas δ-toxin (Hld, PSMγ) inhibits colony-spreading activity. In this study, we revealed the underlying mechanism of the opposing effects of PSMα1–4 and δ-toxin in S. aureus colony spreading. PSMα1–4 and δ-toxin are abundant on the S. aureus cell surface, and account for 18% and 8.5% of the total amount of PSMα1–4 and δ-toxin, respectively, in S. aureus overnight cultures. Knockout of PSMα1–4 did not affect the amount of cell surface δ-toxin. In contrast, knockout of δ-toxin increased the amount of cell surface PSMα1–4, and decreased the amount of culture supernatant PSMα1–4. The δ-toxin inhibited PSMα3 and PSMα2 binding to the S. aureus cell surface in vitro. A double knockout strain of PSMα1–4 and δ-toxin exhibited decreased colony spreading compared with the parent strain. Expression of cell surface PSMα1–4, but not culture supernatant PSMα1–4, restored the colony-spreading activity of the PSMα1-4/δ-toxin double knockout strain. Expression of δ-toxin on the cell surface or in the culture supernatant did not restore the colony-spreading activity of the PSMα1-4/δ-toxin double knockout strain. These findings suggest that cell surface PSMα1–4 promote S. aureus colony spreading, whereas δ-toxin suppresses colony-spreading activity by inhibiting PSMα1–4 binding to the S. aureus cell surface. PMID:27723838

  5. Tracing and inhibiting growth of Staphylococcus aureus in barbecue cheese production after product recall.

    PubMed

    Johler, S; Zurfluh, K; Stephan, R

    2016-05-01

    Staphylococcal food poisoning is one of the most prevalent causes of foodborne intoxication worldwide. It is caused by ingestion of enterotoxins formed by Staphylococcus aureus during growth in the food matrix. Following a recall of barbecue cheese due to the detection of staphylococcal enterotoxins in Switzerland in July 2015, we analyzed the production process of the respective dairy. Although most cheese-making processes involve acidification to inhibit the growth of pathogenic bacteria, barbecue cheese has to maintain a pH >6.0 to prevent undesired melting of the cheese. In addition, the dairy decided to retain the traditional manual production process of the barbecue cheese. In this study, therefore, we aimed to (1) trace Staph. aureus along the barbecue cheese production process, and (2) develop a sustainable strategy to inhibit growth of Staph. aureus and decrease the risk of staphylococcal food poisoning without changing the traditional production process. To this end, we traced Staph. aureus in a step-wise blinded process analysis on 4 different production days using spa (Staphylococcus protein A gene) typing, DNA microarray profiling, and pulsed-field gel electrophoresis analysis. We subsequently selected a new starter culture and used a model cheese production including a challenge test assay to assess its antagonistic effect on Staph. aureus growth, as well as its sensory and technological implications. We detected Staph. aureus in 30% (37/124) of the collected samples taken from the barbecue cheese production at the dairy. This included detection of Staph. aureus in the final product on all 4 production days, either after enrichment or using quantitative detection. We traced 2 enterotoxigenic Staph. aureus strains (t073/CC45 and t282/CC45) colonizing the nasal cavity and the forearms of the cheesemakers to the final product. In the challenge test assay, we were able to show that the new starter culture inhibited growth of Staph. aureus while meeting

  6. Identification of potential sources of Staphylococcus aureus in herds with mastitis problems.

    PubMed

    Capurro, A; Aspán, A; Ericsson Unnerstad, H; Persson Waller, K; Artursson, K

    2010-01-01

    Staphylococcus aureus is a common udder pathogen of dairy cows that often causes herd problems. Various mastitis control programs have been used to combat the problem but have not always been efficient in preventing new Staph. aureus infections, indicating the presence of possible sources of infection other than those traditionally considered. Therefore, the aim of the study was to identify potential sources of infection relevant for Staph. aureus mastitis within 5 dairy herds with udder health problems caused by Staph. aureus. Samples were collected from milk of lactating cows, from body sites, and from the environment of lactating cows, dry cows, late pregnant heifers, young heifers 4 to 12 mo old, and heifer calves 0 to 3 mo old. Isolates of Staph. aureus were identified and compared using pulsed-field gel electrophoresis. Four to 7 unique Staph. aureus pulsotypes were found within each herd, with one strain predominating in milk in each herd. The milk pulsotypes were also frequently isolated in body samples, especially on hock skin, and in the immediate environment of lactating cows, and were sometimes found in other animal groups, especially in dry cows and heifer calves 0 to 3 mo old. The prevalence of Staph. aureus in milk and other types of samples varied markedly between herds. Staphylococcus aureus isolates with genotypes indistinguishable from those found in milk also dominated in extra-mammary sites within the dairy herds studied, and hock skin was identified as an important reservoir of Staph. aureus. The results contribute new knowledge necessary to improve strategies for udder health control in herds.

  7. Isothermal target and probe amplification assay for the real-time rapid detection of Staphylococcus aureus.

    PubMed

    Shin, Hyewon; Kim, Minhwan; Yoon, Eunju; Kang, Gyoungwon; Kim, Seungyu; Song, Aelee; Kim, Jeongsoon

    2015-04-01

    Staphylococcus aureus, the species most commonly associated with staphylococcal food poisoning, is one of the most prevalent causes of foodborne disease in Korea and other parts of the world, with much damage inflicted to the health of individuals and economic losses estimated at $120 million. To reduce food poisoning outbreaks by implementing prevention methods, rapid detection of S. aureus in foods is essential. Various types of detection methods for S. aureus are available. Although each method has advantages and disadvantages, high levels of sensitivity and specificity are key aspects of a robust detection method. Here, we describe a novel real-time isothermal target and probe amplification (iTPA) method that allows the rapid and simultaneous amplification of target DNA (the S. aureus nuc gene) and a fluorescence resonance energy transfer-based signal probe under isothermal conditions at 61 °C or detection of S. aureus in real time. The assay was able to specifically detect all 91 S. aureus strains tested without nonspecific detection of 51 non-S. aureus strains. The real-time iTPA assay detected S. aureus at an initial level of 10(1) CFU in overnight cultures of preenriched food samples (kiwi dressing, soybean milk, and custard cream). The advantage of this detection system is that it does not require a thermal cycler, reducing the cost of the real-time PCR and its footprint. Combined with a miniaturized fluorescence detector, this system can be developed into a simplified quantitative hand-held real-time device, which is often required. The iTPA assay was highly reliable and therefore may be used as a rapid and sensitive means of identifying S. aureus in foods.

  8. Selected Factors of Innate Immunity in Healthy Individuals with S. aureus Nasal Carriage.

    PubMed

    Karpiński, Tomasz M; Żaba, Zbigniew; Chudzicka-Strugała, Izabela; Szkaradkiewicz, Anna K; Jaworska, Agata; Zeidler, Agnieszka; Andrzejewska, Ewa; Szkaradkiewicz, Andrzej

    2016-01-01

    Nasal carriage of Staphylococcus aureus represents a well-defined factor of risk involving community and hospital-acquired infections. Recently a significance of several host factors has been pointed out and, in particular, of immune determinants in nasal S. aureus colonization. Therefore, this study aimed at analysis of manifestation involving manifestation in the nasal secretions of important components of the host innate immunity - human beta-defensin-2 (HBD-2), lysozyme (Ly), and interferon-gamma (IFN-γ) in healthy individuals and in persons with persistent carriage of S. aureus. The studies were conducted in two groups of healthy volunteers, encompassing non-carriers (group 1) or persistent carriers of S. aureus (group 2). Elisa assays were employed to evaluate levels of HBD-2, Ly, and IFN-γ in nasal secretions of the examined donors. In S. aureus carriers a significant variability of HBD-2 levels was detected, corresponding to, respectively, the high (averaging at 1.46 ng/ml) and the low (averaging at 0.13 ng/ml) secretory response of the defensin. The level of Ly in S. aureus carriers averaged at 1.46 μg/ml and it manifested no significant difference as compared to that noted in non-carriers. In turn, concentrations of IFN-γ in nasal secretions in the group of carriers of S. aureus amounted on the average to 81.7 pg/ml and they were 1.3-fold higher that in the group of non-carriers. The obtained results allow to conclude that IFN-γ secretion by the nasal cavity-colonizing S. aureus remains quantitatively insufficient to eliminate the pathogen. Nevertheless, a significant increase in levels of this host factor may be important for restriction of the staphylococcal colonization and protection against development of an invasive infection. In turn, the role of HBD-2 and Ly in inactivation of the colonizing S. aureus remains doubtful.

  9. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    PubMed Central

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  10. Antibacterial synergy between rosmarinic acid and antibiotics against methicillin-resistant Staphylococcus aureus

    PubMed Central

    Ekambaram, Sanmuga Priya; Perumal, Senthamil Selvan; Balakrishnan, Ajay; Marappan, Nathiya; Gajendran, Sabari Srinivasan; Viswanathan, Vinodhini

    2016-01-01

    Aim/Background: Medicinal plants have ability to resist microorganisms by synthesizing secondary metabolites such as phenols. Rosmarinic acid (RA) is a phenylpropanoid widely distributed in plants and well known as therapeutic and cosmetic agent. Methicillin-resistant Staphylococcus aureus (MRSA) which is resistant to all kinds of β-lactams, threatens even most potent antibiotics. To improve the efficiency of antibiotics against multi-drug resistant bacteria and to reduce the antibiotic dose, the antibacterial activity and the synergistic effect of RA with standard antibiotics against S. aureus and MRSA was investigated. Materials and Methods: Antibacterial activity of RA against S. aureus and a clinical isolate of MRSA was evaluated by agar well diffusion method. Minimum inhibitory concentration (MIC) of RA was determined by broth dilution method. Synergism of RA with various antibiotics against S. aureus and MRSA was studied by broth checkerboard method and time-kill kinetic assay. Effect of RA on microbial surface components recognizing adhesive matrix molecules (MSCRAMM’s) of S. aureus and MRSA was studied using sodium dodecyl sulfate - polyacrylamide gel electrophoresis. Results: MIC of RA was found to be 0.8 and 10 mg/ml against S. aureus and MRSA, respectively. RA was synergistic with vancomycin, ofloxacin, and amoxicillin against S. aureus and only with vancomycin against MRSA. The time-kill analysis revealed that synergistic combinations were a more effective than individual antibiotics. MSCRAMM’s protein expression of S. aureus and MRSA was markedly suppressed by RA + vancomycin combination rather than RA alone. Conclusion: The synergistic effects of RA with antibiotics were observed against S. aureus and MRSA. RA showed inhibitory effect on the surface proteins MSCRAMM’s. Even though RA was shown to exhibit a synergistic effect with antibiotics, the MIC was found to be higher. Thus, further studies on increasing the efficacy of RA can develop it

  11. Acacetin Protects Mice from Staphylococcus aureus Bloodstream Infection by Inhibiting the Activity of Sortase A.

    PubMed

    Bi, Chongwei; Dong, Xiaoyun; Zhong, Xiaobo; Cai, Hongjun; Wang, Dacheng; Wang, Lin

    2016-09-26

    Staphylococcus aureus (S. aureus) is a major cause of infection in hospitals and communities. Widespread dissemination of multi-drug resistant S. aureus is a serious threat to the health of humans and animals. An anti-virulence strategy has been widely considered as an alternative therapeutic approach. Inhibitors of virulence factors are able to treat S. aureus infections without influencing the growth or viability of bacteria and rarely lead to bacterial resistance. Sortase A (SrtA) is a membrane-associated cysteine transpeptidase that catalyzes up to 25 surface proteins that covalently bind to cell wall peptidoglycans. In S. aureus, most of these surface proteins have been identified as important virulence factors that are vital in bacterial pathogenesis. In the present study, we show that acacetin, a natural flavonoid compound, inhibits the activity of SrtA in S. aureus (IC50 = 36.46 ± 4.69 μg/mL, 128 μM) which affects the assembly of protein A (SpA) to cell walls and reduces the binding of S. aureus to fibrinogen (Fg). The mechanism of the interaction between acacetin and SrtA were preliminarily discussed using molecular dynamics simulations. The results suggested that acacetin adopted a compact conformation binding at the pocket of the SrtA via residues Arg-139 and Lys-140. By performing an animal infection model, we demonstrated that acacetin was able to protect mice from renal abscess formation induced by S. aureus and significantly increased survival rates. Taken together, these findings suggest that acacetin may be a promising candidate for the development of anti-S. aureus drugs.

  12. Characterization of the Humoral Immune Response during Staphylococcus aureus Bacteremia and Global Gene Expression by Staphylococcus aureus in Human Blood

    PubMed Central

    den Reijer, Paul Martijn; Lemmens-den Toom, Nicole; Kant, Samantha; Snijders, Susan V.; Boelens, Hélène; Tavakol, Mehri; Verkaik, Nelianne J.; van Belkum, Alex; Verbrugh, Henri A.; van Wamel, Willem J. B.

    2013-01-01

    Attempts to develop an efficient anti-staphylococcal vaccine in humans have so far been unsuccessful. Therefore, more knowledge of the antigens that are expressed by Staphylococcus aureus in human blood and induce an immune response in patients is required. In this study we further characterize the serial levels of IgG and IgA antibodies against 56 staphylococcal antigens in multiple serum samples of 21 patients with a S. aureus bacteremia, compare peak IgG levels between patients and 30 non-infected controls, and analyze the expression of 3626 genes by two genetically distinct isolates in human blood. The serum antibody levels were measured using a bead-based flow cytometry technique (xMAP®, Luminex corporation). Gene expression levels were analyzed using a microarray (BµG@s microarray). The initial levels and time taken to reach peak IgG and IgA antibody levels were heterogeneous in bacteremia patients. The antigen SA0688 was associated with the highest median initial-to-peak antibody fold-increase for IgG (5.05-fold) and the second highest increase for IgA (2.07-fold). Peak IgG levels against 27 antigens, including the antigen SA0688, were significantly elevated in bacteremia patients versus controls (P≤0.05). Expression of diverse genes, including SA0688, was ubiquitously high in both isolates at all time points during incubation in blood. However, only a limited number of genes were specifically up- or downregulated in both isolates when cultured in blood, compared to the start of incubation in blood or during incubation in BHI broth. In conclusion, most staphylococcal antigens tested in this study, including many known virulence factors, do not induce uniform increases in the antibody levels in bacteremia patients. In addition, the expression of these antigens by S. aureus is not significantly altered by incubation in human blood over time. One immunogenic and ubiquitously expressed antigen is the putative iron-regulated ABC transporter SA0688. PMID

  13. Red wines and flavonoids diminish Staphylococcus aureus virulence with anti-biofilm and anti-hemolytic activities.

    PubMed

    Cho, Hyun Seob; Lee, Jin-Hyung; Cho, Moo Hwan; Lee, Jintae

    2015-01-01

    The emergence of antibiotic resistant Staphylococcus aureus presents a worldwide problem that requires non-antibiotic strategies. This study investigated the anti-biofilm and anti-hemolytic activities of four red wines and two white wines against three S. aureus strains. All red wines at 0.5-2% significantly inhibited S. aureus biofilm formation and hemolysis by S. aureus, whereas the two white wines had no effect. Furthermore, at these concentrations, red wines did not affect bacterial growth. Analyses of hemolysis and active component identification in red wines revealed that the anti-biofilm compounds and anti-hemolytic compounds largely responsible were tannic acid, trans-resveratrol, and several flavonoids. In addition, red wines attenuated S. aureus virulence in vivo in the nematode Caenorhabditis elegans, which is killed by S. aureus. These findings show that red wines and their compounds warrant further attention in antivirulence strategies against persistent S. aureus infection.

  14. The Collagen-Binding Adhesin Is a Virulence Factor in Staphylococcus aureus Keratitis

    PubMed Central

    Rhem, Marcus N.; Lech, Elizabeth M.; Patti, Joseph M.; McDevitt, Damien; Höök, Magnus; Jones, Dan B.; Wilhelmus, Kirk R.

    2000-01-01

    A collagen-binding strain of Staphylococcus aureus produced suppurative inflammation in a rabbit model of soft contact lens-associated bacterial keratitis more often than its collagen-binding-negative isogenic mutant. Reintroduction of the cna gene on a multicopy plasmid into the mutant helped it regain its corneal adherence and infectivity. The topical application of a collagen-binding peptide before bacterial challenge decreased S. aureus adherence to deepithelialized corneas. These data suggest that the collagen-binding adhesin is involved in the pathogenesis of S. aureus infection of the cornea. PMID:10816547

  15. Predictive Model for Growth of Staphylococcus aureus on Raw Pork, Ham, and Sausage.

    PubMed

    Mansur, Ahmad Rois; Park, Joong-Hyun; Oh, Deog-Hwan

    2016-01-01

    Recent Staphylococcus aureus outbreaks linked to meat and poultry products underscore the importance of understanding the growth kinetics of S. aureus in these products at different temperatures. Raw pork, ham, and sausage (each 10 ± 0.3 g) were inoculated with a three-strain cocktail of S. aureus, resulting in an initial level of ca. 3 log CFU/g. Samples were stored isothermally at 10, 15, 20, 25, 30, 35, and 40°C, and S. aureus was enumerated at appropriate time intervals. The square root model was developed using experimental data collected from S. aureus grown on all samples (where data from raw pork, ham, and sausage were combined) so as to describe the growth rate of S. aureus as a function of temperature. The model was then compared with models for S. aureus growth on each individual sample in the experiments (raw pork, ham, or sausage) and the S. aureus ComBase models, as well as models for the growth of different types of pathogens (S. aureus, Escherichia coli O157:H7, Clostridium perfringens, Salmonella serovars, and Salmonella Typhimurium) on various types of meat and poultry products. The results show that the S. aureus model developed here based on the pooled data from all three pork products seems suitable for the prediction of S. aureus growth on different pork products under isothermal conditions from 10 to 25°C, as well as for S. aureus growth on different meat and poultry products at higher temperatures between 20 and 35°C. Regardless of some high deviations observed at temperatures between 25 and 40°C, the developed model still seems suitable to predict the growth of other pathogens on different types of meat and poultry products over the temperature ranges used here, especially for E. coli O157:H7 and Salmonella Typhimurium. The developed model, therefore, may be useful for estimating the effects of storage temperature on the behavior of pathogens in different meat and poultry products and for microbial risk assessments evaluating meat

  16. [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.

  17. [Aspects of the innate immune response to intramammary Staphylococcus aureus infections in cattle].

    PubMed

    Pereyra, Elizabet A L; Dallard, Bibiana E; Calvinho, Luis F

    2014-01-01

    Staphylococcus aureus is the pathogen most frequently isolated from bovine mastitis worldwide, causing chronic intramammary infections that limit profitable dairying. The objective of this article is to characterize the mechanisms involved in S. aureus mammary gland infections considering two different aspects of the infectious process; on the one hand, the aspects involved in the host innate immune response and on the other hand, the capacity of this organism to evade the immune system and interact with different cell types. The exploration of S. aureus interactions with the immune response of bovine mammary gland will help identify targets to outline new preventive or curative alternatives for intramammary infections caused by this organism.

  18. Staphylococcus aureus and Streptococcus pneumoniae interaction and response to pneumococcal vaccination: Myth or reality?

    PubMed Central

    Reiss-Mandel, Aylana; Regev-Yochay, Gili

    2016-01-01

    S. aureus and S. pneumoniae are both common pathogens that are also carried by a large proportion of healthy individuals in the nasal and nasopharyngeal spaces. A negative association between carriage of S. aureus and S. pneumoniae has been reported in children in various epidemiologic studies from different geographical regions. Most studies found that the negative association between S. pneumoniae and S. aureus was significant only for carriage of vaccine-type S. pneumoniae strains. In this review, we summarize the various suggested mechanisms of this suggested bacterial interference, and the clinical implications reported following PCV introduction to date in various geographical regions. PMID:26905680

  19. Disseminated Panton-Valentine Leukocidin-Positive Staphylococcus aureus infection in a child.

    PubMed

    Karli, Arzu; Yanik, Keramettin; Paksu, Muhammet S; Sensoy, Gulnar; Aykanat, Alper; Yener, Nazik; Belet, Nursen; Ceyhan, Meltem

    2016-04-01

    Panton-Valentine leukocidin (PVL) is an exotoxin that is produced by many strains of Staphylococcus aureus, and an important virulence factor. A PVL-positive S. aureus infection leads to rapid and severe infections of soft tissue and necrotizing pneumonia in healthy adolescents, and has a high mortality. This case report included a 12-year-old male patient who admitted for fever, respiratory distress and hip pain and was identified with necrotizing pneumonia with septic pulmonary embolism, psoas abscess, cellulitis and osteomyelitis. The PVL positive methicillin-sensitive S. aureus (MSSA) was isolated in the patient blood culture.

  20. Effect of rifampin on Staphylococcus aureus colonization in children on chronic peritoneal dialysis.

    PubMed

    Hanevold, C D; Fisher, M C; Waltz, R; Bartosh, S; Baluarte, H J

    1995-10-01

    The efficacy of rifampin in eliminating Staphylococcus aureus colonization was evaluated in a pediatric peritoneal dialysis population. Six children with documented nasal colonization were treated for 7 days with rifampin and cloxacillin. Although antimicrobial therapy eliminated nasal carriage in all patients, recolonization occurred in 66%. Exit site colonization proved difficult to eradicate with negative cultures documented in only 3 of 5 children after rifampin/cloxacillin therapy. Although S. aureus carriage is a risk factor for S. aureus infections, efforts to eradicate carriage with rifampin are hindered by rapid recolonization.

  1. Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes.

    PubMed

    Puah, Suat Moi; Chua, Kek Heng; Tan, Jin Ai Mary Anne

    2016-02-05

    Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52) of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5%) and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines.

  2. 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.

  3. Sub-inhibitory and post-antibiotic effects of spiramycin and erythromycin on Staphylococcus aureus.

    PubMed

    Webster, C; Ghazanfar, K; Slack, R

    1988-07-01

    The antibacterial responses of clinical isolates of Staphylococcus aureus to spiramycin and erythromycin were compared. Conventional MICs showed erythromycin-sensitive strains to be 16-32 times less sensitive to spiramycin. MBCs were only four to eight times higher for spiramycin. Erythromycin resistant S. aureus were more frequently encountered. Concentrations of both macrolides at 1/4 MIC produced antibacterial effects. Post-antibiotic effects were more marked with spiramycin. After 3 h exposure to 4 x MIC of antibiotic the delay in regrowth of S. aureus was 5 h for erythromycin and 9 h for spiramycin. In a continuous cultivation model, spiramycin produced an inhibitory effect on S. aureus for 12 h whereas the effect of erythromycin was only apparent for 6 h. In conclusion, spiramycin is more active against staphylococci in vitro than would be expected by its modest MICs.

  4. Staphylokinase promotes the establishment of Staphylococcus aureus skin infections while decreasing disease severity.

    PubMed

    Kwiecinski, Jakub; Jacobsson, Gunnar; Karlsson, Maria; Zhu, Xuefeng; Wang, Wanzhong; Bremell, Tomas; Josefsson, Elisabet; Jin, Tao

    2013-09-01

    Skin infections are frequently caused by Staphylococcus aureus and can lead to a fatal sepsis. The microbial mechanisms controlling the initiation and progression from mild skin infection to a severe disseminated infection remain poorly understood. Using a combination of clinical data and in vitro and ex vivo assays, we show that staphylokinase, secreted by S. aureus, promoted the establishment of skin infections in humans and increased bacterial penetration through skin barriers by activating plasminogen. However, when infection was established, the interaction between staphylokinase and plasminogen did not promote systemic dissemination but induced the opening and draining of abscesses and decreased disease severity in neutropenic mice. Also, increased staphylokinase production was associated with noninvasive S. aureus infections in patients. Our results point out the dual roles of staphylokinase in S. aureus skin infections as promoting the establishment of infections while decreasing disease severity.

  5. Wound infection kinetics probed by MALDI-MS: rapid profiling of Staphylococcus aureus in mice.

    PubMed

    Narayana, Jayaram Lakshmaiah; Gopal, Judy; Wu, Hui-Fen

    2012-07-21

    Using direct matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS), we were able to investigate the role of the clinically important bacteria, Staphylococcus aureus, in wound infections using mice. The infection kinetics of S. aureus at the wound site and the host immune response has been investigated using MALDI-MS. In this study, for the first time, we report the growth pattern of S. aureus infection at a wound site. Using mice wound infection models; the following study fingerprints the bacterial-host (mice) response at the wound site as a function of increasing wound infection in order to establish the infection pattern of Staphylococcus aureus in wounds. The current approach is extremely simple, rapid, highly selective, sensitive and established MALDI-MS as a versatile tool for detecting bacteria in clinical samples, such as those collected from wound sites.

  6. 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

  7. Staphylococcus aureus and Escherichia coli in nham (Thai-style fermented pork sausage).

    PubMed

    Petchsing, U; Woodburn, M J

    1990-05-01

    The fate of Staphylococcus aureus and Escherichia coli was determined when they were introduced into ground pork made into nham (Thai-style fermented pork sausage) with or without 0.75 or 1.5% added starter culture. Without starter culture, the numbers of E. coli remained little changed but there was slow multiplication of S. aureus. With 0.75% starter culture, S. aureus was no longer detectable after 48 h and E. coli numbers decreased by 1 log after 96 h. No viable S. aureus or E. coli were recovered after 36 h and 96 h, respectively, when 1.5% starter culture was added. The addition of a starter culture is recommended when making nham.

  8. Chemical composition of fennel essential oil and its impact on Staphylococcus aureus exotoxin production.

    PubMed

    Qiu, Jiazhang; Li, Hongen; Su, Hongwei; Dong, Jing; Luo, Mingjing; Wang, Jianfeng; Leng, Bingfeng; Deng, Yanhong; Liu, Juxiong; Deng, Xuming

    2012-04-01

    In this study, fennel oil was isolated by hydrodistillation, and the chemical composition was determined by gas chromatography/mass spectral analysis. The antimicrobial activity of fennel oil against Staphylococcus aureus was evaluated by broth microdilution. A haemolysis assay, tumour necrosis factor (TNF) release assay, western blot, and real-time reverse transcription (RT)-PCR were applied to investigate the influence of fennel oil on the production of S. aureus virulence-related exoproteins. The data show that fennel oil, which contains a high level of trans-anethole, was active against S. aureus, with MICs ranging from 64 to 256 μg/ml. Furthermore, fennel oil, when used at subinhibitory concentrations, could dose-dependently decrease the expression of S. aureus exotoxins, including α-toxin, Staphylococcal enterotoxins (SEs) and toxic shock syndrome toxin 1 (TSST-1).

  9. The giant protein Ebh is a determinant of Staphylococcus aureus cell size and complement resistance.

    PubMed

    Cheng, Alice G; Missiakas, Dominique; Schneewind, Olaf

    2014-03-01

    Staphylococcus aureus USA300, the clonal type associated with epidemic community-acquired methicillin-resistant S. aureus (MRSA) infections, displays the giant protein Ebh on its surface. Mutations that disrupt the ebh reading frame increase the volume of staphylococcal cells and alter the cross wall, a membrane-enclosed peptidoglycan synthesis and assembly compartment. S. aureus ebh variants display increased sensitivity to oxacillin (methicillin) as well as susceptibility to complement-mediated killing. Mutations in ebh are associated with reduced survival of mutant staphylococci in blood and diminished virulence in mice. We propose that Ebh, following its secretion into the cross wall, contributes to the characteristic cell growth and envelope assembly pathways of S. aureus, thereby enabling complement resistance and the pathogenesis of staphylococcal infections.

  10. Fine-structure molecular epidemiological analysis of Staphylococcus aureus recovered from cows.

    PubMed Central

    Fitzgerald, J. R.; Meaney, W. J.; Hartigan, P. J.; Smyth, C. J.; Kapur, V.

    1997-01-01

    Sixty-three Staphylococcus aureus isolates recovered from bovine sources in the USA and the Republic of Ireland were characterized by multilocus enzyme electrophoresis (MLEE), ribotyping, and random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) typing at two separate laboratories. The S. aureus isolates were assigned by MLEE to 10 electrophoretic types (ETs) (Index of Discrimination, D = 0.779). In contrast, the same isolates were assigned to 13 ribotypes (D = 0.888), and to 12 RAPD types (D = 0.898). A common clone, ET3, of worldwide distribution, was represented by six distinct combinations of ribotypes and RAPD types. S. aureus clones recovered from cows in Ireland were also associated with mastitis in dairy cows in the USA. These findings are consistent with the hypothesis that only a few specialized clones of S. aureus are responsible for the majority of cases of bovine mastitis, and that these clones have a broad geographic distribution. PMID:9363026

  11. Cross reactivity of S. aureus to murine cytokine assays: A source of discrepancy.

    PubMed

    Javed, Numan; Xue, Guang; Lu, Ailing; Xing, Yue; Iwakura, Yoichiro; Xiao, Hui; Lecoeur, Hervé; Späth, Gerald F; Meng, Guangxun

    2016-05-01

    Staphylococcus aureus is one of the versatile Gram positive bacteria causing a range of diseases. Upon challenge, host immune cells recognize S. aureus and mount diverse immune responses including production of pro-inflammatory cytokines such as IL-1β and TNF-α. These cytokines are important mediators of inflammation which can be detected via various immunological methods such as enzyme linked immunosorbent assay (ELISA) and immunoblotting. In the current study, we found that a number of clinical isolates as well as laboratory strains of S. aureus exhibited cross reactivity with ELISA antibodies for murine IL-1β and TNF-α assays. This cross reactivity generates exaggerated false positive signals which can be a source of discrepancy for the understanding of real immune responses against S. aureus infection by host immune cells.

  12. Staphylococcus aureus MnhF Mediates Cholate Efflux and Facilitates Survival under Human Colonic Conditions

    PubMed Central

    Sannasiddappa, Thippeswamy H.; Hood, Graham A.; Hanson, Kevan J.; Costabile, Adele; Gibson, Glenn R.

    2015-01-01

    Resistance to the innate defenses of the intestine is crucial for the survival and carriage of Staphylococcus aureus, a common colonizer of the human gut. Bile salts produced by the liver and secreted into the intestines are one such group of molecules with potent antimicrobial activity. The mechanisms by which S. aureus is able to resist such defenses in order to colonize and survive in the human gut are unknown. Here we show that mnhF confers resistance to bile salts, which can be abrogated by efflux pump inhibitors. MnhF mediates the efflux of radiolabeled cholic acid both in S. aureus and when heterologously expressed in Escherichia coli, rendering them resistant. Deletion of mnhF attenuated the survival of S. aureus in an anaerobic three-stage continuous-culture model of the human colon (gut model), which represents different anatomical areas of the large intestine. PMID:25824834

  13. Occurence and antimicrobial resistance of Staphylococcus aureus and Salmonella spp. in retail fish samples in Turkey.

    PubMed

    Ertas Onmaz, Nurhan; Abay, Secil; Karadal, Fulden; Hizlisoy, Harun; Telli, Nihat; Al, Serhat

    2015-01-15

    The aims of this study were to investigate the presence of Staphylococcus aureus and staphylococcal enterotoxins, as well as Salmonella spp. and to determine the antimicrobial susceptibilities of the isolates from fish samples. A total of 100 fish samples were analysed consisting of 30 anchovy, 35 trout and 35 sea bream. The presence of SEs was detected using ELISA and its genes confirmed by mPCR. Also, S. aureus and Salmonella spp. were detected in 9 (9%) and 5 (5%) samples, respectively. None of the S. aureus isolates had SEs and SEs genes. The resistance rates of the S. aureus isolates to erythromycin, tetracycline, and penicillin G were found to be 33% while Salmonella spp. isolates were resistant to trimethoprim-sulfamethoxazole, gentamicin and neomycine in 20%, 20% and 80%, respectively of the samples. It is of utmost important for public health that retail fish markets need to use hygienic practices in handling and processing operations.

  14. [Quantitative specific detection of Staphylococcus aureus based on recombinant lysostaphin and ATP bioluminescence].

    PubMed

    Li, Yuyuan; Mi, Zhiqiang; An, Xiaoping; Zhou, Yusen; Tong, Yigang

    2014-08-01

    Quantitative specific detection of Staphylococcus aureus is based on recombinant lysostaphin and ATP bioluminescence. To produce recombinant lysostaphin, the lysostaphin gene was chemically synthesized and inserted it into prokaryotic expression vector pQE30, and the resulting expression plasmid pQE30-Lys was transformed into E. coli M15 for expressing lysostaphin with IPTG induction. The recombinant protein was purified by Ni(2+)-NTA affinity chromatography. Staphylococcus aureus was detected by the recombinant lysostaphin with ATP bioluminescence, and plate count method. The results of the two methods were compared. The recombinant lysostaphin was successfully expressed, and a method of quantitative specific detection of S. aureus has been established, which showed a significant linear correlation with the colony counting. The detection method developed has good perspective to quantify S. aureus.

  15. Secreted Proteases Control Autolysin-mediated Biofilm Growth of Staphylococcus aureus*

    PubMed Central

    Chen, Chen; Krishnan, Vengadesan; Macon, Kevin; Manne, Kartik; Narayana, Sthanam V. L.; Schneewind, Olaf

    2013-01-01

    Staphylococcus epidermidis, a commensal of humans, secretes Esp protease to prevent Staphylococcus aureus biofilm formation and colonization. Blocking S. aureus colonization may reduce the incidence of invasive infectious diseases; however, the mechanism whereby Esp disrupts biofilms is unknown. We show here that Esp cleaves autolysin (Atl)-derived murein hydrolases and prevents staphylococcal release of DNA, which serves as extracellular matrix in biofilms. The three-dimensional structure of Esp was revealed by x-ray crystallography and shown to be highly similar to that of S. aureus V8 (SspA). Both atl and sspA are necessary for biofilm formation, and purified SspA cleaves Atl-derived murein hydrolases. Thus, S. aureus biofilms are formed via the controlled secretion and proteolysis of autolysin, and this developmental program appears to be perturbed by the Esp protease of S. epidermidis. PMID:23970550

  16. Staphylococcus aureus and CCR5: unveiling commonalities in host–pathogen interactions and potential treatment strategies

    PubMed Central

    Alonzo, Francis

    2014-01-01

    Microbes that have acquired the ability to colonize and/or cause disease in humans must be able to both recognize and respond to host defenses to ensure their survival. For commensal microbes, adaptive strategies generally promote a balance between host immune defenses and bacterial maintenance, allowing asymptomatic colonization. Pathogenic microbes, on the other hand, tilt the balance in favor of the microorganism, leading to symptomatic illness and disease. Some microorganisms that are known to be asymptomatic colonizers of humans can cause serious disease upon gaining access to foreign sites and usurping immunological attack. The Gram-positive bacterium Staphylococcus aureus is one such microorganism. This article will address recent advances in our understanding of S. aureus immune evasion with an emphasis on immune cell targeting. The prospects of this targeting in terms of understanding the evolution of S. aureus as a pathogen as well as its implications for future anti-S. aureus therapeutics, will be discussed. PMID:23534355

  17. Sterilization of Staphylococcus Aureus by an Atmospheric Non-Thermal Plasma Jet

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohu; Hong, Feng; Guo, Ying; Zhang, Jing; Shi, Jianjun

    2013-05-01

    An atmospheric non-thermal plasma jet was developed for sterilizing the Staphylococcus aureus (S. aureus). The plasma jet was generated by dielectric barrier discharge (DBD), which was characterized by electrical and optical diagnostics. The survival curves of the bacteria showed that the plasma jet could effectively inactivate 106 cells of S. aureus within 120 seconds and the sterilizing efficiency depended critically on the discharge parameter of the applied voltage. It was further confirmed by scanning electron microscopy (SEM) that the cell morphology was seriously damaged by the plasma treatment. The plasma sterilization mechanism of S. aureus was attributed to the active species of OH, N2+ and O, which were generated abundantly in the plasma jet and characterized by OES. Our findings suggest a convenient and low-cost way for sterilization and inactivation of bacteria.

  18. Performance of CHROMagar Staph aureus and CHROMagar MRSA for detection of Staphylococcus aureus in seawater and beach sand--comparison of culture, agglutination, and molecular analyses.

    PubMed

    Goodwin, K D; Pobuda, M

    2009-11-01

    Beach seawater and sand were analyzed for Staphylococcus aureus and methicillin resistant S. aureus (MRSA) for samples collected from Avalon, and Doheny Beach, CA. Membrane filtration followed by incubation on CHROMagar Staph aureus (SCA) and CHROMagar MRSA (C-MRSA) was used to enumerate S. aureus and MRSA, respectively. Media performance was evaluated by comparing identification via colony morphology and latex agglutination tests to PCR (clfA, 16S, and mecA genes). Due to background color and crowding, picking colonies from membrane filters and streaking for isolation were sometimes necessary. The specificity of SCA and C-MRSA was improved if colony isolates were identified by the presence of a matte halo in addition to mauve color; however routine agglutination testing of isolates did not appear warranted. Using the appearance of a colony on the membrane filter in conjunction with isolate appearance, the positive % agreement, the negative % agreement, and the % positive predictive accuracy for SCA was 84%, 95%, and 99% respectively, and for C-MRSA it was 85%, 98%, and 92%, respectively. Sensitivity and specificity of SCA and C-MRSA with membrane-filtered beach samples were optimized through identification experience, control of filter volume and incubation time, and isolation of colonies needing further identification. With optimization, SCA and C-MRSA could be used for enumeration of S. aureus and MRSA from samples of beach water and sand. For the sites studied here, the frequency of detection of S. aureus ranged from 60 to 76% and 53 to 79% for samples of beach seawater and sand, respectively. The frequency of detection of MRSA ranged from 2 to 9% and 0 to 12% for samples of seawater and sand, respectively.

  19. Comparative genomic analysis of Staphylococcus aureus FORC_001 and S. aureus MRSA252 reveals the characteristics of antibiotic resistance and virulence factors for human infection.

    PubMed

    Lim, Sooyeon; Lee, Dong-Hoon; Kwak, Woori; Shin, Hakdong; Ku, Hye-Jin; Lee, Jong-Eun; Lee, Gun Eui; Kim, Heebal; Choi, Sang-Ho; Ryu, Sangryeol; Lee, Ju-Hoon

    2015-01-01

    Staphylococcus aureus is an important foodborne pathogen that causes diverse diseases ranging from minor infections to life-threatening conditions in humans and animals. To further understand its pathogenesis, the genome of the strain S. aureus FORC_001 was isolated from a contaminated food. Its genome consists of 2,886,017 bp double-stranded DNA with a GC content of 32.8%. It is predicted to contain 2,728 open reading frames, 57 tRNAs, and 6 rRNA operons, including 1 additional 5S rRNA gene. Comparative phylogenetic tree analysis of 40 complete S. aureus genome sequences using average nucleotide identity (ANI) revealed that strain FORC_001 belonged to Group I. The closest phylogenetic match was S. aureus MRSA252, according to a whole-genome ANI (99.87%), suggesting that they might share a common ancestor. Comparative genome analysis of FORC_001 and MRSA252 revealed two non-homologous regions: Regions I and II. The presence of various antibiotic resistance genes, including the SCCmec cluster in Region I of MRSA252, suggests that this strain might have acquired the SCCmec cluster to adapt to specific environments containing methicillin. Region II of both genomes contains prophage regions but their DNA sequence identity is very low, suggesting that the prophages might differ. This is the first report of the complete genome sequence of S. aureus isolated from a real foodborne outbreak in South Korea. This report would be helpful to extend our understanding about the genome, general characteristics, and virulence factors of S. aureus for further studies of pathogenesis, rapid detection, and epidemiological investigation in foodborne outbreak.

  20. Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Aruldass, Claira Arul; Masalamany, Santhana Raj Louis; Venil, Chidambaram Kulandaisamy; Ahmad, Wan Azlina

    2017-03-31

    Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K(+), and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.

  1. Chronic ethanol feeding increases the severity of Staphylococcus aureus skin infections by altering local host defenses.

    PubMed

    Parlet, Corey P; Kavanaugh, Jeffrey S; Horswill, Alexander R; Schlueter, Annette J

    2015-04-01

    Alcoholics are at increased risk of Staphylococcus aureus skin infection and serious sequelae, such as bacteremia and death. Despite the association between alcoholism and severe S. aureus skin infection, the impact of EtOH on anti-S. aureus cutaneous immunity has not been investigated in a model of chronic EtOH exposure. To test the hypothesis that EtOH enhances the severity of S. aureus skin infection, mice were fed EtOH for ≥12 weeks via the Meadows-Cook model of alcoholism and inoculated with S. aureus following epidermal abrasion. Evidence of exacerbated staphylococcal disease in EtOH-fed mice included: skin lesions that were larger and contained more organisms, greater weight loss, and increased bacterial dissemination. Infected EtOH-fed mice demonstrated poor maintenance and induction of PMN responses in skin and draining LNs, respectively. Additionally, altered PMN dynamics in the skin of these mice corresponded with reduced production of IL-23 and IL-1β by CD11b(+) myeloid cells and IL-17 production by γδ T cells, with the latter defect occurring in the draining LNs as well. In addition, IL-17 restoration attenuated S. aureus-induced dermatopathology and improved bacterial clearance defects in EtOH-fed mice. Taken together, the findings show, in a novel model system, that the EtOH-induced increase in S. aureus-related injury/illness corresponds with defects in the IL-23/IL-17 inflammatory axis and poor PMN accumulation at the site of infection and draining LNs. These findings offer new information about the impact of EtOH on cutaneous host-defense pathways and provide a potential mechanism explaining why alcoholics are predisposed to S. aureus skin infection.

  2. Management of community-associated methicillin-resistant Staphylococcus aureus skin abscesses in children

    PubMed Central

    Robinson, Joan L; Salvadori, Marina I

    2011-01-01

    Uncomplicated skin abscesses in previously well children are typically managed with drainage alone. An increasing percentage of such abscesses are due to methicillin-resistant Staphylococcus aureus infections. Although definitive data are lacking, drainage alone appears to be a reasonable strategy for methicillin-resistant S aureus skin abscesses, with antibiotics reserved for infants younger than three months of age, or for children who are systemically unwell, have underlying medical problems or have significant surrounding cellulitis. PMID:22294871

  3. Transfer and Decontamination of S. aureus in Transmission Routes Regarding Hands and Contact Surfaces

    PubMed Central

    Arinder, Pernilla; Johannesson, Pär; Karlsson, Ingela; Borch, Elisabeth

    2016-01-01

    Hand hygiene, cleaning and disinfection are pre-requirements for hygiene management in hospital settings and the food industry. In order to facilitate risk management, different contamination scenarios and interventions need to be evaluated. In the present study data on transfer rates and reductions of Staphylococcus aureus were provided in an experimental set-up using artificial skin. Using this methodology, test persons were not exposed with pathogenic bacteria. An exposure assessment model was developed and applied to evaluate different contamination routes and hygiene interventions. The transfer rates of S. aureus from inoculated VITRO-SKIN® to fomites were calculated from blotting series. The VITRO-SKIN® was more prone to spread bacteria than fomites. When different surfaces were cleaned, the reduction of S. aureus varied between <1 and 7 log CFU. It could not be concluded that a certain coupon material, cleaning agent, cleaning wipe, soiling or humidity consistently resulted in a high or low reduction of S. aureus. The reduction of S. aureus and E. coli during hand washing was evaluated on artificial skin, VITRO-SKIN®. The reduction of E. coli on VITRO-SKIN® was similar to the log reduction obtained when washing human hands. The S. aureus count on a human hand was both calculated in different scenarios describing different contamination routes starting from a contaminated hand using the exposure assessment model, and measured on an experimental setup using VITRO-SKIN® for validation. A linear relationship was obtained between the analysed level of S. aureus and the calculated level. However, the calculated levels of S. aureus on the VITRO-SKIN® in the scenarios were 1–1.5 log lower than the analysed level. One of the scenarios was used to study the effect of interventions like hand washing and cleaning of surfaces. PMID:27280772

  4. 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

  5. Understanding the rise of the superbug: investigation of the evolution and genomic variation of Staphylococcus aureus.

    PubMed

    Lindsay, Jodi A; Holden, Matthew T G

    2006-07-01

    The bacterium Staphylococcus aureus is a common cause of human infection, and it is becoming increasingly virulent and resistant to antibiotics. Our understanding of the evolution of this species has been greatly enhanced by the recent sequencing of the genomes of seven strains of S. aureus. Comparative genomic analysis allows us to identify variation in the chromosomes and understand the mechanisms by which this versatile bacterium has accumulated diversity within its genome structure.

  6. Acquired and Native Resistance of Staphylococcus aureus to Cephalexin and Other β-Lactam Antibiotics 1

    PubMed Central

    Kayser, Fritz H.; Benner, E. Jack; Hoeprich, Paul D.

    1970-01-01

    Staphylococcus aureus cells that are initially susceptible to cephalexin can be induced to acquire intrinsic resistance to cephalexin in comparatively few steps. Concomitantly, resistance to cephalothin, oxacillin, and dicloxacillin increases. By population analysis, there is heteroresistance to cephalexin in some strains of S. aureus. Heterogeneity in colonial morphology on prolonged incubation in the presence of subinhibitory concentrations of cephalexin may constitute an expression of such heteroresistance. Images PMID:5201887

  7. Transfer and Decontamination of S. aureus in Transmission Routes Regarding Hands and Contact Surfaces.

    PubMed

    Arinder, Pernilla; Johannesson, Pär; Karlsson, Ingela; Borch, Elisabeth

    2016-01-01

    Hand hygiene, cleaning and disinfection are pre-requirements for hygiene management in hospital settings and the food industry. In order to facilitate risk management, different contamination scenarios and interventions need to be evaluated. In the present study data on transfer rates and reductions of Staphylococcus aureus were provided in an experimental set-up using artificial skin. Using this methodology, test persons were not exposed with pathogenic bacteria. An exposure assessment model was developed and applied to evaluate different contamination routes and hygiene interventions. The transfer rates of S. aureus from inoculated VITRO-SKIN® to fomites were calculated from blotting series. The VITRO-SKIN® was more prone to spread bacteria than fomites. When different surfaces were cleaned, the reduction of S. aureus varied between <1 and 7 log CFU. It could not be concluded that a certain coupon material, cleaning agent, cleaning wipe, soiling or humidity consistently resulted in a high or low reduction of S. aureus. The reduction of S. aureus and E. coli during hand washing was evaluated on artificial skin, VITRO-SKIN®. The reduction of E. coli on VITRO-SKIN® was similar to the log reduction obtained when washing human hands. The S. aureus count on a human hand was both calculated in different scenarios describing different contamination routes starting from a contaminated hand using the exposure assessment model, and measured on an experimental setup using VITRO-SKIN® for validation. A linear relationship was obtained between the analysed level of S. aureus and the calculated level. However, the calculated levels of S. aureus on the VITRO-SKIN® in the scenarios were 1-1.5 log lower than the analysed level. One of the scenarios was used to study the effect of interventions like hand washing and cleaning of surfaces.

  8. Mannitol-negative methicillin-resistant Staphylococcus aureus from nasal swab specimens in Brazil

    PubMed Central

    dos Santos, Danielle Caldeira Martins; da Costa, Thaina Miranda; Rabello, Renata Fernandes; Alves, Fábio Aguiar; de Mondino, Silvia Susana Bona

    2015-01-01

    The isolation of mannitol-negative methicillin-resistant Staphylococcus aureus from nasal swabs is reported. Among the 59 isolates, 9 (15%) isolates were mannitol-negative; all of these isolates were categorized as staphylococcal cassette chromosome mec (SCCmec) type IVa. This report emphasizes that mannitol fermentation on mannitol salt agar should not be used as the sole criterion when screening nasal swab specimens for S. aureus. PMID:26273270

  9. Draft Genome Sequences of Burkholderia pseudomallei and Staphylococcus aureus, Isolated from a Patient with Chronic Rhinosinusitis

    PubMed Central

    Cottrell, Kyra; Cervin, Anders

    2015-01-01

    Here, we report the draft genome sequences of Burkholderia pseudomallei and Staphylococcus aureus causing chronic rhinosinusitis. Whole-genome sequencing determined the B. pseudomallei as sequence type (ST) 1381 and the S. aureus as ST8. B. pseudomallei possessed the blaOXA-59 gene. This study illustrates the potential emergence of B. pseudomallei in cases of chronic rhinosinusitis. PMID:26430027

  10. Carriage of Staphylococcus aureus in Thika Level 5 Hospital, Kenya: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen but little is known about its circulation in hospitals in developing countries. We aimed to describe carriage of S.aureus amongst inpatients in a mid-sized Kenyan government hospital. Methods We determined the frequency of S.aureus and MRSA carriage amongst inpatients in Thika Hospital, Kenya by means of repeated cross-sectional ward surveys. For all S.aureus isolates, we performed antibiotic susceptibility tests, genomic profiling using a DNA microarray and spa typing and MLST. Results In this typical mid-sized Kenyan Government hospital, we performed 950 screens for current carriage of S.aureus amongst inpatients over a four month period. We detected S.aureus carriage (either MSSA or MRSA) in 8.9% (85/950; 95%CI 7.1-10.8) of inpatient screens, but patients with multiple screens were more likely have detection of carriage. MRSA carriage was rare amongst S.aureus strains carried by hospital inpatients – only 7.0% (6/86; 95%CI 1.5-12.5%) of all isolates were MRSA. Most MRSA (5/6) were obtained from burns patients with prolonged admissions, who only represented a small proportion of the inpatient population. All MRSA strains were of the same clone (MLST ST239; spa type t037) with concurrent resistance to multiple antibiotic classes. MSSA isolates were diverse and rarely expressed antibiotic resistance except against benzyl-penicillin and co-trimoxazole. Conclusions Although carriage rates for S.aureus and the MRSA prevalence in this Kenyan hospital were both low, burns patient were identified as a high risk group for carriage. The high frequency of genetically indistinguishable isolates suggests that there was local transmission of both MRSA and MSSA. PMID:25057351

  11. Genetic relatedness and virulence factors of bovine Staphylococcus aureus isolated from teat skin and milk.

    PubMed

    da Costa, L B; Rajala-Schultz, P J; Hoet, A; Seo, K S; Fogt, K; Moon, B S

    2014-11-01

    The objective of this study was to assess the role of teat skin colonization in Staphylococcus aureus intramammary infections (IMI) by evaluating genetic relatedness of Staph. aureus isolates from milk and teat skin of dairy cows using pulsed-field gel electrophoresis and characterizing the isolates based on the carriage of virulence genes. Cows in 4 known Staph. aureus-positive herds were sampled and Staph. aureus was detected in 43 quarters of 20 cows, with 10 quarters positive in both milk and skin (20 isolates), 18 positive only in milk, and 15 only on teat skin. Quarters with teat skin colonized with Staph. aureus were 4.5 times more likely to be diagnosed with Staph. aureus IMI than quarters not colonized on teat skin. Three main clusters were identified by pulsed-field gel electrophoresis using a cutoff of 80% similarity. All 3 clusters included both milk and skin isolates. The majority of isolates (72%) belonged to one predominant cluster (B), with 60% of isolates in the cluster originating from milk and 40% from teat skin. Genotypic variability was observed within 10 pairs (formed by isolates originating from milk and teat skin of the same quarter), where isolates in 5 out of the 10 pairs belonged to the same cluster. Forty-two virulence factors were screened using PCR. Some virulence factors were carried more frequently by teat skin isolates than by milk isolates or isolates from quarters with high somatic cell counts. Isolates in the predominant cluster B carried virulence factors clfA and clfB significantly more often than isolates in the minor clusters, which may have assisted them in becoming predominant in the herds. The present findings suggest that teat skin colonization with Staph. aureus can be an important factor involved in Staph. aureus IMI.

  12. Staphylococcus aureus Protein A Mediates Interspecies Interactions at the Cell Surface of Pseudomonas aeruginosa

    PubMed Central

    Armbruster, Catherine R.; Wolter, Daniel J.; Mishra, Meenu; Hayden, Hillary S.; Radey, Matthew C.; Merrihew, Gennifer; MacCoss, Michael J.; Burns, Jane; Wozniak, Daniel J.

    2016-01-01

    ABSTRACT While considerable research has focused on the properties of individual bacteria, relatively little is known about how microbial interspecies interactions alter bacterial behaviors and pathogenesis. Staphylococcus aureus frequently coinfects with other pathogens in a range of different infectious diseases. For example, coinfection by S. aureus with Pseudomonas aeruginosa occurs commonly in people with cystic fibrosis and is associated with higher lung disease morbidity and mortality. S. aureus secretes numerous exoproducts that are known to interact with host tissues, influencing inflammatory responses. The abundantly secreted S. aureus staphylococcal protein A (SpA) binds a range of human glycoproteins, immunoglobulins, and other molecules, with diverse effects on the host, including inhibition of phagocytosis of S. aureus cells. However, the potential effects of SpA and other S. aureus exoproducts on coinfecting bacteria have not been explored. Here, we show that S. aureus-secreted products, including SpA, significantly alter two behaviors associated with persistent infection. We found that SpA inhibited biofilm formation by specific P. aeruginosa clinical isolates, and it also inhibited phagocytosis by neutrophils of all isolates tested. Our results indicate that these effects were mediated by binding to at least two P. aeruginosa cell surface structures—type IV pili and the exopolysaccharide Psl—that confer attachment to surfaces and to other bacterial cells. Thus, we found that the role of a well-studied S. aureus exoproduct, SpA, extends well beyond interactions with the host immune system. Secreted SpA alters multiple persistence-associated behaviors of another common microbial community member, likely influencing cocolonization and coinfection with other microbes. PMID:27222468

  13. Staphylococcus aureus hijacks a skin commensal to intensify its virulence: immunization targeting β-hemolysin and CAMP factor.

    PubMed

    Lo, Chih-Wei; Lai, Yiu-Kay; Liu, Yu-Tsueng; Gallo, Richard L; Huang, Chun-Ming

    2011-02-01

    The need for a new anti-Staphylococcus aureus therapy that can effectively cripple bacterial infection, neutralize secretory virulence factors, and lower the risk of creating bacterial resistance is undisputed. Here, we propose what is, to our knowledge, a previously unreported infectious mechanism by which S. aureus may commandeer Propionibacterium acnes, a key member of the human skin microbiome, to spread its invasion and highlight two secretory virulence factors (S. aureus β-hemolysin and P. acnes CAMP (Christie, Atkins, Munch-Peterson) factor) as potential molecular targets for immunotherapy against S. aureus infection. Our data demonstrate that the hemolysis and cytolysis by S. aureus were noticeably augmented when S. aureus was grown with P. acnes. The augmentation was significantly abrogated when the P. acnes CAMP factor was neutralized or β-hemolysin of S. aureus was mutated. In addition, the hemolysis and cytolysis of recombinant β-hemolysin were markedly enhanced by recombinant CAMP factor. Furthermore, P. acnes exacerbated S. aureus-induced skin lesions in vivo. The combination of CAMP factor neutralization and β-hemolysin immunization cooperatively suppressed the skin lesions caused by coinfection of P. acnes and S. aureus. These observations suggest a previously unreported immunotherapy targeting the interaction of S. aureus with a skin commensal.

  14. Is the Colonisation of Staphylococcus aureus in Pets Associated with Their Close Contact with Owners?

    PubMed Central

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

    2016-01-01

    In human beings and animals, staphylococci constitute part of the normal microbial population. Staphylococcus aureus could be classified as an opportunistic pathogen because the bacteria are noted in clinically healthy individuals, but when the immune system becomes compromised, they can also cause a wide range of infections. The objective of this study was to test the hypothesis that cats who are in close contact with their owners are at the greatest risk of being colonised with S. aureus. Two groups of cats were investigated: single, pet (domestic) cats that do not have outdoor access; and a local population of feral cats living in urban areas. The prevalence of S. aureus in domestic cats was 19.17%, while it’s prevalence in the feral cat population was only 8.3%; which was statistically significant. Analysis of antibiotic resistance, at the genotypic as well as phenotypic level, showed that S. aureus isolates from pet cats were more likely to harbour antibiotic resistant determinants. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in households was 10.21%, while in feral cats it was only 1.4%. In conclusion, this study has revealed a correlation between close contact with humans and a higher risk of the cats being colonised with S. aureus and harbouring the antibiotic resistant determinants. PMID:27227897

  15. Carriage of Staphylococcus aureus in the nose of patients on regular dialysis treatment using hemodialysis catheters.

    PubMed

    Maamoun, Hoda Abdel Hamid; Soliman, Amin Roshdy; El Sherif, Rasha

    2011-10-01

    In the hemodialysis population, the incidence of Staphylococcus aureus colonization has been documented to be as high as 80%; effective prophylaxis of vascular access infection and bacteremia is a worthwhile goal in the management of hemodialysis population. Surveillance of 50 hemodialysis patients for S. aureus-positive nasal cultures was performed by monthly nasal swabs over a 12-month period. All patients were performing dialysis using hemodialysis catheters thrice weekly. All positive cultures were treated with a prophylactic antibiotic regimen. Thirty-one patients (62%) had one or more positive cultures. The surveillance period was longer in the S. aureus nasal carriers (p < 0.01). The frequency of positive cultures correlated with the duration of surveillance (p < 0.05). The incidence of S. aureus bacteremia was greater in patients with three or more positive cultures (p < 0.05). This study suggests that continuous surveillance for S. aureus nasal colonization is essential to properly identify all hemodialysis patients using catheters at risk of developing S. aureus bacteremias.

  16. Epidemiology and antibiotic sensitivity of Staphylococcus aureus nasal carriage in children in Hungary.

    PubMed

    Laub, Krisztina; Tóthpál, Adrienn; Kardos, Szilvia; Dobay, Orsolya

    2017-02-21

    The aim of this study was to assess the Staphylococcus aureus nasal carriage rate in healthy children all over Hungary and to specify some risk factors, the antibiotic resistance patterns of the bacteria, and their genetic relatedness. In total, 878 children (aged 3-6 years) were screened at 21 day-care centers in 16 different cities in Hungary, between February 2009 and December 2011. Samples taken from both nostrils were cultured on blood agar, and suspected S. aureus isolates were identified by β-hemolysis, catalase positivity, clump test, and nucA PCR. Methicillin-resistant strains were screened by mecA and mecC PCR. Antibiotic susceptibility was determined by agar dilution or gradient test strips. Pulsed-field gel electrophoresis was used for genotyping. S. aureus carriage rate was found to be 21.3%, which correlates well with international data. We found no statistically significant correlation between the gender or the sibling status and S. aureus carriage. All isolates were sensitive to oxacillin, trimethoprim-sulfamethoxazole, and mupirocin. The resistance rates for erythromycin, ciprofloxacin, clindamycin, gentamicin, and tetracycline were 7.5%, 0.5%, 1.1%, 3.7%, and 4.3%, respectively. The isolates showed very high genetic diversity. In summary, carried S. aureus isolates are more sensitive to antibiotics compared with clinical isolates in Hungary, and methicillin-resistant S. aureus carriage rate is very low yet.

  17. Staphylococcus aureus Toxins and Diabetic Foot Ulcers: Role in Pathogenesis and Interest in Diagnosis

    PubMed Central

    Dunyach-Remy, Catherine; Ngba Essebe, Christelle; Sotto, Albert; Lavigne, Jean-Philippe

    2016-01-01

    Infection of foot ulcers is a common, often severe and costly complication in diabetes. Diabetic foot infections (DFI) are mainly polymicrobial, and Staphylococcus aureus is the most frequent pathogen isolated. The numerous virulence factors and toxins produced by S. aureus during an infection are well characterized. However, some particular features could be observed in DFI. The aim of this review is to describe the role of S. aureus in DFI and the implication of its toxins in the establishment of the infection. Studies on this issue have helped to distinguish two S. aureus populations in DFI: toxinogenic S. aureus strains (harboring exfoliatin-, EDIN-, PVL- or TSST-encoding genes) and non-toxinogenic strains. Toxinogenic strains are often present in infections with a more severe grade and systemic impact, whereas non-toxinogenic strains seem to remain localized in deep structures and bone involving diabetic foot osteomyelitis. Testing the virulence profile of bacteria seems to be a promising way to predict the behavior of S. aureus in the chronic wounds. PMID:27399775

  18. Identification of Infantile Diarrhea Caused by Breast Milk-Transmitted Staphylococcus aureus Infection.

    PubMed

    Chen, Zhong; Pan, Wei-Guang; Xian, Wei-Yi; Cheng, Hang; Zheng, Jin-Xin; Hu, Qing-Hua; Yu, Zhi-Jian; Deng, Qi-Wen

    2016-10-01

    Staphylococcus aureus is a well-known organism which is responsible for a variety of human infectious diseases including skin infections, pneumonia, bacteremia, and endocarditis. Few of the microorganisms can be transmitted from mother to the newborn or infant by milk breastfeeding. This study aims to identify transmission of S. aureus from healthy, lactating mothers to their infants by breastfeeding. Stool specimens of diarrheal infants and breast milk of their mother (totally three pairs) were collected and six Staphylococcus aureus isolates were cultured positively. Homology and molecular characters of isolated strains were tested using pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing. Furthermore, toxin genes detection was also performed. Each pair of isolates has the same PFGE type and spa type. Four Sequence types (STs) were found among all the isolates; they are ST15, ST188, and ST59, respectively. Among the strains, seb, sec, and tst genes were found, and all were negative for pvl gene. The homology of the S. aureus strains isolated from the infants' stool and the mothers' milk was genetically demonstrated, which indicated that breastfeeding may be important in the transmission of S. aureus infection, and the character of S. aureus needed to be further evaluated.

  19. Staphylococcus aureus forms spreading dendrites that have characteristics of active motility

    PubMed Central

    Pollitt, Eric J. G.; Crusz, Shanika A.; Diggle, Stephen P.

    2015-01-01

    Staphylococcus aureus is historically regarded as a non-motile organism. More recently it has been shown that S. aureus can passively move across agar surfaces in a process called spreading. We re-analysed spreading motility using a modified assay and focused on observing the formation of dendrites: branching structures that emerge from the central colony. We discovered that S. aureus can spread across the surface of media in structures that we term ‘comets’, which advance outwards and precede the formation of dendrites. We observed comets in a diverse selection of S. aureus isolates and they exhibit the following behaviours: (1) They consist of phenotypically distinct cores of cells that move forward and seed other S. aureus cells behind them forming a comet ‘tail’; (2) they move when other cells in the comet tail have stopped moving; (3) the comet core is held together by a matrix of slime; and (4) the comets etch trails in the agar as they move forwards. Comets are not consistent with spreading motility or other forms of passive motility. Comet behaviour does share many similarities with a form of active motility known as gliding. Our observations therefore suggest that S. aureus is actively motile under certain conditions. PMID:26680153

  20. Incidence of Staphylococcus aureus and Analysis of Associated Bacterial Communities on Food Industry Surfaces

    PubMed Central

    Gutiérrez, Diana; Delgado, Susana; Vázquez-Sánchez, Daniel; Martínez, Beatriz; Cabo, Marta López; Rodríguez, Ana; Herrera, Juan J.

    2012-01-01

    Biofilms are a common cause of food contamination with undesirable bacteria, such as pathogenic bacteria. Staphylococcus aureus is one of the major bacteria causing food-borne diseases in humans. A study designed to determine the presence of S. aureus on food contact surfaces in dairy, meat, and seafood environments and to identify coexisting microbiota has therefore been carried out. A total of 442 samples were collected, and the presence of S. aureus was confirmed in 6.1% of samples. Sixty-three S. aureus isolates were recovered and typed by random amplification of polymorphic DNA (RAPD). Profiles were clustered into four groups which were related to specific food environments. All isolates harbored some potential virulence factors such as enterotoxin production genes, biofilm formation-associated genes, antibiotic resistance, or lysogeny. PCR-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprints of bacterial communities coexisting with S. aureus revealed the presence of bacteria either involved in food spoilage or of concern for food safety in all food environments. Food industry surfaces could thus be a reservoir for S. aureus forming complex communities with undesirable bacteria in multispecies biofilms. Uneven microbiological conditions were found in each food sector, which indicates the need to improve hygienic conditions in food processing facilities, particularly the removal of bacterial biofilms, to enhance the safety of food products. PMID:23023749

  1. Community-associated methicillin-resistant Staphylococcus aureus in non-outbreak skin infections.

    PubMed

    Bonesso, Mariana Fávero; Marques, Silvio Alencar; Camargo, Carlos Henrique; Fortaleza, Carlos Magno Castelo Branco; da Cunha, Maria de Lourdes Ribeiro de Souza

    2014-01-01

    The aim of this study was to determine the prevalence of Staphylococcus aureus and risk factors for the acquisition of MRSA (Methicillin Resistant Staphylococcus aureus) as the main cause of skin and soft tissue infections. S. aureus were characterized for the presence of PVL, TSST-1 and mecA genes. SCCmec typing was carried out in mecA positive strains and PFGE was performed only in these strains. During the study period, 127 outpatients attending a dermatology clinical the Botucatu Medical School, a regional tertiary hospital in Botucatu, Sao Paulo, Brazil, were diagnosed with active skin infections. A total 66 (56.9%) S. aureus strains were isolated. The methicillin resistance gene mecA was detected in seven (10.6%) S. aureus strains. The SCCmec types detected in the seven mecA-positive S. aureus strains were type Ia in one, type II in three, and type IV in three. The PVL gene was detected in 10 (15.1%) in sensitive strains. Pulsed field gel electrophoresis revealed non-clonal diversity among the isolates. The risk factors associated with MRSA acquisition in this study were previous ciprofloxacin use and working in a healthcare environment. The risk factors indicate plausible routes of CA-MRSA transmission among the subjects studied.

  2. Susceptibility of Staphylococcus aureus bacteremia strains to different skin-derived antimicrobial proteins.

    PubMed

    Köten, Bente; Becker, Karsten; Podschun, Rainer; von Eiff, Christof; Meyer-Hoffert, Ulf; Harder, Jürgen; Gläser, Regine

    2012-10-01

    Staphylococcus aureus is a major human pathogen causing cutaneous infections to life-threatening