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Sample records for positive staphylococcus aureus

  1. 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

  2. Characterization of coagulase-positive Staphylococcus intermedius and Staphylococcus aureus isolated from veterinary clinical specimens.

    PubMed

    Raus, J; Love, D N

    1983-10-01

    Staphylococci were the most frequent isolates from clinical specimens submitted from a large referral and teaching veterinary hospital. In this study a total of 160 isolates were examined by a wide range of biochemical tests and modifications of basic procedures. An attempt was made to test the validity of these procedures for use in characterization of clinical isolates of coagulase-positive staphylococci. Of the isolates examined, some 27 were Staphylococcus aureus, 115 were Staphylococcus intermedius, and the rest were coagulase-negative staphylococci and were not characterized further. The most useful discriminatory tests were acid production from maltose incubated overnight on maltose purple agar (W. E. Kloos and K. H. Schleifer, J. Clin. Microbiol., 1:82-88, 1975), acetoin production detected by the Barritt method, and detection of hyaluronidase activity. These gave accurate and fast results. Supplemented with the tellurite reduction test and the direct staphylocoagulase assay using Chromozym TH (Engels et al.; J. Clin. Microbiol. 14:496-500, 1981), these tests should eliminate the possibility of false identifications of these two species.

  3. Characterization of coagulase-positive Staphylococcus intermedius and Staphylococcus aureus isolated from veterinary clinical specimens.

    PubMed Central

    Raus, J; Love, D N

    1983-01-01

    Staphylococci were the most frequent isolates from clinical specimens submitted from a large referral and teaching veterinary hospital. In this study a total of 160 isolates were examined by a wide range of biochemical tests and modifications of basic procedures. An attempt was made to test the validity of these procedures for use in characterization of clinical isolates of coagulase-positive staphylococci. Of the isolates examined, some 27 were Staphylococcus aureus, 115 were Staphylococcus intermedius, and the rest were coagulase-negative staphylococci and were not characterized further. The most useful discriminatory tests were acid production from maltose incubated overnight on maltose purple agar (W. E. Kloos and K. H. Schleifer, J. Clin. Microbiol., 1:82-88, 1975), acetoin production detected by the Barritt method, and detection of hyaluronidase activity. These gave accurate and fast results. Supplemented with the tellurite reduction test and the direct staphylocoagulase assay using Chromozym TH (Engels et al.; J. Clin. Microbiol. 14:496-500, 1981), these tests should eliminate the possibility of false identifications of these two species. PMID:6630462

  4. 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.

  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. 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.

  7. Molecular Epidemiology Survey of Staphylococcus aureus Panton-Valentine Leukocidin-positive Isolated from Sanandaj, Iran.

    PubMed

    Manafi, Abbas; Khodabandehloo, Mazaher; Rouhi, Samaneh; Ramazanzadeh, Rashid; Shahbazi, Babak; Narenji, Hanar

    2017-01-01

    Staphylococcus aureus strains that are Panton-Valentine leukocidin (PVL) positive cause severe skin and soft tissue infections as well as necrotizing pneumonia. The presence of PVL gene is a marker for methicillin-resistant S. aureus; therefore, survey on prevalence and phylogenetic distribution of PVL is of great importance for public health. The aim of this research was molecular epidemiology survey of S. aureus PVL positive, isolated from two tertiary hospitals of Sanandaj. A total of 264 staphylococci isolates were collected from clinical specimens, hospital personnel and hospital environment of two tertiary hospitals of Sanandaj, in 2012 (Toohid and Besat). Bacterial cultures and biochemical tests were performed for S. aureus detection. Then, polymerase chain reaction (PCR) and repetitive sequence-based PCR (rep-PCR) were used for the determination of prevalence and molecular epidemiology of S. aureus PVL, respectively. Data were analyzed using the Fisher's exact test (P < 0.05). From 264 staphylococci isolates, 88 (33.33%) were detected as S. aureus. Furthermore, 20 out of 88 (22.72%) strains of S. aureus were PVL positive according to PCR results. Rep-PCR showed six main clusters of S. aureus samples. PVL had similar clonality between different samples. No significant relationship was observed between PVL positive S. aureus and rep-PCR patterns (P = 0.98). These results showed that a clone of S. aureus PVL positive has spread between the community and hospital settings. Therefore, appropriate measures are required to prevent the spread of staphylococci and other bacteria in hospitals.

  8. Staphylococcus aureus and Pregnancy

    MedlinePlus

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

  9. Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles

    PubMed Central

    Romero-Urbina, Dulce G; Lara, Humberto H; Velázquez-Salazar, J Jesús; Arellano-Jiménez, M Josefina; Larios, Eduardo; Srinivasan, Anand; Lopez-Ribot, Jose L

    2015-01-01

    Summary Silver nanoparticles offer a possible means of fighting antibacterial resistance. Most of their antibacterial properties are attributed to their silver ions. In the present work, we study the actions of positively charged silver nanoparticles against both methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. We use aberration-corrected transmission electron microscopy to examine the bactericidal effects of silver nanoparticles and the ultrastructural changes in bacteria that are induced by silver nanoparticles. The study revealed that our 1 nm average size silver nanoparticles induced thinning and permeabilization of the cell wall, destabilization of the peptidoglycan layer, and subsequent leakage of intracellular content, causing bacterial cell lysis. We hypothesize that positively charged silver nanoparticles bind to the negatively charged polyanionic backbones of teichoic acids and the related cell wall glycopolymers of bacteria as a first target, consequently stressing the structure and permeability of the cell wall. This hypothesis provides a major mechanism to explain the antibacterial effects of silver nanoparticles on Staphylococcus aureus. Future research should focus on defining the related molecular mechanisms and their importance to the antimicrobial activity of silver nanoparticles. PMID:26734530

  10. Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles.

    PubMed

    Romero-Urbina, Dulce G; Lara, Humberto H; Velázquez-Salazar, J Jesús; Arellano-Jiménez, M Josefina; Larios, Eduardo; Srinivasan, Anand; Lopez-Ribot, Jose L; Yacamán, Miguel José

    2015-01-01

    Silver nanoparticles offer a possible means of fighting antibacterial resistance. Most of their antibacterial properties are attributed to their silver ions. In the present work, we study the actions of positively charged silver nanoparticles against both methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. We use aberration-corrected transmission electron microscopy to examine the bactericidal effects of silver nanoparticles and the ultrastructural changes in bacteria that are induced by silver nanoparticles. The study revealed that our 1 nm average size silver nanoparticles induced thinning and permeabilization of the cell wall, destabilization of the peptidoglycan layer, and subsequent leakage of intracellular content, causing bacterial cell lysis. We hypothesize that positively charged silver nanoparticles bind to the negatively charged polyanionic backbones of teichoic acids and the related cell wall glycopolymers of bacteria as a first target, consequently stressing the structure and permeability of the cell wall. This hypothesis provides a major mechanism to explain the antibacterial effects of silver nanoparticles on Staphylococcus aureus. Future research should focus on defining the related molecular mechanisms and their importance to the antimicrobial activity of silver nanoparticles.

  11. Staphylococcus aureus toxins.

    PubMed

    Otto, Michael

    2014-02-01

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

  12. Molecular characteristics of bap-positive Staphylococcus aureus strains from dairy cow mastitis.

    PubMed

    Snel, Gustavo G M; Monecke, Stefan; Ehricht, Ralf; Piccinini, Renata

    2015-08-01

    The biofilm-associated protein (Bap) of Staphylococcus aureus is a high molecular weight cell-wall-anchored protein involved in biofilm formation, first described in bovine mastitis strains from Spain. So far, studies regarding Bap were mainly based on the Spanish strain V329 and its mutants, but no information on the genetic variability of bap-positive Staph. aureus strains is yet available in the literature. The present study investigated the molecular characteristics of 8 bap-positive Staph. aureus strains from subclinical bovine mastitis, isolated in 5 herds; somatic cell counts (SCC) of milk samples were also registered. Strains were characterised using MLST, SPA typing and microarray and the results were compared with V329. All isolates from this study and V329 were assigned to ST126, t605, but some molecular differences were observed. Only herd A and B strains harboured the genes for β-lactams resistance; the leukocidin D/E gene, a type I site-specific deoxyribonuclease subunit, 3rd locus gene and serin-protease A and B were carried by all strains, but not by V329, while serin-protease E was absent in V329 and in another isolate. Four isolates and V329 harboured the fibronectin-binding protein B gene. SCC showed the highest value in the milk sample affected by the only strain carrying all the virulence factors considered. Potential large variability of virulence was evidenced among V329 and all bap-positive Staph. aureus strains considered: the carriage of fnb could enhance the accumulation of biofilm, but the lack of lukD/E and splA, B or E might decrease the invasiveness of strain.

  13. Staphylococcus aureus in rural drinking water.

    PubMed Central

    LeChevallier, M W; Seidler, R J

    1980-01-01

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

  14. Alternative Use for Spectra MRSA Chromogenic Agar in Detection of Methicillin-Resistant Staphylococcus aureus from Positive Blood Cultures ▿

    PubMed Central

    Peterson, Jess F.; Dionisio, Alexander A.; Riebe, Katherine M.; Hall, Gerri S.; Wilson, Deborah A.; Whittier, Susan; DiPersio, Joseph R.; Ledeboer, Nathan A.

    2010-01-01

    Spectra MRSA agar (Remel, Lenexa, KS), a novel chromogenic medium originally developed to detect methicillin-resistant Staphylococcus aureus (MRSA) from nasal swabs, was evaluated in this multicenter study for the detection of MRSA from positive blood cultures exhibiting Gram-positive cocci upon initial Gram staining. PMID:20392925

  15. 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.

  16. 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

  17. Double triplex real-time PCR assay for simultaneous detection of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus haemolyticus and determination of their methicillin resistance directly from positive blood culture bottles.

    PubMed

    Kilic, Abdullah; Basustaoglu, A Celal

    2011-12-01

    We developed and validated here a double triplex real-time PCR assay to simultaneously detect and identify Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus and their methicillin resistance in a single reaction directly from Gram-positive cocci-in-clusters (GPCs)-positive blood culture bottles. From August 15, 2009 through February 15, 2010, 238 GPC-positive samples were collected and identified by conventional methods as 11 methicillin-resistant S. aureus (MRSA), 28 methicillin-susceptible S. aureus (MSSA), 176 MR coagulase-negative staphylococci (MRCoNS), 21 MSCoNS and two Enterococcus faecalis. The double triplex real-time PCR assay was targeted and detected tuf, nuc and mecA genes in the first tube and atlE, gap and mvaA genes in the second tube which could be run simultaneously. The detection limit of the assay was found at 10(3) CFU/ml for the atleE gene, 10(4) CFU/ml for the mva gene and 10(5) CFU/ml for gap, nuc, mecA and tuf genes based on seeding experiments. All Staphylococcus species except two S. epidermidis were correctly identified by the assay. The double triplex real-time PCR assay quickly and accurately detects S. aureus, S. epidermidis, S. hominis and S. haemolyticus and their methicillin resistance in a single reaction directly from positive blood culture bottles within 83 min.

  18. [Identification and characterization of Panton-Valentine leukocidin-positive Staphylococcus aureus isolated in Okinawa, Japan].

    PubMed

    Miyagi, Ayano; Tokashiki, Yoshino T; Nakasone, Isamu; Kisanuki, Kyoko; Nago, Tamami T; Yamane, Nobuhisa

    2010-09-01

    We experienced hospital-acquired infection in March 2008 that three nurses became infected with Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA). Accordingly, we performed the retrospective study to determine the prevalence of PVL-positive S. aureus in Okinawa. A total of 731 clinical isolates, consisting of 600 MRSA and 131 methicillin-susceptible isolates in Okinawa, were included. Of the isolates, 16 were positive for PVL gene (lukS-PV-lukF-PV). All the PVL-positive isolates were MRSA, and the first appeared in March 2008. The isolates from the University Hospital were characterized as staphylococcal chromosomal cassette mec type IVa. Through the analysis of pulsed-field gel electrophoresis (PFGE), 16 PVL-positive MRSA isolates were divided in three groups. One isolate (the first group) from the other hospital was less similar (< 40% similarity) when compared with the remaining 15 isolates from the University Hospital. The second group consisted of two respective paired isolates from the same department wards, and those were very similar with each other, indicating possible patient-to-patient transmission. The 11 isolates were characterized as the third group with >80% similarity. The DiversiLab system (bioMérieux) based on repetitive-sequence-based PCR typing demonstrated that the isolates of the third group were similar and indistinguishable with the strains of USA300 clone. However, the first and second groups were not determinable which USA clone was the origin. With these, we could conclude that the PVL-positive MRSA close to USA300 clone first appeared in Okinawa in 2008 and is now becoming prevalent multi-focally. Also, person-to-person transmission is already likely in a hospital setting.

  19. Global Distribution of Panton-Valentine Leukocidin–positive Methicillin-resistant Staphylococcus aureus, 2006

    PubMed Central

    Bes, Michele; Meugnier, Helene; Lina, Gerard; Bozdogan, Bülent; Courvalin, Patrice; Reverdy, Marie-Elisabeth; Enright, Mark C.; Vandenesch, François; Etienne, Jerome

    2007-01-01

    We determined the agr type, multilocus sequence type, protein A gene type (spa typing), toxin gene profile, and antimicrobial drug resistance profile of 469 isolates of Panton-Valentine leukocidin–positive community-acquired methicillin-resistant Staphylococcus aureus isolates (PVL-positive CA-MRSA). The isolates had been collected from around the world from 1999 through 2005 by the French National Reference Center for Staphylococci. We found that some continent-specific clones described in 2003, such as clone ST8, have now spread all over the world. Likewise, some PVL-positive CA-MRSA have spread to several countries on various continents. New clones have emerged (e.g., ST377) on new genetic backgrounds. PVL-positive CA-MRSA that were usually susceptible to most antistaphylococcal antimicrobial agents have acquired new resistance determinants (e.g., to gentamicin) in certain countries. The major trait shared by all these clones is a short staphylococcal chromosomal cassette mec element of type IV or V. PMID:17553275

  20. msaABCR operon positively regulates biofilm development by repressing proteases and autolysis in Staphylococcus aureus.

    PubMed

    Sahukhal, Gyan S; Batte, Justin L; Elasri, Mohamed O

    2015-02-01

    Staphylococcus aureus is an important human pathogen that causes nosocomial and community-acquired infections. One of the most important aspects of staphylococcal infections is biofilm development within the host, which renders the bacterium resistant to the host's immune response and antimicrobial agents. Biofilm development is very complex and involves several regulators that ensure cell survival on surfaces within the extracellular polymeric matrix. Previously, we identified the msaABCR operon as an additional positive regulator of biofilm formation. In this study, we define the regulatory pathway by which msaABCR controls biofilm formation. We demonstrate that the msaABCR operon is a negative regulator of proteases. The control of protease production mediates the processing of the major autolysin, Atl, and thus regulates the rate of autolysis. In the absence of the msaABCR operon, Atl is processed by proteases at a high rate, leading to increased cell death and a defect in biofilm maturation. We conclude that the msaABCR operon plays a key role in maintaining the balance between autolysis and growth within the staphylococcal biofilm.

  1. A novel positive regulatory element for exfoliative toxin A gene expression in Staphylococcus aureus.

    PubMed

    Sakurai, Susumu; Suzuki, Hitoshi; Hata, Toshiaki; Yoshizawa, Yukio; Nakayama, Ritsuko; Machida, Katsuhiko; Masuda, Shogo; Tsukiyama, Takashi

    2004-04-01

    A 1.4 kb positive regulatory element (ETA(exp)) that controls staphylococcal exfoliative toxin A (sETA) transcription was cloned from Staphylococcus aureus. ETA(exp) is located upstream of the cloned 5.8 kb eta gene (etaJ1) obtained from the chomosomal DNA of S. aureus ZM, the standard ETA-producing strain. The cETA prepared from an Escherichia coli transformant into which the recombinant plasmid petaJ1 (5.8 kb eta/pUC9) had been introduced was expressed at high levels in the culture supernatant and the ammonium-sulfate-precipitated culture supernatant fraction as shown by immunoblotting and the single radial immunodiffusion test. However, cETA produced by the recombinant plasmid petaJ3 containing the 1.7 kb eta sequence (etaJ3) with a 1.45 kb ETA(exp)-deficient eta fragment (1.7 kb eta/pUC9) obtained from the 5.8 kb eta sequence by subcloning was not detected in either the culture supernatant or the ammonium-sulfate-precipitated culture supernatant fraction (167-fold concentrate of the culture supernatant) by immunoblotting or the single radial immunodiffusion test. A large amount of cETA was produced by the 1.7 kb eta sequence when it was linked to ETA(exp) amplified by PCR (1.7 kb eta-ETA(exp)/pUC9), regardless of the orientation of ETA(exp) insertion. Northern blot hybridization showed lower levels of the transcripts of the 1.7 kb eta sequence than of the 5.8 kb eta sequence. The rsETA prepared from an S. aureus transformant into which the recombinant plasmid 3.4 kb eta-ETA(exp)/pYT3 (pYT3-etaJ6) had been introduced was expressed at high levels in the culture supernatant fraction as shown by the latex agglutination test. However, the agglutination titre in the culture supernatant fraction of rsETA produced by the recombinant plasmid (1.7 kb eta/pYT3) containing the 1.7 kb eta sequence carrying the 1.4 kb ETA(exp)-deficient eta fragment (pYT3-etaJ3) was 2500-4000 times lower than that of pYT3-etaJ6.

  2. Staphylococcus aureus and sore nipples.

    PubMed Central

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

    1996-01-01

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

  3. Lack of increase in time to blood culture positivity in a patient with persistent methicillin-resistant Staphylococcus aureus bacteremia predicts failure of antimicrobial therapy.

    PubMed

    Liao, Chun-Hsing; Huang, Yu-Tsung; Chu, Fang-Yeh; Lin, Tsui-Hsien; Hsueh, Po-Ren

    2008-08-01

    Time to positivity is an available parameter in automated blood culture systems. We report a patient with persistent methicillin-resistant Staphylococcus aureus bacteremia who received various regimens for treatment of methicillin-resistant S. aureus, and demonstrate that monitoring of the time to positive blood culture might be helpful in the early recognition of treatment failure.

  4. Production of 2-Aminophenoxazin-3-one by Staphylococcus aureus Causes False-Positive Results in β-Galactosidase Assays

    PubMed Central

    Tse, Herman; Chan, Elaine; Lam, Ching-Wan; Leung, Ka-Fai; Chow, Pat; Lee, Kim-Chung; Sze, Kong-Hung; Cheung, Stanley K. K.; Tse, Man-Kit; Ho, Pak-Leung; Leung, Sze-Pui; Lau, Susanna K. P.; Woo, Patrick C. Y.

    2012-01-01

    Staphylococcus aureus can be distinguished from similar coagulase-positive staphylococci by its absence of β-galactosidase activity. This is commonly tested using o-nitrophenyl-β-d-galactopyranoside (ONPG) as the substrate. Unexpectedly, 111 and 58 of 123 isolates displayed apparent β-galactosidase activity in the ONPG assay and on the Vitek 2 system, respectively. Compositional analysis showed that the yellow coloration of the positive ONPG assay resulted from production of 2-aminophenoxazin-3-one. Alternative β-galactosidase substrates like X-Gal (5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside) should be used for testing staphylococci. PMID:22972831

  5. Hospital Dissemination of tst-1-Positive Clonal Complex 5 (CC5) Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Wang, Min; Zheng, Yi; Mediavilla, Jose. R.; Chen, Liang; Kreiswirth, Barry. N.; Song, Yajun; Yang, Ruifu; Du, Hong

    2017-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA), is one of the most prevalent clinical pathogens isolated from hospital settings, and has increasingly identified in community settings. In China, the SCCmecIII-ST239 strains are disseminated in different geographic regions, accounting for >75% of all MRSA isolates in some national studies. Here we characterized 150 non-duplicate MRSA isolates collected from February 2012 to May 2013 in a tertiary hospital in Suzhou, Eastern China, to explore the molecular epidemiology. All isolates were characterized by spa typing, SCCmec typing, and detection of genes encoding Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin (TSST-1). Representative genotypes were also subjected to multilocus sequence typing (MLST). Antibiotic susceptibility testing was performed using BD Phoenix™ Automated Microbiology System. Molecular typing identified 11 clonal complex (CC) and 28 spa types, with the CC5-spa t002 (29.3%) and CC239-spa t037 (14.7%) being the most prevalent. SCCmec types II, III, IV, and V were identified in 33.3, 21.3, 23.3, and 21.3% of all isolates, respectively. PVL genes (lukF/S-PV) were detected in 11.3% of all isolates and from 6 CCs (5, 8, 59, 88, 239, and 398). The TSST-1 gene (tst) was detected in 18.0% of the all isolates, predominantly in CC5 (96.3%). All the tst-1-positve CC5 isolates were spa t002. Eighteen patients died within 30 days of hospitalization, and the in-hospital 30-day mortality was 12.0%. Multivariable analysis showed that 60 years old (odds ratio [OR] = 7.2, P = 0.026), cancer diagnosis (OR = 9.6, P = 0.022), and MRSA isolate carriage of tst-1 (OR = 62.5, P < 0.001) were independent factors associated with 30-day mortality. Our study revealed unique MRSA dissemination patterns in our hospital in comparison to those of other regions in China. The finding that tst-1-positive CC5 strains were associated with higher mortality highlights the need for strict infection control measures in

  6. 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

  7. Effect of stress on biofilm formation by icaA positive and negative strains of methicillin resistant Staphylococcus aureus.

    PubMed

    Mirani, Zulfiqar Ali; Khan, Muhammad Naseem; Aziz, Mubashir; Asadullah; Naz, Shagufta; Khan, Seema Ismat

    2012-01-01

    To determine the effect of physical and chemical stress factors e.g. antibiotics, NaCl, glucose, heat shock, cold shock and sonic waves on biofilm formation by icaA positive and negative strains of Methicillin resistant Staphylococcus (S.) aureus. Experimental study. Microbiological Analytical Centre, Pakistan Council of Scientific and Industrial Research (PCSIR) Laboratories Complex, Karachi, from January to December 2010. One strain of Staphylococcus aureus labelled as FA was isolated from a food sample and the other strain labelled as CL was a clinical strain. Biofilm assays were performed in brain-heart infusion (BHI) medium and in BHI supplemented with 7% NaCl, 5% glucose, or sub-inhibitory concentrations of Vancomycin, Oxacillin, Ampicillin, Tetracycline, Erythromycin, Rifampicin and Ciprofloxacin. Polymerase chain reaction (PCR) was used for screening of the icaA and mecA genes. The FA and CL were identified as MRSA carrying mecA gene. The strain FA showed biofilm formation without any treatment and was found to carry icaA gene contrary to CL, that does not contain this gene therefore, is unable to produce biofilm under normal conditions without any stress. The use of sub-lethal doses of cell wall active antibiotics, exposure to 7% NaCl, sonication, and heat shock were found to augment biofilm quantity in FA, an icaA positive strain and induce biofilm mode of growth in CL, an icaA negative strain. Anti-protein synthesis antibiotics did not show any effect on biofilm formation process in icaA positive or negative strains. There is a role of anti-cell wall factors i.e. sonication, heat shock, NaCl and antibiotics in the induction of biofilm mode of growth in MRSA and Methicillin sensitive S. aureus. The factors which partially damage bacterial cell wall, equally, induce biofilm formation in icaA positive or negative S. aureus.

  8. SarA positively controls bap-dependent biofilm formation in Staphylococcus aureus.

    PubMed

    Trotonda, María Pilar; Manna, Adhar C; Cheung, Ambrose L; Lasa, Iñigo; Penadés, José R

    2005-08-01

    The biofilm-associated protein Bap is a staphylococcal surface protein involved in biofilm formation. We investigated the influence of the global regulatory locus sarA on bap expression and Bap-dependent biofilm formation in three unrelated Staphylococcus aureus strains. The results showed that Bap-dependent biofilm formation was diminished in the sarA mutants by an agr-independent mechanism. Complementation studies using a sarA clone confirmed that the defect in biofilm formation was due to the sarA mutation. As expected, the diminished capacity to form biofilms in the sarA mutants correlated with the decreased presence of Bap in the bacterial surface. Using transcriptional fusion and Northern analysis data, we demonstrated that the sarA gene product acts as an activator of bap expression. Finally, the bap promoter was characterized and the transcriptional start point was mapped by the rapid amplification of cDNA ends technique. As expected, we showed that purified SarA protein binds specifically to the bap promoter, as determined by gel shift and DNase I footprinting assays. Based on the previous studies of others as well as our work demonstrating the role for SarA in icaADBC and bap expression, we propose that SarA is an essential regulator controlling biofilm formation in S. aureus.

  9. SarA Positively Controls Bap-Dependent Biofilm Formation in Staphylococcus aureus

    PubMed Central

    Trotonda, María Pilar; Manna, Adhar C.; Cheung, Ambrose L.; Lasa, Iñigo; Penadés, José R.

    2005-01-01

    The biofilm-associated protein Bap is a staphylococcal surface protein involved in biofilm formation. We investigated the influence of the global regulatory locus sarA on bap expression and Bap-dependent biofilm formation in three unrelated Staphylococcus aureus strains. The results showed that Bap-dependent biofilm formation was diminished in the sarA mutants by an agr-independent mechanism. Complementation studies using a sarA clone confirmed that the defect in biofilm formation was due to the sarA mutation. As expected, the diminished capacity to form biofilms in the sarA mutants correlated with the decreased presence of Bap in the bacterial surface. Using transcriptional fusion and Northern analysis data, we demonstrated that the sarA gene product acts as an activator of bap expression. Finally, the bap promoter was characterized and the transcriptional start point was mapped by the rapid amplification of cDNA ends technique. As expected, we showed that purified SarA protein binds specifically to the bap promoter, as determined by gel shift and DNase I footprinting assays. Based on the previous studies of others as well as our work demonstrating the role for SarA in icaADBC and bap expression (J. Valle, A. Toledo-Arana, C. Berasain, J. M. Ghigo, B. Amorena, J. R. Penades, and I. Lasa, Mol. Microbiol. 48:1075-1087), we propose that SarA is an essential regulator controlling biofilm formation in S. aureus. PMID:16077127

  10. First description of PVL-positive methicillin-resistant Staphylococcus aureus (MRSA) in wild boar meat.

    PubMed

    Kraushaar, Britta; Fetsch, Alexandra

    2014-09-01

    Staphylococcus aureus is an important food-borne pathogen due to the ability of enterotoxigenic strains to produce staphylococcal enterotoxins (SEs) in food. Methicillin-resistant S. aureus (MRSA) is also an important pathogen for humans, causing severe and hard to treat diseases in hospitals and in the community due to its multiresistance against antimicrobials. In particular, strains harbouring genes encoding for the Panton-Valentine leukocidin (PVL) toxin are of concern from a public health perspective as they are usually capable of causing severe skin and soft tissue infections (sSSTIs) and occasionally necrotizing pneumonia which is associated with high mortality. This is the first report on the detection of MRSA with genes encoding for PVL in wild boar meat. Among the 28 MRSA isolated from wild boar meat in the course of a national monitoring programme in Germany, seven harboured PVL-encoding genes. Six of the isolates were identical according to the results of spa-, MLST-, microarray- and PFGE-typing. They could be assigned to the epidemic MRSA clone USA300. Epidemiological investigations revealed that people handling the food were the most likely common source of contamination with these MRSA. These findings call again for suitable hygienic measures at all processing steps of the food production chain. The results of the study underline that monitoring along the food chain is essential to closely characterise the total burden of MRSA for public health.

  11. [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.

  12. 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

  13. Staphylococcus aureus: a community pathogen.

    PubMed

    Miller, Loren G; Kaplan, Sheldon L

    2009-03-01

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

  14. A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus.

    PubMed

    Shangguan, Jingfang; Li, Yuhong; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Zou, Zhen; Shi, Hui

    2015-07-07

    Staphylococcus aureus (S. aureus) is an important human pathogen that causes several diseases ranging from superficial skin infections to life-threatening diseases. Here, a method combining positive dielectrophoresis (pDEP) driven on-line enrichment and aptamer-fluorescent silica nanoparticle label has been developed for the rapid and sensitive detection of S. aureus in microfluidic channels. An aptamer, having high affinity to S. aureus, is used as the molecular recognition tool and immobilized onto chloropropyl functionalized fluorescent silica nanoparticles through a click chemistry approach to obtain S. aureus aptamer-nanoparticle bioconjugates (Apt(S.aureus)/FNPs). The pDEP driven on-line enrichment technology was used for accumulating the Apt(S.aureus)/FNP labeled S. aureus. After incubating with S. aureus, the mixture of Apt(S.aureus)/FNP labeled S. aureus and Apt(S.aureus)/FNPs was directly introduced into the pDEP-based microfluidic system. By applying an AC voltage in a pDEP frequency region, the Apt(S.aureus)/FNP labelled S. aureus moved to the electrodes and accumulated in the electrode gap, while the free Apt(S.aureus)/FNPs flowed away. The signal that came from the Apt(S.aureus)/FNP labelled S. aureus in the focused detection areas was then detected. Profiting from the specificity of aptamer, signal amplification of FNP label and pDEP on-line enrichment, this assay can detect as low as 93 and 270 cfu mL(-1)S. aureus in deionized water and spiked water samples, respectively, with higher sensitivities than our previously reported Apt(S.aureus)/FNP based flow cytometry. Moreover, without the need for separation and washing steps usually required for FNP label involved bioassays, the total assay time including sample pretreatment was within 2 h.

  15. Prevalence and Characterization of Oxacillin Susceptible mecA-Positive Clinical Isolates of Staphylococcus aureus Causing Bovine Mastitis in India

    PubMed Central

    Mistry, Hiral; Sharma, Paresh; Mahato, Sudipta; Saravanan, R.; Kumar, P. Anand; Bhandari, Vasundhra

    2016-01-01

    Bovine mastitis caused by multidrug resistant Staphylococcus aureus is a huge problem reported worldwide, resulting in prolonged antibiotic treatment and death of livestock. The current study is focused on surveillance of antibiotic susceptibility along with genotypic and phenotypic characterization of the pathogenic S. aureus strains causing mastitis in India. One hundred and sixty seven milk samples were collected from mastitis-affected cows from different farms in India resulting in thirty nine isolated S. aureus strains. Antibiotic sensitivity profiling revealed the majority of the strains (n = 24) to be multidrug resistant and eleven strains showed reduced susceptibility to vancomycin (MICs = 2μg/ml). All strains were oxacillin sensitive, but 19 strains were positive for the mecA gene, which revealed the occurrence of oxacillin susceptible mecA positive strains (OS-MRSA) for the first time from India. Additionally, 32 strains were positive for the pvl gene, a virulence determinant; of these 17 were also OS-MRSA strains. Molecular characterization based on multilocus sequence typing (MLST), spa typing, agr typing and SCCmec classification revealed strains belonging to different groups. Moreover, strains showed spa types (t2526, t9602) and MLST sequence types, ST-72, ST-88 and ST-239 which have been earlier reported in human infections. The prevalence of OS-MRSA strains indicates the importance of including both the genetic and phenotypic tests in characterizing S. aureus strains. Increased genotypic variability with strain related to human infections and pvl positive isolates indicates a worrisome situation with the possibility of bilateral transfer. PMID:27603123

  16. Rapid differentiation of Staphylococcus aureus, Staphylococcus epidermidis and other coagulase-negative staphylococci and meticillin susceptibility testing directly from growth-positive blood cultures by multiplex real-time PCR.

    PubMed

    Jukes, Leanne; Mikhail, Jane; Bome-Mannathoko, Naledi; Hadfield, Stephen J; Harris, Llinos G; El-Bouri, Khalid; Davies, Angharad P; Mack, Dietrich

    2010-12-01

    This study evaluated a multiplex real-time PCR method specific for the mecA, femA-SA and femA-SE genes for rapid identification of Staphylococcus aureus, Staphylococcus epidermidis and non-S. epidermidis coagulase-negative staphylococci (CoNS), and meticillin susceptibility testing directly in positive blood cultures that grew Gram-positive cocci in clusters. A total of 100 positive blood cultures produced: 39 S. aureus [12 meticillin-resistant S. aureus (MRSA), 31% of all the S. aureus]; 30 S. epidermidis (56.6% of the CoNS), 8 Staphylococcus capitis (15.1%), 3 Staphylococcus saprophyticus (5.7%), 4 Staphylococcus hominis (7.5%), 3 Staphylococcus haemolyticus (5.7%), 2 Staphylococcus warneri (3.8%), 1 Staphylococcus cohnii (1.9%) and 2 unidentified Staphylococcus spp. (3.8%); and 1 Micrococcus luteus in pure culture. Two blood cultures had no growth on subculture and five blood cultures grew mixed CoNS. For the 95 blood cultures with pure growth or no growth on subculture, there was very good agreement between real-time PCR and the BD Phoenix identification system for staphylococcal species categorization in S. aureus, S. epidermidis and non-S. epidermidis CoNS and meticillin-resistance determination (Cohen's unweighted kappa coefficient κ=0.882). All MRSA and meticillin-susceptible S. aureus were correctly identified by mecA amplification. PCR amplification of mecA was more sensitive for direct detection of meticillin-resistant CoNS in positive blood cultures than testing with the BD Phoenix system. There were no major errors when identifying staphylococcal isolates and their meticillin susceptibility within 2.5 h. Further studies are needed to evaluate the clinical benefit of using such a rapid test on the consumption of glycopeptide antibiotics and the alteration of empiric therapy in the situation of positive blood cultures growing staphylococci, and the respective clinical outcomes.

  17. Increased Age-Dependent Risk of Death Associated With lukF-PV-Positive Staphylococcus aureus Bacteremia

    PubMed Central

    Knudsen, Trine A.; Skov, Robert; Petersen, Andreas; Larsen, Anders R.

    2016-01-01

    Background. Panton-Valentine leucocidin is a Staphylococcus aureus virulence factor encoded by lukF-PV and lukS-PV that is infrequent in S aureus bacteremia (SAB), and, therefore, little is known about risk factors and outcome of lukF-PV/lukS-PV-positive SAB. Methods. This report is a register-based nationwide observational cohort study. lukF-PV was detected by polymerase chain reaction. Factors associated with the presence of lukF-PV were assessed by logistic regression analysis. Adjusted 30-day hazard ratios of mortality associated with lukF-PV status were computed by Cox proportional hazards regression analysis. Results. Of 9490 SAB cases, 129 were lukF-PV-positive (1.4%), representing 14 different clonal complexes. lukF-PV was associated with younger age, absence of comorbidity, and methicillin-resistant S aureus. In unadjusted analysis, mortality associated with lukF-PV-positive SAB was comparable to SAB. However, lukF-PV-positive SAB nonsurvivors were significantly older and had more comorbidity. Consequently, by adjusted analysis, the risk of 30-day mortality was increased by 70% for lukF-PV-positive SAB compared with SAB (hazard ratio, 1.70; 95% confidence interval, 1.20–2.42; P = .003). Conclusions. lukF-PV-positive SAB is rare in Denmark but associated with a significantly increased risk of mortality. Although the risk of lukF-PV-positive SAB was highest in the younger age groups, >80% of deaths associated with lukF-PV-positive SAB occurred in individuals older than 55 years. PMID:27957504

  18. Methicillin-resistant Staphylococcus aureus (MRSA)

    MedlinePlus

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

  19. 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.

  20. C55 bacteriocin produced by ETB-plasmid positive Staphylococcus aureus strains is a key factor for competition with S. aureus strains.

    PubMed

    Kawada-Matsuo, Miki; Shammi, Fariha; Oogai, Yuichi; Nakamura, Norifumi; Sugai, Motoyuki; Komatsuzawa, Hitoshi

    2016-03-01

    Exfoliative toxin (ET) produced by Staphylococcus aureus is closely associated with the onset of bullous impetigo. To date, three ETs (ETA, ETB and ETD) have been identified. The gene encoding ETB is located in a plasmid designated pETB. Bacteriocin synthesis genes are also located in this plasmid and pETB-positive strains reportedly produce the C55 bacteriocin. In this study, the antibacterial activity against S. aureus strains of the bacteriocin produced by the pETB-positive strain TY4 was investigated. This bacteriocin demonstrated antibacterial activity against all pETB-negative but not pETB-positive strains, including TY4. Additionally, a TY4- strain from which the pETB plasmid had been deleted exhibited susceptibility to the bacteriocin. Further experiments revealed that two immunity factors (orf 46-47 and orf 48) downstream of the bacteriocin synthesis genes in the pETB plasmid are associated with immunity against the bacteriocin produced by TY4. The TY4- with orf46-47 strain exhibited complete resistance to bacteriocin, whereas the TY4- with orf48 strain exhibited partial resistance. Whether bacteriocin affects the proportion of each strain when co-cultured with S. aureus strains was also investigated. When TY4 or TY4- was co-cultured with 209P strain, which is susceptible to the bacteriocin, the proportion of 209P co-cultured with TY4 was significantly less than when 209P was co-cultured with TY4-, whereas the proportion of TY4- with orf46-48 co-cultured with TY4 was greater than with TY4-. These results suggest that the C55 bacteriocin produced by pETB-positive strains affects the proportion of each strain when pETB-positive and -negative strains co-exist.

  1. 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.

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

    PubMed

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

    2009-01-01

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

  3. Differential mode of antimicrobial actions of arginine-rich and lysine-rich histones against Gram-positive Staphylococcus aureus.

    PubMed

    Morita, Shuu; Tagai, Chihiro; Shiraishi, Takayuki; Miyaji, Kazuyuki; Iwamuro, Shawichi

    2013-10-01

    We previously reported the activities and modes of action of arginine (Arg)-rich histones H3 and H4 against Gram-negative bacteria. In the present study, we investigated the properties of the Arg-rich histones against Gram-positive bacteria in comparison with those of lysine (Lys)-rich histone H2B. In a standard microdilution assay, calf thymus histones H2B, H3, and H4 showed growth inhibitory activity against Staphylococcus aureus with minimum effective concentration values of 4.0, 4.0, and 5.6 μM, respectively. Laser confocal microscopic analyses revealed that both the Arg-rich and Lys-rich histones associated with the surface of S. aureus. However, while the morphology of S. aureus treated with histone H2B appeared intact, those treated with the histones H3 and H4 closely resembled each other, and the cells were blurred. Electrophoretic mobility shift assay results revealed these histones have binding affinity to lipoteichoic acid (LTA), one of major cell surface components of Gram-positive bacteria. Scanning electron microscopic analyses demonstrated that while histone H2B elicited no obvious changes in cell morphology, histones H3 and H4 disrupted the cell membrane structure with bleb formation in a manner similar to general antimicrobial peptides. Consequently, our results suggest that bacterial cell surface LTA initially attracts both the Arg- and Lys-rich histones, but the modes of antimicrobial action of these histones are different; the former involves cell membrane disruption and the latter involves the cell integrity disruption.

  4. Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina.

    PubMed

    Fernandez, Silvina; Murzicato, Sofía; Sandoval, Orlando; Fernández-Canigia, Liliana; Mollerach, Marta

    2015-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient.

  5. Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay.

    PubMed

    Becker, Karsten; Denis, Olivier; Roisin, Sandrine; Mellmann, Alexander; Idelevich, Evgeny A; Knaack, Dennis; van Alen, Sarah; Kriegeskorte, André; Köck, Robin; Schaumburg, Frieder; Peters, Georg; Ballhausen, Britta

    2016-01-01

    An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categorized.

  6. Metabolome analysis of gram-positive bacteria such as Staphylococcus aureus by GC-MS and LC-MS.

    PubMed

    Liebeke, Manuel; Dörries, Kirsten; Meyer, Hanna; Lalk, Michael

    2012-01-01

    The field of metabolomics has become increasingly important in the context of functional genomics. Together with other "omics" data, the investigation of the metabolome is an essential part of systems biology. Beside the analysis of human and animal biofluids, the investigation of the microbial physiology by methods of metabolomics has gained increased attention. For example, the analysis of metabolic processes during growth or virulence factor expression is crucially important to understand pathogenesis of bacteria. Common bioanalytical techniques for metabolome analysis include liquid and gas chromatographic methods coupled to mass spectrometry (LC-MS and GC-MS) and spectroscopic approaches such as NMR. In order to achieve metabolome data representing the physiological status of a microorganism, well-verified protocols for sampling and analysis are necessary. This chapter presents a detailed protocol for metabolome analysis of the Gram-positive bacterium Staphylococcus aureus. A detailed manual for cell sampling and metabolite extraction is given, followed by the description of the analytical procedures GC-MS and LC-MS. The advantages and limitations of each experimental setup are discussed. Here, a guideline specified for S. aureus metabolomics and information for important protocol steps are presented, to avoid common pitfalls in microbial metabolome analysis.

  7. [Vancomycin-resistant Staphylococcus aureus].

    PubMed

    Rodríguez, Carlos Andrés; Vesga, Omar

    2005-12-01

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

  8. Characteristics of cefazolin inoculum effect-positive methicillin-susceptible staphylococcus aureus infection in a multicentre bacteraemia cohort.

    PubMed

    Song, K-H; Jung, S-I; Lee, S; Park, S; Kiem, S M; Lee, S H; Kwak, Y G; Kim, Y K; Jang, H-C; Kim, Y-S; Kim, H-I; Kim, C J; Park, K-H; Kim, N J; Oh, M-D; Kim, H B

    2017-02-01

    Cefazolin treatment failure has been observed in high-inoculum infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) with a cefazolin inoculum effect (CIE). However, data on the characteristics and risk factors for the acquisition of CIE-positive MSSA infection are scarce. CIE positivity was measured as an MIC ≥ 16 μg/ml with a high inoculum (∼5 × 10(7) CFU/ml). The blaZ gene type was assessed through sequence analysis. The clinical characteristics and risk factors for the acquisition of CIE-positive MSSA infection were assessed. The association between the antimicrobial susceptibility profile and CIE positivity was evaluated. A total of 303 MSSA bacteraemia cases and their corresponding isolates were collected from ten hospitals: 61 (20.1 %) isolates showed a positive CIE; 254 (83.8 %) were positive for the blaZ gene. No significant association was found between CIE positivity and the site of infection. Metastatic cancer (aOR 2.86, 95 % CI, 1.10-7.48) and recent (≤1 month) close contact with a chronically ill patient (aOR 4.69, 95 % CI, 1.76-12.50) were identified as significant risk factors for CIE-positive MSSA infection through multivariate analyses. Resistances to clindamycin (OR 3.55, 95 % CI, 1.62-7.80) and erythromycin (OR 5.00, 95 % CI, 2.50-9.99) were associated with CIE positivity, presenting high specificity (92.9 %) and a negative predictive value (82.3 %). CIE-positive MSSA constituted approximately one-fifth of MSSA bacteraemia cases. Although CIE positivity was not clinically discernible, CIE positivity was associated with clindamycin or erythromycin susceptibility. Therefore, our findings suggest that cefazolin can be used in the treatment of high-inoculum MSSA infection if the isolates are susceptible to clindamycin or erythromycin.

  9. 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.

  10. 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.

  11. Antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin-positive meticillin-resistant Staphylococcus aureus: An international survey.

    PubMed

    Macedo-Viñas, Marina; Conly, John; Francois, Patrice; Aschbacher, Richard; Blanc, Dominique S; Coombs, Geoffrey; Daikos, George; Dhawan, Benu; Empel, Joanna; Etienne, Jerome; Figueiredo, Agnes Marie Sá; George Golding Cnisp; Han, Lizhong; Kim, Hong Bin; Köck, Robin; Larsen, Anders; Layer, Franziska; Lo, Janice; Maeda, Tadashi; Mulvey, Michael; Pantosti, Annalisa; Saga, Tomoo; Schrenzel, Jacques; Simor, Andrew; Skov, Robert; Van Rijen, Miranda; Wang, Hui; Zakaria, Zunita; Harbarth, Stephan

    2014-03-01

    The antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin (PVL)-positive meticillin-resistant Staphylococcus aureus (MRSA) isolates reported from 17 countries in the Americas, Europe and, Australia-Asia were analysed. Among a total of 3236 non-duplicate isolates, the lowest susceptibility was observed to erythromycin in all regions. Susceptibility to ciprofloxacin showed large variation (25%, 75% and 84% in the Americas, Europe and Australia-Asia, respectively). Two vancomycin-intermediate PVL-positive MRSA isolates were reported, one from Hong Kong and the other from The Netherlands. Resistance to trimethoprim/sulfamethoxazole and linezolid was <1%. Among 1798 MRSA isolates from 13 countries that were tested for the requested 10 non-β-lactam antibiotics, 49.4% were multisusceptible. However, multiresistant isolates (resistant to at least three classes of non-β-lactam antibiotics) were reported from all regions. Sequence type 30 (ST30) was reported worldwide, whereas ST80 and ST93 were exclusive to Europe and Australia, respectively. USA300 and related clones (ST8) are progressively replacing the ST80 clone in several European countries. Eight major clusters were discriminated by multilocus variable-number tandem repeat assay (MLVA), showing a certain geographic specificity. PVL-positive MRSA isolates frequently remain multisusceptible to non-β-lactam agents, but multiresistance is already prevalent in all regions. Surveillance of MRSA susceptibility patterns should be monitored to provide clinicians with the most current information regarding changes in resistance patterns.

  12. Antibacterial therapy of aspiration pneumonia in patients with methicillin-resistant Staphylococcus aureus-positive sputum: identification of risk factors.

    PubMed

    Shinoda, Y; Matsuoka, T; Mori, T; Yoshida, S; Ohashi, K; Yoshimura, T; Sugiyama, T

    2016-02-01

    Inappropriate antimicrobial treatment could adversely affect the recovery of patients with aspiration pneumonia. We attempted to identify inappropriate antibacterial treatment and to determine the standard use of anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs in aspiration pneumonia patients with MRSA-positive in sputum. Aspiration pneumonia patients with MRSA-positive sputum treated between January 2013 and May 2013 were included in this study to determine the risk factors for death during hospitalization. The relationship between anti-MRSA medicine use and death during hospitalization was also investigated. More than 10⁷ MRSA colony-forming units in sputum culture, creatinine clearance of less than 30 mL/min, and quinolone use were found to be risk factors for death during hospitalization. The death rate during hospitalization was significantly lower in cases a Geckler classification of 4 or 5 when anti-MRSA treatment was initiated soon after the culture was obtained. Therefore, we concluded that the use of quinolones as antibacterial treatment in aspiration pneumonia patients with MRSA-positive sputum should be avoided and that anti-MRSA treatment should be started in cases with good quality sputum cultures.

  13. Novel Structure of Enterococcus faecium-Originated ermB-Positive Tn1546-Like Element in Staphylococcus aureus.

    PubMed

    Wan, Tsai-Wen; Hung, Wei-Chun; Tsai, Jui-Chang; Lin, Yu-Tzu; Lee, Hao; Hsueh, Po-Ren; Lee, Tai-Fen; Teng, Lee-Jene

    2016-10-01

    We determined the resistance determinants in 274 erythromycin-resistant methicillin-susceptible Staphylococcus aureus (MSSA) isolates during a 13-year period, 2000 to 2012. The resistance phenotypes, inducible macrolide-lincosamide-streptogramin (iMLS), constitutive MLS (cMLS), and macrolide-streptogramin (MS) resistance phenotypes, were examined by a double-disk diffusion D test. The ermB gene was more frequent (35%; 97/274) than ermC (27%; 75/274) or ermA (21%; 58/274). All 97 ermB-positive isolates harbored Tn551 and IS1216V The majority (89/97) of ermB-positive isolates displayed the cMLS phenotype and carried mobile element structure (MES)-like structures, which has been previously reported in sequence type 59 (ST59) methicillin-resistant S. aureus (MRSA). The remaining 8 ermB-carrying isolates, belonging to ST7 (n = 4), ST5 (n = 3), and ST59 (n = 1), were sasK intact and did not carry MES-like structures. Unlike a MES-like structure that was located on the chromosome, the ermB elements on sasK-intact isolates were located on plasmids by S1 nuclease pulsed-field gel electrophoresis (PFGE) analysis and conjugation tests. Sequence data for the ermB-containing region (14,566 bp) from ST59 NTUH_3874 revealed that the best match was a Tn1546-like element in plasmid pMCCL2 DNA (GenBank accession number AP009486) of Macrococcus caseolyticus Tn1546 is recognized as an enterococcal transposon and was known from the vancomycin resistance gene cluster in vancomycin-resistant Enterococcus (VRE). So far, acquisitions of Tn1546 in S. aureus have occurred in clonal complex 5 (CC5) MRSA, but not in MSSA. This is the first report that MSSA harbors an Enterococcus faecium-originated ermB-positive Tn1546-like element located on a plasmid. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. Prevalence of community-associated meticillin-resistant Staphylococcus aureus and Panton-Valentine leucocidin-positive S. aureus in general practice patients with skin and soft tissue infections in the northern and southern regions of The Netherlands.

    PubMed

    Mithoe, D; Rijnders, M I A; Roede, B M; Stobberingh, E; Möller, A V M

    2012-03-01

    The purpose of this investigation was to determine the prevalence of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) and Panton-Valentine leucocidin (PVL)-positive S. aureus in general practice (GP) patients with skin and soft tissue infections (SSTI) in the northern (Groningen and Drenthe) and southern (Limburg) regions of The Netherlands. Secondary objectives were to assess the possible risk factors for patients with SSTI caused by S. aureus and PVL-positive S. aureus using a questionnaire-based survey. From 2007 to 2008, wound and nose cultures were obtained from patients with SSTI in general practice. These swabs were analysed for the presence of S. aureus and the antibiotic susceptibility was determined. The presence of the PVL toxin gene was determined by polymerase chain reaction (PCR) and the genetic background with the use of spa typing. A survey was performed to detect risk factors for S. aureus infection and for the presence of PVL toxin.S. aureus was isolated from 219 out of 314 (70%) patients with SSTI, of which two (0.9%) patients were MRSA-positive. In 25 (11%) patients, the PVL toxin gene was found. A higher prevalence of PVL-positive S. aureus of patients with SSTI was found in the northern region compared to the south (p < 0.05). Regional differences were found in the spa types of PVL-positive S. aureus isolates, and for PVL-negative S. aureus isolates, the genetic background was similar in both regions. The prevalence of CA-MRSA in GP patients with SSTI in The Netherlands is low. Regional differences were found in the prevalence of PVL-positive S. aureus isolates from GP patients with SSTI. Household contacts having similar symptoms were found to be a risk factor for SSTI with S. aureus.

  15. 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).

  16. Detection of mecC-positive Staphylococcus aureus (CC130-MRSA-XI) in diseased European hedgehogs (Erinaceus europaeus) in Sweden.

    PubMed

    Monecke, Stefan; Gavier-Widen, Dolores; Mattsson, Roland; Rangstrup-Christensen, Lena; Lazaris, Alexandros; Coleman, David C; Shore, Anna C; Ehricht, Ralf

    2013-01-01

    Recently, a novel mec gene conferring beta-lactam resistance in Staphylococcus aureus has been discovered. This gene, mecC, is situated on a SCCmec XI element that has to date been identified in clonal complexes 49, 130, 425, 599 and 1943. Some of the currently known isolates have been identified from animals. This, and observations of mecA alleles that do not confer beta-lactam resistance, indicate that mec genes might have a reservoir in Staphylococcus species from animals. Thus it is important also to screen wildlife isolates for mec genes. Here, we describe mecC-positive Staphylococcus aureus (ST130-MRSA-XI) and the lesions related to the infection in two diseased free-ranging European hedgehogs (Erinaceus europaeus). One was found dead in 2003 in central Sweden, and suffered from S. aureus septicaemia. The other one, found on the island of Gotland in the Baltic Sea in 2011, showed a severe dermatitis and was euthanised. ST130-MRSA-XI isolates were isolated from lesions from both hedgehogs and were essentially identical to previously described isolates from humans. Both isolates carried the complete SCCmec XI element. They lacked the lukF-PV/lukS-PV and lukM/lukF-P83 genes, but harboured a gene for an exfoliative toxin homologue previously described from Staphylococcus hyicus, Staphylococcus pseudintermedius and other S. aureus of the CC130 lineage. To the best of our knowledge, these are the first reported cases of CC130-MRSA-XI in hedgehogs. Given that one of the samples was taken as early as 2003, this was the earliest detection of this strain and of mecC in Sweden. This and several other recent observations suggest that CC130 might be a zoonotic lineage of S. aureus and that SCCmec XI/mecC may have originated from animal pathogens.

  17. Detection of mecC-Positive Staphylococcus aureus (CC130-MRSA-XI) in Diseased European Hedgehogs (Erinaceus europaeus) in Sweden

    PubMed Central

    Monecke, Stefan; Gavier-Widen, Dolores; Mattsson, Roland; Rangstrup-Christensen, Lena; Lazaris, Alexandros; Coleman, David C.; Shore, Anna C.; Ehricht, Ralf

    2013-01-01

    Recently, a novel mec gene conferring beta-lactam resistance in Staphylococcus aureus has been discovered. This gene, mecC, is situated on a SCCmec XI element that has to date been identified in clonal complexes 49, 130, 425, 599 and 1943. Some of the currently known isolates have been identified from animals. This, and observations of mecA alleles that do not confer beta-lactam resistance, indicate that mec genes might have a reservoir in Staphylococcus species from animals. Thus it is important also to screen wildlife isolates for mec genes. Here, we describe mecC-positive Staphylococcus aureus (ST130-MRSA-XI) and the lesions related to the infection in two diseased free-ranging European hedgehogs (Erinaceus europaeus). One was found dead in 2003 in central Sweden, and suffered from S. aureus septicaemia. The other one, found on the island of Gotland in the Baltic Sea in 2011, showed a severe dermatitis and was euthanised. ST130-MRSA-XI isolates were isolated from lesions from both hedgehogs and were essentially identical to previously described isolates from humans. Both isolates carried the complete SCCmec XI element. They lacked the lukF-PV/lukS-PV and lukM/lukF-P83 genes, but harboured a gene for an exfoliative toxin homologue previously described from Staphylococcus hyicus, Staphylococcus pseudintermedius and other S. aureus of the CC130 lineage. To the best of our knowledge, these are the first reported cases of CC130-MRSA-XI in hedgehogs. Given that one of the samples was taken as early as 2003, this was the earliest detection of this strain and of mecC in Sweden. This and several other recent observations suggest that CC130 might be a zoonotic lineage of S. aureus and that SCCmec XI/mecC may have originated from animal pathogens. PMID:23776626

  18. An international, prospective, multicenter evaluation of the combination of AdvanDx Staphylococcus QuickFISH BC with mecA XpressFISH for detection of methicillin-resistant Staphylococcus aureus isolates from positive blood cultures.

    PubMed

    Salimnia, H; Fairfax, M R; Lephart, P; Morgan, M; Gilbreath, J J; Butler-Wu, S M; Templeton, K E; Hamilton, F J; Wu, F; Buckner, R; Fuller, D; Davis, T E; Abdelhamed, A M; Jacobs, M R; Miller, A; Pfrommer, B; Carroll, K C

    2014-11-01

    Sepsis caused by Staphylococcus aureus is a major health problem worldwide. Better outcomes are achieved when rapid diagnosis and determination of methicillin susceptibility enable early optimization of antimicrobial therapy. Eight large clinical laboratories, seven from the United States and one from Scotland, evaluated the combination of the Staphylococcus QuickFISH BC and the new mecA XpressFISH assay (both AdvanDx, Woburn, MA, USA) for the detection of methicillin-resistant S. aureus in positive blood cultures. Blood cultures flagged as positive by automated blood culture instruments and demonstrating only Gram-positive cocci in clusters on Gram stain were tested by QuickFISH, a 20-min assay. If only S. aureus was detected, mecA XpressFISH testing followed. The recovered S. aureus isolates were tested by cefoxitin disk diffusion as the reference method. The QuickFISH assay results were concordant with the routine phenotypic testing methods of the testing laboratories in 1,211/1,221 (99.1%) samples and detected 488/491 S. aureus organisms (sensitivity, 99.4%; specificity, 99.6%). Approximately 60% of the samples (730) contained coagulase-negative staphylococci or nonstaphylococci as assessed by the QuickFISH assay and were not tested further. The 458 compliant samples positive exclusively for S. aureus by the QuickFISH assay were tested by the mecA XpressFISH assay, which detected 209 of 211 methicillin-resistant S. aureus organisms (sensitivity, 99.1%; specificity, 99.6%). The mecA XpressFISH assay also showed high reproducibility, with 534/540 tests performed by 6 operators over 5 days achieving reproducible results (98.9% agreement). The combination of the Staphylococcus QuickFISH BC and mecA XpressFISH assays is sensitive, specific, and reproducible for the detection of methicillin-resistant S. aureus and yields complete results in 2 h after the blood culture turns positive.

  19. Triclosan Promotes Staphylococcus aureus Nasal Colonization

    PubMed Central

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

    2014-01-01

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

  20. [Infections caused by multi-resistant Gram-positive bacteria (Staphylococcus aureus and Enterococcus spp.)].

    PubMed

    Cantón, Rafael; Ruiz-Garbajosa, Patricia

    2013-10-01

    Methicillin -resistant Staphylocccus aureus (MRSA) and multirresistant entorococci are still problematic in nosocomial infections and new challenges have emerged for their containment. MRSA has increased the multiresistant profile; it has been described vancomycin and linezolid resistant isolates and isolates with decreased daptomycin susceptibility. Moreover, new clones (ST398) have emerged, initially associated with piggeries, and new mec variants (mecC) with livestock origin that escape to the detection with current molecular methods based on mecA gene have been detected. In enterococci, linzeolid resistant isolates and isolates with deceased susceptibility to daptomycin have been described. Moreover, ampicillin resistant Enterococcus faecium due to β-lactamase production has been recently found in Europe. Control of MRSA isolates and multiresistant enteroccocci should combined antibiotic stewardship strategies and epidemiological measures, including detection of colonized patients in order to reduce colonization pressure and their transmission.

  1. 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

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

    PubMed

    Vitko, Nicholas P; Richardson, Anthony R

    2013-02-01

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

  3. 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.

  4. 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

  5. Direct Identification of Staphylococcus aureus and Determination of Methicillin Susceptibility From Positive Blood-Culture Bottles in a Bact/ALERT System Using Binax Now S. aureus and PBP2a Tests.

    PubMed

    Heraud, Sandrine; Freydiere, Anne-Marie; Doleans-Jordheim, Anne; Bes, Michèle; Tristan, Anne; Vandenesch, François; Laurent, Frederic; Dauwalder, Olivier

    2015-07-01

    Staphylococcus aureus bacteremia is associated with high mortality and morbidity, requiring prompt and appropriate antimicrobial treatment. Therefore, it is important to detect methicillin-resistant S. aureus (MRSA) rapidly from blood cultures. Two immunochromatographic tests, BinaxNow S. aureus and BinaxNow PBP2a, were directly applied to 79 Bact/Alert bottles that were positive for Gram positive cocci in cluster aggregations. Sensitivity and specificity for the identification of S. aureus and determination of methicillin resistance were 94% and 87%, and 100% and 100%, respectively, with less than 30 min of performance time. These tests are efficient and rapid; these tests are valuable alternatives to more sophisticated and expensive methods used in the diagnosis of MRSA bacteremia.

  6. Direct Identification of Staphylococcus aureus and Determination of Methicillin Susceptibility From Positive Blood-Culture Bottles in a Bact/ALERT System Using Binax Now S. aureus and PBP2a Tests

    PubMed Central

    Heraud, Sandrine; Freydiere, Anne-Marie; Doleans-Jordheim, Anne; Bes, Michèle; Tristan, Anne; Vandenesch, François; Laurent, Frederic

    2015-01-01

    Staphylococcus aureus bacteremia is associated with high mortality and morbidity, requiring prompt and appropriate antimicrobial treatment. Therefore, it is important to detect methicillin-resistant S. aureus (MRSA) rapidly from blood cultures. Two immunochromatographic tests, BinaxNow S. aureus and BinaxNow PBP2a, were directly applied to 79 Bact/Alert bottles that were positive for Gram positive cocci in cluster aggregations. Sensitivity and specificity for the identification of S. aureus and determination of methicillin resistance were 94% and 87%, and 100% and 100%, respectively, with less than 30 min of performance time. These tests are efficient and rapid; these tests are valuable alternatives to more sophisticated and expensive methods used in the diagnosis of MRSA bacteremia. PMID:26131419

  7. Continuous vs. intermittent vancomycin therapy for Gram-positive infections not caused by methicillin-resistant Staphylococcus aureus.

    PubMed

    Duszynska, Wieslawa; Taccone, Fabio S; Hurkacz, Magdalena; Wiela-Hojenska, Anna; Kübler, Andrzej

    2016-03-01

    The aim of this study was to evaluate the effects of vancomycin pharmacokinetics (PKs) on effectiveness and safety in the treatment of Gram-positive infections due to pathogens other than methicillin-resistant Staphylococcus aureus (MRSA). Prospective study including septic patients received either continuous (N.=21) or intermittent (N.=21) infusions of vancomycin; the target drug concentration was 15-20 mg/L and target area under the curve of vancomycin concentrations over the minimum inhibitory concentration of the pathogen on day 1 (AUC24/MIC) >400. Clinical and microbiological responses, the development of acute kidney injury (AKI) and therapy costs were recorded. The median AUC24/MIC was 195(133-343) vs. 189(136-328) mg/L*h in the continuous and intermittent infusion groups. Target drug concentrations were achieved in 15/21 vs. 9/21 (P=0.12) patients and AUC24/MIC>400 in only 5/21 vs. 3/21 (P=0.35) patients of continuous and intermittent groups, respectively. High clinical cure (17/21 for continuous vs. 17/21 for intermittent, P=1.00) and microbiological eradication (17/21 vs. 15/21, P=0.47) were observed in both groups and not associated with drug concentrations or with AUC24/MIC. AKI was diagnosed during therapy in 5/21 patients in the continuous group and 8/21 in the intermittent group (P=0.32). The median total therapy costs were lower in the continuous than in the intermittent group (377 [304-485] vs. 552 [371-644] €, P=0.04). Vancomycin resulted in high clinical response during non-MRSA Gram-positive infections treatment even at drug concentrations lower than those for MRSA. A continuous infusion of vancomycin was associated with a significant reduction in therapy costs compared to intermittent infusions.

  8. 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.

  9. 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

  10. Desiccation tolerance in Staphylococcus aureus.

    PubMed

    Chaibenjawong, Plykaeow; Foster, Simon J

    2011-02-01

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

  11. Evaluation of BD MAX Staph SR Assay for Differentiating Between Staphylococcus aureus and Coagulase-Negative Staphylococci and Determining Methicillin Resistance Directly From Positive Blood Cultures.

    PubMed

    Lee, Jaewoong; Park, Yeon Joon; Park, Dong Jin; Park, Kang Gyun; Lee, Hae Kyung

    2017-01-01

    We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures. From 228 blood culture bottles, 103 S. aureus [45 methicillin-resistant S. aureus (MRSA), 55 methicillin-susceptible S. aureus (MSSA), 3 mixed infections (1 MRSA+Enterococcus faecalis, 1 MSSA+MRCNS, 1 MSSA+MSCNS)], and 125 CNS (102 MRCNS, 23 MSCNS) were identified by Vitek 2. For further analysis, we obtained the cycle threshold (Ct) values from the BD MAX system software to determine an appropriate cutoff value. For discrepancy analysis, conventional mecA/mecC PCR and oxacillin minimum inhibitory concentrations (MICs) were determined. Compared to Vitek 2, the SR assay identified all 103 S. aureus isolates correctly but failed to detect methicillin resistance in three MRSA isolates. All 55 MSSA isolates were correctly identified by the SR assay. In the concordant cases, the highest Ct values for nuc, mecA, and mec right-extremity junction (MREJ) were 25.6, 22, and 22.2, respectively. Therefore, we selected Ct values from 0-27 as a range of positivity, and applying this cutoff, the sensitivity/specificity of the SR assay were 100%/100% for detecting S. aureus, and 97.9%/98.1% and 99.0%/95.8% for detecting methicillin resistance in S. aureus and CNS, respectively. We propose a Ct cutoff value for nuc/mec assay without considering MREJ because mixed cultures of MSSA and MRCNS were very rare (0.4%) in the positive blood cultures.

  12. Peptide signaling in Staphylococcus aureus and other Gram-positive bacteria.

    PubMed

    Lyon, Gholson J; Novick, Richard P

    2004-09-01

    There are two basic types of bacterial communication systems--those in which the signal is directed solely at other organisms and those in which the signal is sensed by the producing organism as well. The former are involved primarily in conjugation; the latter in adaptation to the environment. Gram-positive bacteria use small peptides for both types of signaling, whereas Gram-negative bacteria use homoserine lactones. Since adaptation signals are autoinducers the response is population-density-dependent and has been referred to as "quorum-sensing". Gram-negative bacteria internalize the signals which act upon an intracellular receptor, whereas Gram-positive bacteria use them as ligands for the extracellular receptor of a two-component signaling module. In both cases, the signal activates a complex adaptation response involving many genes.

  13. Spread of Tst-Positive Staphylococcus aureus Strains Belonging to ST30 Clone among Patients and Healthcare Workers in Two Intensive Care Units.

    PubMed

    Papadimitriou-Olivgeris, Matthaios; Drougka, Eleanna; Fligou, Fotini; Dodou, Vasiliki; Kolonitsiou, Fevronia; Filos, Kriton S; Anastassiou, Evangelos D; Petinaki, Efthimia; Marangos, Markos; Spiliopoulou, Iris

    2017-09-04

    Staphylococcus aureus is a major cause of infections. Toxic shock syndrome toxin (TSST-1) and Panton-Valentine leukocidin (PVL) are associated with severe clinical syndromes. S. aureus colonizing isolates recovered from healthcare workers and patients in the intensive care unit (ICU) of a university hospital comprising Group A were compared with those from adult non-ICU carriers (Group B). mecA, lukS/lukF-PV (Panton-Valentine leukocidin, PVL), and tst (toxic shock syndrome toxin) gene carriage was detected by PCR. Clones were identified in all methicillin-resistant S. aureus (MRSA) and toxin-positive methicillin-susceptible strains (MSSA) by pulsed-field gel electrophoresis (PFGE), agr groups, and multi locus sequencing typing (MLST). Group A included 90 S. aureus isolates, whereas Group B 53. PVL was more frequently found among MRSA vs. MSSA (p < 0.001) and in strains of Group B as compared to Group A (p < 0.001), consistent with the spread of ST80-IV. Higher incidence of tst gene carriage was identified among MSSA vs. MRSA (P 0.005) belonging mainly to ST30, and Group A vs. Group B (P 0.002). The wide dissemination of ST80-IV mainly in the community is responsible for a high percentage of PVL-positive MRSA, while silent spread of tst-positive S. aureus clones among ICU patients and personnel poses a threat of hospital transmission and possible severe infections.

  14. Epidemiological profiling of methicillin-resistant Staphylococcus aureus-positive dogs arriving at a veterinary teaching hospital.

    PubMed

    Hoet, Armando E; van Balen, Joany; Nava-Hoet, Rocio C; Bateman, Shane; Hillier, Andrew; Dyce, Jonathan; Wittum, Thomas E

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important zoonotic and nosocomial pathogen in veterinary settings. Even though human risk factors for MRSA infection and colonization are well known, this information in animals is lacking. The objective of this study was to identify risk factors associated with MRSA carrier dogs on their arrival at a veterinary teaching hospital. A total of 435 dogs were enrolled in the MRSA active surveillance program at The Ohio State University-Veterinary Medical Center over a 1-year period. Dogs were screened for MRSA on arrival, regardless of health status, sex, breed, or age. In addition, an epidemiological survey and medical history were obtained for each dog to identify potential risk factors up to 1 year prior to the appointment. Of 435 dogs included in the study, 25 (5.7%) were MRSA positive, with 86.5% of the isolates classified staphylococcal chromosome cassette mec (SCCmec) type II and USA100. Four of the 25 MRSA carrier dogs were healthy, 20 had health issues unrelated to MRSA, and 1 had an active MRSA infection. MRSA was detected in the nares (72%, 18/25), skin lesions (24%, 6/25), and the perianal area (16%, 4/25). Except for previous surgery <90 days (odds ratio [OR]=4.9; 95% confidence interval [CI] 1.4-17.6; p value 0.01), none of the variables related to the previous medical history, dog's management, home environment, and other potential exposures were associated with the MRSA carrier status. However, the profession of the owner was significantly associated, and dogs owned by veterinary students were 20.5 times (95% CI 4.5-93.6; p value≤0.01) more likely to be MRSA positive than dogs owned by clients with different occupations. MRSA-positive dogs were dispersed in different categories, preventing the creation of an epidemiological profile that would allow their early recognition upon arrival to a veterinary hospital. However, the association between veterinary students with MRSA-positive

  15. Clonal diversity and epidemiological characteristics of Staphylococcus aureus: high prevalence of oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) associated with clinical isolates in Brazil.

    PubMed

    Andrade-Figueiredo, Mariana; Leal-Balbino, Tereza Cristina

    2016-06-21

    Staphylococcus aureus is the major cause of global and nosocomial infections with a significant impact in hospitals worldwide. Our objective was to investigate clinical and molecular characteristics of S. aureus isolates causing infections in patients admitted to hospitals from Recife city, Brazil, and investigate the prevalence of oxacillin-susceptible mecA-positive S. aureus (OS-MRSA) in the region, as well as genetically characterize the isolates and compare with epidemic clones. We characterized 89 isolates in total, 31 clinical methicillin-resistant S. aureus (MRSA) and 58 methicillin-sensitive (MSSA) isolates by PFGE, MLST, spa typing and SCCmec genotyping. Isolates belonging to international MRSA clones were present: Brazilian epidemic clone (BEC) (61 % of MRSA isolates), Paediatric (36 %), New York/Japan (3 %). Some MSSA isolates were related to MRSA clones: USA400-related (10 % of MSSA isolates), Berlin clone (2 %), Paediatric (14 %), New York/Japan (2 %) and Southwest Pacific clone (17 %). MLST revealed new sequence types (ST's): ST2381, ST2382, and ST2383 and new spa types: 10548 and 10550. Among isolates phenotypically identified as MSSA by antimicrobial susceptibility assays, we verified 30 oxacillin-susceptible isolates, which exhibited the mecA gene, without mec complex amplification and were thus classified as OS-MRSA. We observed clonal spread of MRSA and MSSA, including OS-MRSA, within several areas of the main hospital investigated and closely related isolates between hospitals analyzed. The results of this study suggest a possible spread of the strains in hospital environment that could be responsible for nosocomial infections. We documented the presence of several MRSA clones, as well as new MLST and spa types, that were responsible for severe infections in hospitalized patients. The finding of OS-MRSA isolates could have implications for therapy, because testing for mecA and PBP2a is not a routine procedure performed by clinical

  16. 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.

  17. Exfoliative Toxins of Staphylococcus aureus

    PubMed Central

    Bukowski, Michal; Wladyka, Benedykt; Dubin, Grzegorz

    2010-01-01

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

  18. 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.

  19. Alternative fluorescent labeling strategies for characterizing gram-positive pathogenic bacteria: Flow cytometry supported counting, sorting, and proteome analysis of Staphylococcus aureus retrieved from infected host cells.

    PubMed

    Hildebrandt, Petra; Surmann, Kristin; Salazar, Manuela Gesell; Normann, Nicole; Völker, Uwe; Schmidt, Frank

    2016-10-01

    Staphylococcus aureus is a Gram-positive opportunistic pathogen that is able to cause a broad range of infectious diseases in humans. Furthermore, S. aureus is able to survive inside nonprofessional phagocytic host cell which serve as a niche for the pathogen to hide from the immune system and antibiotics therapies. Modern OMICs technologies provide valuable tools to investigate host-pathogen interactions upon internalization. However, these experiments are often hampered by limited capabilities to retrieve bacteria from such an experimental setting. Thus, the aim of this study was to develop a labeling strategy allowing fast detection and quantitation of S. aureus in cell lysates or infected cell lines by flow cytometry for subsequent proteome analyses. Therefore, S. aureus cells were labeled with the DNA stain SYTO(®) 9, or Vancomycin BODIPY(®) FL (VMB), a glycopeptide antibiotic binding to most Gram-positive bacteria which was conjugated to a fluorescent dye. Staining of S. aureus HG001 with SYTO 9 allowed counting of bacteria from pure cultures but not in cell lysates from infection experiments. In contrast, with VMB it was feasible to stain bacteria from pure cultures as well as from samples of infection experiments. VMB can also be applied for histocytochemistry analysis of formaldehyde fixed cell layers grown on coverslips. Proteome analyses of S. aureus labeled with VMB revealed that the labeling procedure provoked only minor changes on proteome level and allowed cell sorting and analysis of S. aureus from infection settings with sensitivity similar to continuous gfp expression. Furthermore, VMB labeling allowed precise counting of internalized bacteria and can be employed for downstream analyses, e.g., proteomics, of strains not easily amendable to genetic manipulation such as clinical isolates. © 2016 International Society for Advancement of Cytometry.

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

    PubMed

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

    2015-04-01

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

  1. Methicillin-resistant Staphylococcus aureus: the superbug.

    PubMed

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

    2010-10-01

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

  2. Rapid Detection of Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus Directly from Positive Blood Cultures by Use of the BD Max StaphSR Assay

    PubMed Central

    Olma, Tom; O'Sullivan, Matthew V. N.

    2015-01-01

    The BD Max StaphSR assay is an automated qualitative in vitro diagnostic test for the direct detection and differentiation of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). A total of 460 specimens were tested, and the results were compared with standard culture-based identification. MRSA was detected in 48 samples (sensitivity of 100%; positive predictive value [PPV] of 100%). MSSA was detected in 112 samples (sensitivity of 99.1%; PPV of 100%), and 299 samples containing coagulase-negative staphylococcus and nonstaphylococcal species were negative by the BD Max StaphSR assay (specificity of 100%; negative predictive value [NPV] of 99.7 to 100%). PMID:26400789

  3. Catheter-associated Staphylococcus aureus bacteremia.

    PubMed

    Gold, H S; Karchmer, A W

    1996-09-15

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

  4. An International, Prospective, Multicenter Evaluation of the Combination of AdvanDx Staphylococcus QuickFISH BC with mecA XpressFISH for Detection of Methicillin-Resistant Staphylococcus aureus Isolates from Positive Blood Cultures

    PubMed Central

    Salimnia, H.; Lephart, P.; Morgan, M.; Gilbreath, J. J.; Butler-Wu, S. M.; Templeton, K. E.; Hamilton, F. J.; Wu, F.; Buckner, R.; Fuller, D.; Davis, T. E.; Abdelhamed, A. M.; Jacobs, M. R.; Miller, A.; Pfrommer, B.; Carroll, K. C.

    2014-01-01

    Sepsis caused by Staphylococcus aureus is a major health problem worldwide. Better outcomes are achieved when rapid diagnosis and determination of methicillin susceptibility enable early optimization of antimicrobial therapy. Eight large clinical laboratories, seven from the United States and one from Scotland, evaluated the combination of the Staphylococcus QuickFISH BC and the new mecA XpressFISH assay (both AdvanDx, Woburn, MA, USA) for the detection of methicillin-resistant S. aureus in positive blood cultures. Blood cultures flagged as positive by automated blood culture instruments and demonstrating only Gram-positive cocci in clusters on Gram stain were tested by QuickFISH, a 20-min assay. If only S. aureus was detected, mecA XpressFISH testing followed. The recovered S. aureus isolates were tested by cefoxitin disk diffusion as the reference method. The QuickFISH assay results were concordant with the routine phenotypic testing methods of the testing laboratories in 1,211/1,221 (99.1%) samples and detected 488/491 S. aureus organisms (sensitivity, 99.4%; specificity, 99.6%). Approximately 60% of the samples (730) contained coagulase-negative staphylococci or nonstaphylococci as assessed by the QuickFISH assay and were not tested further. The 458 compliant samples positive exclusively for S. aureus by the QuickFISH assay were tested by the mecA XpressFISH assay, which detected 209 of 211 methicillin-resistant S. aureus organisms (sensitivity, 99.1%; specificity, 99.6%). The mecA XpressFISH assay also showed high reproducibility, with 534/540 tests performed by 6 operators over 5 days achieving reproducible results (98.9% agreement). The combination of the Staphylococcus QuickFISH BC and mecA XpressFISH assays is sensitive, specific, and reproducible for the detection of methicillin-resistant S. aureus and yields complete results in 2 h after the blood culture turns positive. PMID:25165083

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

    PubMed

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

    1996-01-01

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

  6. Outbreak of Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus in a regional burns unit.

    PubMed

    Teare, L; Shelley, O P; Millership, S; Kearns, A

    2010-11-01

    Over a 16 month period, 30 individuals (19 patients, one relative and 10 members of staff) on a regional burns and plastics unit became colonised or infected with a single strain of Panton-Valentine leucocidin-producing meticillin-resistant Staphylococcus aureus (PVL-MRSA). The strain was resistant to ciprofloxacin, neomycin and gentamicin and belonged to a community-associated MRSA lineage known to be circulating in the UK. The outbreak occurred in four stages, the first being in burns outpatients, the second and third being on the burns unit itself and the final stage on a plastics ward. In spite of closing the affected unit and deep cleaning, including steam cleaning and hydrogen peroxide treatment, the outbreak continued. It was not until staff carriage was fully addressed that the outbreak was controlled.

  7. Mechanisms of antibiotic resistance in Staphylococcus aureus.

    PubMed

    Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

    2007-06-01

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

  8. 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

  9. Natural product derivatives with bactericidal activity against Gram-positive pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis.

    PubMed

    Phillips, Joshua B; Smith, Adrienne E; Kusche, Brian R; Bessette, Bradley A; Swain, P Whitney; Bergmeier, Stephen C; McMills, Mark C; Wright, Dennis L; Priestley, Nigel D

    2010-10-01

    We have shown that the intentional engineering of a natural product biosynthesis pathway is a useful way to generate stereochemically complex scaffolds for use in the generation of combinatorial libraries that capture the structural features of both natural products and synthetic compounds. Analysis of a prototype library based upon nonactic acid lead to the discovery of triazole-containing nonactic acid analogs, a new structural class of antibiotic that exhibits bactericidal activity against drug resistant, Gram-positive pathogens including Staphylococcus aureus and Enterococcus faecalis.

  10. 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

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

    PubMed Central

    2012-01-01

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

  12. Expansion of a plasmid classification system for Gram-positive bacteria and determination of the diversity of plasmids in Staphylococcus aureus strains of human, animal, and food origins.

    PubMed

    Lozano, Carmen; García-Migura, Lourdes; Aspiroz, Carmen; Zarazaga, Myriam; Torres, Carmen; Aarestrup, Frank Møller

    2012-08-01

    An expansion of a previously described plasmid classification was performed and used to reveal the plasmid content of a collection of 92 Staphylococcus aureus strains of different origins. rep genes of other genera were detected in Staphylococcus. S1 pulsed-field gel electrophoresis (PFGE) hybridizations were performed with 18 representative S. aureus strains, and a high number of plasmids of different sizes and organizations were detected.

  13. Contrasting Effects of Acidic pH on the Extracellular and Intracellular Activities of the Anti-Gram-Positive Fluoroquinolones Moxifloxacin and Delafloxacin against Staphylococcus aureus ▿ †

    PubMed Central

    Lemaire, Sandrine; Tulkens, Paul M.; Van Bambeke, Françoise

    2011-01-01

    In contrast to currently marketed fluoroquinolones, which are zwitterionic, delafloxacin is an investigational fluoroquinolone with an anionic character that is highly active against Gram-positive bacteria. We have examined the effect of acidic pH on its accumulation in Staphylococcus aureus and in human THP-1 cells, in parallel with its activity against extracellular and intracellular S. aureus. Moxifloxacin was used as a comparator. Delafloxacin showed MICs 3 to 5 log2 dilutions lower than those of moxifloxacin for a collection of 35 strains with relevant resistance mechanisms and also proved to be 10-fold more potent against intracellular S. aureus ATCC 25923. In medium at pH 5.5, this difference was further enhanced, with the MIC decreasing by 5 log2 dilutions. In infected cells incubated in acidic medium, the relative potency was 10-fold higher than that at neutral pH and the maximal relative efficacy reached a bactericidal effect at 24 h. These results can be explained by a 10-fold increase in delafloxacin accumulation in both bacteria and cells at acidic pH, making delafloxacin one of the most efficient drugs tested in this model. Opposite effects were seen for moxifloxacin with respect to both activity and accumulation. As reported for zwitterionic fluoroquinolones, delafloxacin was found associated with the soluble fraction in homogenates of eukaryotic cells. Taken together, these properties may confer to delafloxacin an advantage for the eradication of S. aureus in acidic environments, including intracellular infections. PMID:21135179

  14. Comparison of killing of gram-negative and gram-positive bacteria by pure singlet oxygen. [Salmonella typhimurium; Escherichia coli; Sarcina lutea; Staphylococcus aureus; Streptococcus lactis; Streptococcus faecalis

    SciTech Connect

    Dahl, T.A.; Midden, W.R. ); Hartman, P.E. )

    1989-04-01

    Gram-negative and gram-positive bacteria were found to display different sensitivities to pure singlet oxygen generated outside of cells. Killing curves for Salmonella typhimurium and Escherichia coli strains were indicative of multihit killing, whereas curves for Sarcina lutea, Staphylococcus aureus, Streptococcus lactis, and Streptococcus faecalis exhibited single-hit kinetics. The S. typhimurium deep rough strain TA1975, which lacks nearly all of the cell wall lipopolysaccharide coat and manifests concomitant enhancement of penetration by some exogenous substances, responded to singlet oxygen with initially faster inactivation than did the S. typhimurium wild-type strain, although the maximum rates of killing appeared to be quite similar. The structure of the cell wall thus plays an important role in susceptibility to singlet oxygen. The outer membrane-lipopolysaccharide portion of the gram-negative cell wall initially protects the bacteria from extracellular singlet oxygen, although it may also serve as a source for secondary reaction products which accentuate the rates of cell killing. S. typhimurium and E. coli strains lacking the cellular antioxidant, glutathione, showed no difference from strains containing glutathione in response to the toxic effects of singlet oxygen. Strains of Sarcina lutea and Staphylococcus aureus that contained carotenoids, however, were far more resistant to singlet oxygen lethality than were both carotenoidless mutants of the same species and other gram-positive species lacking high levels of protective carotenoids.

  15. Development of a rapid diagnostic method for identification of Staphylococcus aureus and antimicrobial resistance in positive blood culture bottles using a PCR-DNA-chromatography method.

    PubMed

    Ohshiro, Takeya; Miyagi, Chihiro; Tamaki, Yoshikazu; Mizuno, Takuya; Ezaki, Takayuki

    2016-06-01

    Blood culturing and the rapid reporting of results are essential for infectious disease clinics to obtain bacterial information that can affect patient prognosis. When gram-positive coccoid cells are observed in blood culture bottles, it is important to determine whether the strain is Staphylococcus aureus and whether the strain has resistance genes, such as mecA and blaZ, for proper antibiotic selection. Previous work led to the development of a PCR method that is useful for rapid identification of bacterial species and antimicrobial susceptibility. However, that method has not yet been adopted in community hospitals due to the high cost and methodological complexity. We report here the development of a quick PCR and DNA-chromatography test, based on single-tag hybridization chromatography, that permits detection of S. aureus and the mecA and blaZ genes; results can be obtained within 1 h for positive blood culture bottles. We evaluated this method using 42 clinical isolates. Detection of S. aureus and the resistance genes by the PCR-DNA-chromatography method was compared with that obtained via the conventional identification method and actual antimicrobial susceptibility testing. Our method had a sensitivity of 97.0% and a specificity of 100% for the identification of the bacterial species. For the detection of the mecA gene of S. aureus, the sensitivity was 100% and the specificity was 95.2%. For the detection of the blaZ gene of S. aureus, the sensitivity was 100% and the specificity was 88.9%. The speed and simplicity of this PCR-DNA-chromatography method suggest that our method will facilitate rapid diagnoses. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  16. 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

  17. Panton-valentine leukocidin-positive and toxic shock syndrome toxin 1-positive methicillin-resistant Staphylococcus aureus: a French multicenter prospective study in 2008.

    PubMed

    Robert, Jérôme; Tristan, Anne; Cavalié, Laurent; Decousser, Jean-Winoc; Bes, Michèle; Etienne, Jerome; Laurent, Frédéric

    2011-04-01

    The epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) differs from country to country. We assess the features of the ST80 European clone, which is the most prevalent PVL-positive CA-MRSA clone in Europe, and the TSST-1 ST5 clone that was recently described in France. In 2008, all MRSA strains susceptible to fluoroquinolones and gentamicin and resistant to fusidic acid that were isolated in 104 French laboratories were characterized using agr alleles, spa typing, and the staphylococcal cassette chromosome mec element and PCR profiling of 21 toxin genes. Three phenotypes were defined: (i) kanamycin resistant, associated with the ST80 clone; (ii) kanamycin and tobramycin resistant, associated with the ST5 clone; and (iii) aminoglycoside susceptible, which was less frequently associated with the ST5 clone. Among the 7,253 MRSA strains isolated, 91 (1.3%) were ST80 CA-MRSA (89 phenotype 1) and 190 (2.6%) were ST5 CA-MRSA (146 phenotype 2, 42 phenotype 3). Compared to the latter, ST80 CA-MRSAs were more likely to be community acquired (80% versus 46%) and found in young patients (median age, 26.0 years versus 49.5 years) with deep cutaneous infections (48% versus 6%). They were less likely to be tetracycline susceptible (22% versus 85%) and to be isolated from respiratory infections (6% versus 27%). The TSST-1 ST5 clone has rapidly emerged in France and has become even more prevalent than the ST80 European clone, whose prevalence has remained stable. The epidemiological and clinical patterns of the two clones differ drastically. Given the low prevalence of both among all staphylococcal infections, no modification of antibiotic recommendations is required yet.

  18. Panton-Valentine Leukocidin-Positive and Toxic Shock Syndrome Toxin 1-Positive Methicillin-Resistant Staphylococcus aureus: a French Multicenter Prospective Study in 2008▿

    PubMed Central

    Robert, Jérôme; Tristan, Anne; Cavalié, Laurent; Decousser, Jean-Winoc; Bes, Michèle; Etienne, Jerome; Laurent, Frédéric

    2011-01-01

    The epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) differs from country to country. We assess the features of the ST80 European clone, which is the most prevalent PVL-positive CA-MRSA clone in Europe, and the TSST-1 ST5 clone that was recently described in France. In 2008, all MRSA strains susceptible to fluoroquinolones and gentamicin and resistant to fusidic acid that were isolated in 104 French laboratories were characterized using agr alleles, spa typing, and the staphylococcal cassette chromosome mec element and PCR profiling of 21 toxin genes. Three phenotypes were defined: (i) kanamycin resistant, associated with the ST80 clone; (ii) kanamycin and tobramycin resistant, associated with the ST5 clone; and (iii) aminoglycoside susceptible, which was less frequently associated with the ST5 clone. Among the 7,253 MRSA strains isolated, 91 (1.3%) were ST80 CA-MRSA (89 phenotype 1) and 190 (2.6%) were ST5 CA-MRSA (146 phenotype 2, 42 phenotype 3). Compared to the latter, ST80 CA-MRSAs were more likely to be community acquired (80% versus 46%) and found in young patients (median age, 26.0 years versus 49.5 years) with deep cutaneous infections (48% versus 6%). They were less likely to be tetracycline susceptible (22% versus 85%) and to be isolated from respiratory infections (6% versus 27%). The TSST-1 ST5 clone has rapidly emerged in France and has become even more prevalent than the ST80 European clone, whose prevalence has remained stable. The epidemiological and clinical patterns of the two clones differ drastically. Given the low prevalence of both among all staphylococcal infections, no modification of antibiotic recommendations is required yet. PMID:21220529

  19. 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

  20. 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.

  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. Molecular Typing and Virulence Gene Profiles of Enterotoxin Gene Cluster (egc)-Positive Staphylococcus aureus Isolates Obtained from Various Food and Clinical Specimens.

    PubMed

    Song, Minghui; Shi, Chunlei; Xu, Xuebing; Shi, Xianming

    2016-11-01

    The enterotoxin gene cluster (egc) has been proposed to contribute to the Staphylococcus aureus colonization, which highlights the need to evaluate genetic diversity and virulence gene profiles of the egc-positive population. Here, a total of 43 egc-positive isolates (16.2%) were identified from 266 S. aureus isolates that were obtained from various food and clinical specimens in Shanghai. Seven different egc profiles were found based on the polymerase chain reaction (PCR) result for egc genes. Then, these 43 egc-positive isolates were further typed by multilocus sequence typing, pulsed-field gel electrophoresis (PFGE), multiple-locus variable-number tandem-repeat analysis (MLVA), and accessory gene regulatory (agr) typing. It showed that the 43 egc-positive isolates displayed 17 sequence types, 28 PFGE patterns, 29 MLVA types, and 4 agr types, respectively. Among them, the dominant clonal lineage was CC5-agr II (48.84%). Thirty toxin and 20 adhesion-associated genes were detected by PCR in egc-positive isolates. Notably, invasive toxin genes showed a high prevalence, such as 76.7% for Panton-Valentine leukocidin encoding genes, 27.9% for sec, and 23.3% for tsst-1. Most of the examined adhesion-associated genes were found to be conserved (76.7-100%), whereas the fnbB gene was only found in 8 (18.6%) isolates. In addition, 33 toxin gene profiles and 13 adhesion gene profiles were identified, respectively. Our results imply that isolates belonging to the same clonal lineage harbored similar adhesion gene profiles but diverse toxin gene profiles. Overall, the high prevalence of invasive virulence genes increases the potential risk of egc-positive isolates in S. aureus infection.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. Detection of ST772 Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (Bengal Bay clone) and ST22 S. aureus isolates with a genetic variant of elastin binding protein in Nepal

    PubMed Central

    Pokhrel, R.H.; Aung, M.S.; Thapa, B.; Chaudhary, R.; Mishra, S.K.; Kawaguchiya, M.; Urushibara, N.; Kobayashi, N.

    2016-01-01

    Genetic characteristics were analysed for recent clinical isolates of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA respectively) in Kathmandu, Nepal. MRSA isolates harbouring Panton-Valentine leukocidin (PVL) genes were classified into ST1, ST22 and ST88 with SCCmec-IV and ST772 with SCCmec-V (Bengal Bay clone), while PVL-positive MSSA into ST22, ST30 and ST772. ST22 isolates (PVL-positive MRSA and MSSA, PVL-negative MRSA) possessed a variant of elastin binding protein gene (ebpS) with an internal deletion of 180 bp, which was similar to that reported for ST121 S. aureus previously outside Nepal. Phylogenetic analysis indicated that the ebpS variant in ST22 might have occurred independently of ST121 strains. This is the first report of ST772 PVL-positive MRSA in Nepal and detection of the deletion variant of ebpS in ST22 S. aureus. PMID:27014464

  9. 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.

  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. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  11. Hemoglobin Promotes Staphylococcus aureus Nasal Colonization

    PubMed Central

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

    2011-01-01

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

  12. VanA and VanB Positive Vancomycin-resistant Staphylococcus aureus Among Clinical Isolates in Shiraz, South of Iran

    PubMed Central

    Saadat, Sareh; Solhjoo, Kavous; Norooz-Nejad, Mohammad-Javad; Kazemi, Akbar

    2014-01-01

    Objective The purpose of this study was to determine the prevalence of vancomycin-resistant Staphylococcus aureus isolated from clinical samples in Shiraz hospitals. Methods From March to December 2012, 100 S. aureus isolates (mainly from wound and blood) were collected from three hospitals in Shiraz, south of Iran. After identification of Staphylococcus aureus by biochemical, microbiological and molecular methods, antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion test for 13 different antibiotics. Vancomycin-resistant Staphylococcus aureus isolates were determined by vancomycin agar screening test and PCR for vancomycin resistant genes (vanA and vanB). Results The lowest and highest resistance was seen for quinupristin-dalfopristin (n=1) and ampicillin (n=95), respectively. Vancomycin agar screening test showed that 37 isolates can grow on these media. Further study by PCR also detected vanA and/or vanB genes in all of these strains. Also, 19 isolates showed either vanA or vanB but were susceptible according to vancomycin agar screening test. In total, vanA and vanB resistant genes were detected in 34% and 37% of clinical isolates, respectively. Conclusion The results showed that the frequency of vancomycin resistance genes (vanA, vanB) is very high in Staphylococcus aureus strains isolated from patients in south of Iran. Thus, urgent interventions are needed to keep the emergence and transmission of these isolates to a minimum. PMID:25337309

  13. [Presence of fecal coliforms, Escherichia coli and DNAse- and coagulase-positive Staphylococcus aureus, in "colonial" cheese sold in the city of Blumenau, Estado de Santa Catarina, Brazil].

    PubMed

    Reibnitz, M G; Tavares, L B; García, J A

    1998-01-01

    Twenty cheese samples were collected at Blumenau (SC) and were submitted to analysis in order to verify the presence of fecal coliforms, Escherichia coli and Staphylococcus aureus. Among the 20 samples of cheese, analysis revealed that 70% and 20% respectively, were not within present legal specifications (Norma 001/87-DNVSA) for fecal coliforms and Escherichia coli. For Staphylococcus, 95% of the samples were not within present legal specifications.

  14. Nasal carriage of multi-drug resistant Panton-Valentine leucocidin-positive methicillin-resistant Staphylococcus aureus in children in Tripoli-Libya.

    PubMed

    Al-haddad, Omaima H; Zorgani, Abdulaziz; Ghenghesh, Khalifa Sifaw

    2014-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.

  15. Cytoplasmic peptidoglycan intermediate levels in Staphylococcus aureus.

    PubMed

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

    2016-02-01

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

  16. Panton-Valentine Leukocidin-Positive Staphylococcus aureus in Ireland from 2002 to 2011: 21 Clones, Frequent Importation of Clones, Temporal Shifts of Predominant Methicillin-Resistant S. aureus Clones, and Increasing Multiresistance

    PubMed Central

    Shore, Anna C.; Tecklenborg, Sarah C.; Brennan, Gráinne I.; Ehricht, Ralf; Monecke, Stefan

    2014-01-01

    There has been a worldwide increase in community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) infections. CA-MRSA isolates commonly produce the Panton-Valentine leukocidin toxin encoded by the pvl genes lukF-PV and lukS-PV. This study investigated the clinical and molecular epidemiologies of pvl-positive MRSA and methicillin-susceptible S. aureus (MSSA) isolates identified by the Irish National MRSA Reference Laboratory (NMRSARL) between 2002 and 2011. All pvl-positive MRSA (n = 190) and MSSA (n = 39) isolates underwent antibiogram-resistogram typing, spa typing, and DNA microarray profiling for multilocus sequence type, clonal complex (CC) and/or sequence type (ST), staphylococcal cassette chromosome mec type assignment, and virulence and resistance gene detection. Where available, patient demographics and clinical data were analyzed. The prevalence of pvl-positive MRSA increased from 0.2% to 8.8%, and that of pvl-positive MSSA decreased from 20% to 2.5% during the study period. The pvl-positive MRSA and MSSA isolates belonged to 16 and 5 genotypes, respectively, with CC/ST8-MRSA-IV, CC/ST30-MRSA-IV, CC/ST80-MRSA-IV, CC1/ST772-MRSA-V, CC30-MSSA, CC22-MSSA, and CC121-MSSA predominating. Temporal shifts in the predominant pvl-positive MRSA genotypes and a 6-fold increase in multiresistant pvl-positive MRSA genotypes occurred during the study period. An analysis of patient data indicated that pvl-positive S. aureus strains, especially MRSA strains, had been imported into Ireland several times. Two hospital and six family clusters of pvl-positive MRSA were identified, and 70% of the patient isolates for which information was available were from patients in the community. This study highlights the increased burden and changing molecular epidemiology of pvl-positive S. aureus in Ireland over the last decade and the contribution of international travel to the influx of genetically diverse pvl-positive S. aureus isolates into Ireland. PMID:24371244

  17. Comparison of genomic and antimicrobial resistance features of latex agglutination test-positive and latex agglutination test-negative Staphylococcus aureus isolates causing bovine mastitis.

    PubMed

    Moser, A; Stephan, R; Corti, S; Johler, S

    2013-01-01

    The dairy industry suffers massive economic losses due to staphylococcal mastitis in cattle. The Staphaureux latex agglutination test (Oxoid, Basel, Switzerland) was reported to lead to negative results in 54% of bovine Staphylococcus aureus strains, and latex-negative strains are thought to be less virulent than Staphaurex latex-positive strains. However, comparative information on virulence and resistance profiles of these 2 groups of Staph. aureus is scarce. Our objective was to associate the latex agglutination phenotype of Staph. aureus strains isolated from bovine mastitis milk with data on clonal complexes, virulence genes, and antibiotic resistance to (1) determine the virulence profiles of the Staphaureux test positive and Staphaurex test negative groups, and (2) provide data needed to improve treatment of bovine mastitis and to identify potential vaccine targets. Seventy-eight Staph. aureus strains isolated from 78 cows on 57 Swiss farms were characterized. Latex agglutination was tested by Staphaureux kit, and resistance profiles were generated by disk diffusion. A DNA microarray was used to assign clonal complexes (CC) and to determine virulence and resistance gene profiles. By the Staphaureux test, 49% of the isolates were latex-positive and 51% were latex-negative. All latex-negative strains were assigned to CC151, whereas latex-positive strains were assigned to various clonal complexes, including CC97 (n=16), CC8 (n=10), CC479 (n=5), CC20 (n=4), CC7 (n=1), CC9 (n=1), and CC45 (n=1). Although the latex-negative isolates were susceptible to all antimicrobial agents tested, 24% of latex-positive isolates were classified as intermediate with regard to cefalexin-kanamycin and 13% were resistant to both ampicillin and penicillin. Microarray profiles of latex-negative isolates were highly similar, but differed largely from those of latex-positive isolates. Although the latex-negative group lacked several enterotoxin genes and sak, it exhibited significantly

  18. 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.

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

    PubMed Central

    2010-01-01

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

  20. 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%.

  1. An Improved Medium for Growing Staphylococcus aureus Biofilm

    DTIC Science & Technology

    2012-04-19

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

  2. Noncontiguous Finished Genome Sequence of Staphylococcus aureus KLT6, a Staphylococcal Enterotoxin B-Positive Strain Involved in a Food Poisoning Outbreak in Switzerland

    PubMed Central

    Tobes, Raquel; Manrique, Marina; Brozynska, Marta; Stephan, Roger; Pareja, Eduardo

    2013-01-01

    We present the first complete genome sequence of a Staphylococcus aureus strain assigned to clonal complex 12. The strain was isolated in a food poisoning outbreak due to contaminated potato salad in Switzerland in 2009, and it produces staphylococcal enterotoxin B. PMID:23704175

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

    PubMed

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

    2017-08-01

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

  4. Repression of Staphylococcus aureus by Food Bacteria

    PubMed Central

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

    1963-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  6. 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

  7. 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.

  8. Epidemiology of Staphylococcus aureus during space flight.

    PubMed

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

    1996-12-31

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

  9. 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

  10. BDCA1-Positive Dendritic Cells (DCs) Represent a Unique Human Myeloid DC Subset That Induces Innate and Adaptive Immune Responses to Staphylococcus aureus Infection

    PubMed Central

    Zhang, Wei; Du, Jiang-yuan; Yu, Qing

    2014-01-01

    Staphylococcus aureus bloodstream infection (bacteremia) is a major cause of morbidity and mortality and places substantial cost burdens on health care systems. The role of peripheral blood dendritic cells (PBDCs) in the immune responses against S. aureus infection has not been well characterized. In this study, we demonstrated that BDCA1+ myeloid DCs (mDCs) represent a unique PBDC subset that can induce immune responses against S. aureus infection. BDCA1+ mDCs could engulf S. aureus and strongly upregulated the expression of costimulatory molecules and production of proinflammatory cytokines. Furthermore, BDCA1+ mDCs expressed high levels of major histocompatibility complex (MHC) class I and II molecules in response to S. aureus and greatly promoted proliferation and gamma interferon (IFN-γ) production in CD4 and CD8 T cells. Moreover, BDCA1+ mDCs expressed higher levels of Toll-like receptor 2 (TLR-2) and scavenger receptor A (SR-A) than those on CD16+ and BDCA3+ mDCs, and these two receptors were both required for the recognition of S. aureus and the subsequent activation of BDCA1+ mDCs. Finally, BDCA1+ mDC-mediated immune responses against S. aureus were dependent on MyD88 signaling pathways. These results demonstrate that human BDCA1+ mDCs represent a unique subset of mDCs that can respond to S. aureus to undergo maturation and activation and to induce Th1 and Tc1 immune responses. PMID:25114114

  11. 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.

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

    PubMed

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

    2017-02-01

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

  13. Population Structure of Staphylococcus aureus from Trinidad & Tobago

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2013-11-01

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

  15. 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.

  16. High Rate of qacA- and qacB-Positive Methicillin-Resistant Staphylococcus aureus Isolates from Chlorhexidine-Impregnated Catheter-Related Bloodstream Infections

    PubMed Central

    Ho, Cheng-Mao; Li, Chi-Yuan; Ho, Mao-Wang; Lin, Chien-Yu; Liu, Shu-Hui

    2012-01-01

    Chlorhexidine has been widely used for infection control. Although the use of chlorhexidine-impregnated catheters has reduced catheter-related infections, chlorhexidine-resistant Staphylococcus aureus has emerged. The correlation between the existence of the chlorhexidine-resistant genes qacA and qacB (qacA/B) in methicillin-resistant Staphylococcus aureus (MRSA) isolates and the effectiveness of chlorhexidine-impregnated catheters in the prevention of MRSA infections is unknown. Sixty methicillin-sensitive Staphylococcus aureus (MSSA) and 96 MRSA isolates from the blood cultures of different patients were collected, and a case-control study was conducted to determine whether more clinical S. aureus isolates from chlorhexidine-impregnated catheter-related bloodstream infections (CRBSI) have the biocide-resistant genes (qacA/B or smr) than those from other infections. The chlorhexidine MIC50s of MSSA and MRSA isolates were 1 μg/ml and 2 μg/ml, respectively. Results of PCR analyses showed that 3.3% (n = 2) of MSSA and 43.8% (n = 42) of MRSA isolates harbored qacA/B and 5% (n = 3) of MSSA and 25% (n = 24) of MRSA isolates contained smr. With multivariate logistic regression analyses, the significant risk factors for definite CRBSI with chlorhexidine-impregnated catheters were determined to be S. aureus isolates with qacA/B and a chlorhexidine MIC of ≥2 μg/ml (odds ratios [OR], 9.264 and 8.137, respectively, in all 156 S. aureus isolates and 6.097 and 4.373, respectively, in the 96 MRSA isolates). Further prospective studies are needed to investigate the transmission of these biocide-resistant genes. PMID:22908163

  17. The Staphylococcus aureus “superbug”

    PubMed Central

    Foster, Timothy J.

    2004-01-01

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

  18. TOLERANCE OF STAPHYLOCOCCUS AUREUS TO SODIUM CHLORIDE

    PubMed Central

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

    1964-01-01

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

  19. Identification and characterization of linezolid-resistant cfr-positive Staphylococcus aureus USA300 isolates from a New York City medical center.

    PubMed

    Locke, Jeffrey B; Zuill, Douglas E; Scharn, Caitlyn R; Deane, Jennifer; Sahm, Daniel F; Goering, Richard V; Jenkins, Stephen G; Shaw, Karen J

    2014-11-01

    The cfr gene was identified in three linezolid-resistant USA300 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected over a 3-day period at a New York City medical center in 2011 as part of a routine surveillance program. Each isolate possessed a plasmid containing a pSCFS3-like cfr gene environment. Transformation of the cfr-bearing plasmids into the S. aureus ATCC 29213 background recapitulated the expected Cfr antibiogram, including resistance to linezolid, tiamulin, clindamycin, and florfenicol and susceptibility to tedizolid. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Identification and Characterization of Linezolid-Resistant cfr-Positive Staphylococcus aureus USA300 Isolates from a New York City Medical Center

    PubMed Central

    Zuill, Douglas E.; Scharn, Caitlyn R.; Deane, Jennifer; Sahm, Daniel F.; Goering, Richard V.; Jenkins, Stephen G.; Shaw, Karen J.

    2014-01-01

    The cfr gene was identified in three linezolid-resistant USA300 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected over a 3-day period at a New York City medical center in 2011 as part of a routine surveillance program. Each isolate possessed a plasmid containing a pSCFS3-like cfr gene environment. Transformation of the cfr-bearing plasmids into the S. aureus ATCC 29213 background recapitulated the expected Cfr antibiogram, including resistance to linezolid, tiamulin, clindamycin, and florfenicol and susceptibility to tedizolid. PMID:25136008

  1. Trial to control an outbreak of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus at a boarding school in Japan.

    PubMed

    Higashiyama, Masaaki; Ito, Teruyo; Han, Xiao; Nishiyama, Junichiro; Tanno, Akemi; Wada, Toshiko; Funaoka, Youichi; Yoshida, Yusuke; Mikita, Kei; Ogawa, Tomomichi; Okusa, Yasushi; Kaku, Koki; Hatada, Junichi; Hiramatsu, Keiichi; Kawana, Akihiko

    2011-12-01

    Our retrospective investigation of methicillin-resistant Staphylococcus aureus (MRSA) infection at a hospital in Japan around 2007 suggested dissemination of community-associated MRSA (CA-MRSA) strains among healthy students in a Japanese boarding school, which frequently caused skin disease and exhibited the same antibiogram patterns. Active surveillance of skin diseases for 6 months after May 2008, examination of MRSA carriage in selected high-risk groups, and investigation of their life circumstances, including environmental cultures, were conducted in the school. Furthermore, we strengthened hygiene practices and improved recognized risk factors from November 2008 and observed the occurrence of skin diseases and MRSA carriage rate for the evaluation of infection controls. We identified 21 patients with skin diseases in whom MRSA strains were isolated. MRSA colonization rates in 3 selected groups ranged from 7.6% to 36.6%. The rates of both skin disease and MRSA carriage decreased significantly after infection controls were introduced. Genetic analysis revealed a main dissemination of a PVL-positive SCCmec IVc clone (41/47 isolates in total), presenting as a different pulsed-field type than USA300. This first report of a PVL-positive CA-MRSA outbreak in Japan demonstrates systematic management of dissemination by conducting surveillance in a closed community. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  2. Current concepts in antimicrobial therapy against select gram-positive organisms: methicillin-resistant Staphylococcus aureus, penicillin-resistant pneumococci, and vancomycin-resistant enterococci.

    PubMed

    Rivera, Ana Maria; Boucher, Helen W

    2011-12-01

    Gram-positive bacteria cause a broad spectrum of disease in immunocompetent and immunocompromised hosts. Despite increasing knowledge about resistance transmission patterns and new antibiotics, these organisms continue to cause significant morbidity and mortality, especially in the health care setting. Methicillin-resistant Staphylococcus aureus poses major problems worldwide as a cause of nosocomial infection and has emerged as a cause of community-acquired infections. This change in epidemiology affects choices of empirical antibiotics for skin and skin-structure infections and community-acquired pneumonia in many settings. Throughout the world, the treatment of community-acquired pneumonia and other respiratory tract infections caused by penicillin-resistant Streptococcus pneumoniae has been complicated by resistance to β-lactam and macrolide antibacterial drugs. Vancomycin-resistant enterococci are a major cause of infection in the hospital setting and remain resistant to treatment with most standard antibiotics. Treatment of diseases caused by resistant gram-positive bacteria requires appropriate use of available antibiotics and stewardship to prolong their effectiveness. In addition, appropriate and aggressive infection control efforts are vital to help prevent the spread of resistant pathogens.

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

    PubMed

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

    2015-02-01

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

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

    PubMed Central

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

    2017-01-01

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

  5. 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

  6. Staphylococcus aureus dispersal from healthy volunteers.

    PubMed

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

    2014-03-01

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

  7. [Staphylococcus aureus broncho-pulmonary infections].

    PubMed

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

    2013-12-01

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

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

    PubMed Central

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

    2010-01-01

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

  9. 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

  10. An in vivo reporter assay for sRNA-directed gene control in Gram-positive bacteria: identifying a novel sRNA target in Staphylococcus aureus

    PubMed Central

    Ivain, Lorraine; Bordeau, Valérie; Eyraud, Alex; Hallier, Marc; Dreano, Stéphane; Tattevin, Pierre

    2017-01-01

    Abstract Bacterial small regulatory RNAs (sRNAs) play a major role in the regulation of various cellular functions. Most sRNAs interact with mRNA targets via an antisense mechanism, modifying their translation and/or degradation. Despite considerable progresses in discovering sRNAs in Gram-positive bacteria, their functions, for the most part, are unknown. This is mainly due to difficulties in identifying their targets. To aid in the identification of sRNA targets in Gram-positive bacteria, we set up an in vivo method for fast analysis of sRNA-mediated post-transcriptional control at the 5΄ regions of target mRNAs. The technology is based on the co-expression of an sRNA and a 5΄ sequence of an mRNA target fused to a green fluorescent protein (GFP) reporter. The system was challenged on Staphylococcus aureus, an opportunistic Gram-positive pathogen. We analyzed several established sRNA–mRNA interactions, and in addition, we identified the ecb mRNA as a novel target for SprX2 sRNA. Using our in vivo system in combination with in vitro experiments, we demonstrated that SprX2 uses an antisense mechanism to prevent ecb mRNA translation initiation. Furthermore, we used our reporter assay to validate sRNA regulations in other Gram-positive organisms, Bacillus subtilis and Listeria monocytogenes. Overall, our method is broadly applicable to challenge the predicted sRNA–mRNA interactions in Gram-positive bacteria. PMID:28369640

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

    PubMed

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

    2010-08-01

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

  12. Novel insights into nickel import in Staphylococcus aureus: the positive role of free histidine and structural characterization of a new thiazolidine-type nickel chelator.

    PubMed

    Lebrette, H; Borezée-Durant, E; Martin, L; Richaud, P; Boeri Erba, E; Cavazza, C

    2015-04-01

    Staphylococcus aureus possesses two canonical ABC-importers dedicated to nickel acquisition: the NikABCDE and the CntABCDF systems, active under different growth conditions. This study reports on the extracytoplasmic nickel-binding components SaNikA and SaCntA. We showed by protein crystallography that SaNikA is able to bind either a Ni-(l-His)2 complex or a Ni-(l-His) (2-methyl-thiazolidine dicarboxylate) complex, depending on their availability in culture supernatants. Native mass spectrometry experiments on SaCntA revealed that it binds the Ni(ii) ion via a different histidine-dependent chelator but it cannot bind Ni-(l-His)2. In vitro experiments are consistent with in vivo nickel content measurements that showed that l-histidine has a high positive impact on nickel import via the Cnt system. These results suggest that although both systems may require free histidine, they use different strategies to import nickel.

  13. Metabolic sensor governing bacterial virulence in Staphylococcus aureus.

    PubMed

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

    2014-11-18

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

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

    PubMed

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

    2008-04-01

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

  15. 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.

  16. 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

  17. Evolution and virulence of Panton-Valentine leukocidin-positive ST30 methicillin-resistant Staphylococcus aureus in the past 30 years in Japan.

    PubMed

    Isobe, Hirokazu; Takano, Tomomi; Nishiyama, Akihito; Hung, Wei-Chun; Kuniyuki, Shuichi; Shibuya, Yasuhiro; Reva, Ivan; Yabe, Shizuka; Iwao, Yasuhisa; Higuchi, Wataru; Khokhlova, Olga E; Okubo, Takeshi; Yamamoto, Tatsuo

    2012-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) includes hospital-acquired MRSA (HAMRSA) and community-acquired MRSA (CA-MRSA). Panton-Valentine leukocidin (PVL)-positive multilocus sequence type 30 (ST30) MRSA is one of worldwide CA-MRSA, which has also persisted in Japan since the 1980s. However, unexpectedly, it was not the same ST30 clone throughout. Before 2000, it was HA-MRSA with spa43 and ψSa3sea (phage Sa3 carrying the sea gene) and only one PVL-positive MRSA in Japan; in the 1980s, ST30 MRSA accounted for 23.5% of HA-MRSA, showed multidrug resistance, had high MICs for oxacillin and imipenem, and caused decubitus and pneumonia in hospitalized patients. A dynamic clonal change (spa43/ψSa3sea→ spa19) occurred around 2000-2002. A rare spa43/ψSa3sea/SCCmecI-IE25923 genotype also emerged. After 2002, the prevalent spa19 clone was CA-MRSA; it accounted for only 0.3% (or less) of MRSA in hospitals but 7.6% of CA-MRSA. Since 2007, PVL-positive CA-MRSA with other ST types (such as ST8, ST22, and ST59) also emerged in Japan, albeit at a low frequency. ST30/spa19 CA-MRSA occasionally caused severe invasive infections and a novel ST1335/spa19 genotype emerged. These ST30/spa19 CA-MRSA and variants were identified by pulsed field gel electrophoresis. Further analysis revealed that PVL-positive ST30/spa19 CA-MRSA is a highlyvirulent, successful clone, having a potential of clonal expansion.

  18. 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

  19. Polymyxin-Coagulase-Deoxyribonuclease-Agar: a Selective Isolation Medium for Staphylococcus aureus1

    PubMed Central

    Orth, D. S.; Anderson, A. W.

    1970-01-01

    Fibrin halos developed around coagulase-positive Staphylococcus aureus colonies, and deoxyribonuclease production was detected by using a developing solution containing 1 mg of methyl green per ml. PMID:4098639

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

    PubMed

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

    2005-08-01

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

  1. [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.

  2. 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

  3. Methicillin-resistant Staphylococcus aureus in obstetrics.

    PubMed

    Sheffield, Jeanne S

    2013-02-01

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

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

    PubMed

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

    2016-07-01

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

  5. Emergence of methicillin resistance and Panton-Valentine leukocidin positivity in hospital- and community-acquired Staphylococcus aureus infections in Beira, Mozambique.

    PubMed

    van der Meeren, Birgitta T; Millard, Peter S; Scacchetti, Marco; Hermans, Mirjam H; Hilbink, Mirrian; Concelho, Timótio B; Ferro, Josefo J; Wever, Peter C

    2014-02-01

    The objective of this study was to investigate the antibiotic resistance patterns, including methicillin resistance, inducible macrolide-lincosamide-streptogramin B (MLSB ) resistance and Panton-Valentine leukocidin (PVL) toxin gene carriage among hospital-acquired Staphylococcus aureus (HA-SA) and community-acquired S. aureus (CA-SA), in Beira, Mozambique. In 2010-2011, two prospective surveillance studies were conducted on post-operative and burn wound infections at the Central Hospital of Beira and on skin and soft tissue abscesses at the São Lucas Health Centre. We cultured pus samples, identified suspected S. aureus isolates and performed antimicrobial susceptibility testing, including detection of MLSB resistance. Real-time polymerase chain reaction was used to detect mecA, Martineau and PVL genes. The prevalence of hospital-acquired methicillin-resistant S. aureus (HA-MRSA) infection among 53 inpatients was 15.1%; the prevalence of community-acquired methicillin-resistant S. aureus (CA-MRSA) infection among 100 outpatients was 1.0%. Inducible MLSB resistance was present in 41.7% and 10.7% of HA-SA and CA-SA isolates, respectively. PVL toxin gene was detected in 81.1% of methicillin-susceptible S. aureus (MSSA) compared with 11.1% of methicillin-resistant S. aureus. Our study shows, for the first time in Mozambique, the emergence of HA-MRSA. The prevalence of CA-MRSA was low, whereas the rate of PVL toxin gene carriage in MSSA was high. The high rate of inducible MLSB resistance indicates the importance of performing routine D-tests. Overall, our results show the need of strengthening laboratory facilities to provide microbiological data for both directed therapy and surveillance. © 2013 John Wiley & Sons Ltd.

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2015-09-01

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

  8. 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.

  9. 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

  10. Staphylococcus aureus Central Nervous System Infections in Children.

    PubMed

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

    2017-10-01

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

  11. Serological profiles in nursery piglets colonized with Staphylococcus aureus

    PubMed Central

    2013-01-01

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

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

    PubMed

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

    2007-01-01

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

  13. 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

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

    PubMed

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

    2007-03-01

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

  15. Staphopains Modulate Staphylococcus aureus Biofilm Integrity

    PubMed Central

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

    2013-01-01

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

  16. Factors associated with post-operative conversion to methicillin-resistant Staphylococcus aureus positivity or infection in initially MRSA-negative patients.

    PubMed

    Abi-Haidar, Youmna; Gupta, Kalpana; Strymish, Judith; Williams, Sandra A; Itani, Kamal M F

    2011-12-01

    Hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) is associated with morbid, invasive infections and has been implicated in nearly every type of nosocomial infection. Our aim was to identify the risk factors for patient conversion from MRSA negativity pre-operatively to MRSA positivity post-operatively. We retrospectively reviewed all patients at the Veterans Affairs-Boston Health Care System who underwent clean or clean-contaminated surgical procedures during the years 2008 and 2009 and had documented pre-operative nasal polymerase chain reaction (PCR) testing for MRSA. We abstracted post-operative MRSA microbiologic testing results, MRSA infections, surgical site infections (SSIs), surgical prophylaxis data, and SSI risk index, as calculated using the Veterans Affairs Surgical Quality Improvement Project (VASQIP) database variables. All patients who had a negative nasal MRSA PCR result in the 31-day pre-operative period and did not have any positive MRSA clinical swab or culture in the 1-year pre-operative period were defined as MRSA-negative. These patients were classified as converters to MRSA positivity if they had at least one documented positive nasal MRSA PCR swab, culture, nosocomial infection, or SSI within 31 days post-operatively. Among 4,238 eligible patients, 3,890 (92%) qualified as MRSA-negative pre-operatively. A total of 1,432 (37%) of these patients were assessed in the VASQIP database, of whom 34 (2%) converted to MRSA positivity post-operatively. On multivariable logistic regression analysis of the VASQIP sample, age (odds ratio [OR] 1.049; 95% confidence interval [CI] 1.016, 1.083), SSI risk index (OR 2.863; 95% CI 1.251-6.554), and vancomycin prophylaxis alone or in combination (OR 3.223; 95% CI 1.174-8.845) were significantly associated with conversion to MRSA positivity. In pre-operatively MRSA-negative patients, age, SSI risk index, and vancomycin prophylaxis were significant factors for conversion to MRSA positivity

  17. Pooled analysis of single-dose oritavancin in the treatment of acute bacterial skin and skin-structure infections caused by Gram-positive pathogens, including a large patient subset with methicillin-resistant Staphylococcus aureus.

    PubMed

    Corey, G Ralph; Arhin, Francis F; Wikler, Matthew A; Sahm, Daniel F; Kreiswirth, Barry N; Mediavilla, José R; Good, Samantha; Fiset, Claude; Jiang, Hai; Moeck, Greg; Kabler, Heidi; Green, Sinikka; O'Riordan, William

    2016-11-01

    Oritavancin is a lipoglycopeptide antibiotic with bactericidal activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). The phase 3 studies SOLO I and SOLO II demonstrated comparable efficacy and safety of a single dose of oritavancin compared with 7-10 days of twice-daily vancomycin in adults with acute bacterial skin and skin-structure infections (ABSSSIs). The present analysis assessed clinical responses by pathogen at 48-72 h and at study days 14-24 in SOLO patients within the pooled data set. Of the 1959 patients in the pooled SOLO studies, 1067 had at least one baseline Gram-positive pathogen and 405 had MRSA. Clinical response rates were similar for oritavancin- and vancomycin-treated patients by pathogen, including Staphylococcus aureus with or without the Panton-Valentine leukocidin (pvl) gene and from different clonal complexes, and were similar for pathogens within each treatment group. Oritavancin exhibited potent in vitro activity against all baseline pathogens, with MIC90 values (minimum inhibitory concentration required to inhibit 90% of the isolates) of 0.12 µg/mL for Staphylococcusaureus, 0.25 µg/mL for Streptococcus pyogenes and 0.06 µg/mL for Enterococcus faecalis. Whereas both oritavancin and vancomycin achieved similarly high rates of clinical response by pathogen, including methicillin-susceptible and -resistant Staphylococcus aureus, oritavancin provides a single-dose alternative to 7-10 days of twice-daily vancomycin to treat ABSSSIs.

  18. Survival of Staphylococcus aureus on fomites.

    PubMed

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

    2008-01-01

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

  19. 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

  20. 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

  1. 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

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

    PubMed Central

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

    2015-01-01

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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. NVC-422 inactivates Staphylococcus aureus toxins.

    PubMed

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

    2013-02-01

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

  8. Immunopathogenesis of Staphylococcus aureus pulmonary infection

    PubMed Central

    Parker, Dane; Prince, Alice

    2013-01-01

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

  9. 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.

  10. 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

  11. 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

  12. The effect of a cellulose dressing and topical vancomycin on methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive organisms in chronic wounds: a case series.

    PubMed

    Albaugh, Karen W; Biely, Scott A; Cavorsi, Joseph P

    2013-05-01

    High levels of persistent bacteria may contribute to wound chronicity and delayed healing. A prospective study was conducted to: 1) evaluate the effect of applying vancomycin topically on appropriately cultured chronic lower leg wounds, specifically methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive bacteria, and 2) evaluate its effect in combination with a cellulose dressing on healing. Twenty-three (23) outpatients (11 men, 12 women, average age 65 years [range 39-89 years]) with lower extremity wounds (15 venous ulcers, six chronic open wounds with a history of diabetes, and two chronic open trauma wounds) averaging 43.58 weeks' (range 5-121 weeks) duration and swab-cultured positive for MRSA or Gram-positive bacteria were provided 1 g vancomycin delivered by a cellulose dressing and changed every 72 hours. Patients served as their own control, and all wounds were debrided once a week. Wound surface area and bacterial and exudate levels were recorded weekly during the 3-week pretreatment period and compared to 3-week treatment period levels. Patients were followed until healed. Mean change in wound surface area was +14.5% (SD 71.91) per week before and -24.6% (SD 13.59) during the vancomycin treatment period (P = 0.014), average exudate levels decreased from 2.75 (range 1-4) to 1.81 (range 0-3) (P = 0.016), and the number of patients with positive wound cultures for MRSA or Gram-positive bacteria decreased from 23 to four after the 3-week study period. All wounds healed after an average of 8.18 weeks (SD 4.76, range 2-17 weeks). The results of this study suggest topical vancomycin applied using a dressing that retains moisture reduces wound bacterial load and may facilitate healing. Randomized, controlled clinical studies to evaluate the effectiveness and efficacy of this treatment modality and explore the relationship between wound culture results and healing are warranted.

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

    PubMed

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

    2016-10-01

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

  14. Macrolide-lincosamide-streptogramin resistance phenotypes and genotypes of coagulase-positive Staphylococcus aureus and coagulase-negative staphylococcal isolates from bovine mastitis.

    PubMed

    Li, Longping; Feng, Weiwei; Zhang, Zhiping; Xue, Huping; Zhao, Xin

    2015-07-25

    There are limited data available on macrolide-lincosamide-streptogramin (MLS) resistance of Staphylococcus aureus (S. aureus) and coagulase-negative staphylococci (CoNS) from bovine milk in China. To address this knowledge gap, MLS resistance was determined in 121 S. aureus and 97 CoNS isolates. Minimum inhibitory concentrations (MICs) of MLS antibiotics were determined by an agar dilution method, while differentiation of MLS phenotypes was performed by a double-disc diffusion test. MLS resistance genotypes were determined by PCR for corresponding resistance genes. Forty (33.1%) S. aureus and 65 (67.0%) CoNS were resistant to erythromycin, whereas all 218 isolates were susceptible to quinupristin/dalfopristin. Among 40 erythromycin-resistant (ER-R) S. aureus and 65 ER-R CoNS isolates, 38 S. aureus and 40 CoNS isolates exhibited the inducible MLS (iMLS) resistance phenotype and 2 S. aureus and 20 CoNS isolates expressed the constitutive MLS resistance (cMLS) phenotype. At the same time, 5 CoNS isolates exhibited resistance to erythromycin but susceptibility to clindamycin (the MS phenotype). An inactivating enzyme gene lnu(A), methylase genes erm(C) and erm(B), efflux genes msr(A)/msr(B), a phosphotransferase gene mph(C), an esterase gene ere(A) and the streptogramin resistance determinant vga(A) were detected individually or in combinations. Among them, genes lnu(A), erm(C) and mph(C) predominated. The ereA gene was detected for the first time in staphylococci of bovine milk origin. Resistance genes also existed in erythromycin-susceptible isolates. Our study demonstrated a high level of resistance to MLS antibiotics in staphylococci from bovine mastitic milk, especially with a high rate of the iMLS phenotype in S. aureus isolates. These data suggest that MLS antibiotics should be used judiciously to treat or prevent bovine mastitis caused by staphylococci.

  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. [Staphylococcus aureus in bulk milk samples].

    PubMed

    Benda, P; Vyletĕlová, M

    1995-07-01

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

  17. 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

  18. 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.

  19. AN EXPERIMENTAL STUDY OF OPSONIC IMMUNITY TO STAPHYLOCOCCUS AUREUS

    PubMed Central

    Meakins, J. C.

    1910-01-01

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

  20. The Bicomponent Pore-Forming Leucocidins of Staphylococcus aureus

    PubMed Central

    Alonzo, Francis

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2016-09-01

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

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

    PubMed

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

    2016-11-24

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

  5. 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

  6. Biochemical and Molecular Analysis of Staphylococcus aureus Clinical Isolates from Hospitalized Patients

    PubMed Central

    Karmakar, Amit; Dua, Parimal; Ghosh, Chandradipa

    2016-01-01

    Staphylococcus aureus is opportunistic human as well as animal pathogen that causes a variety of diseases. A total of 100 Staphylococcus aureus isolates were obtained from clinical samples derived from hospitalized patients. The presumptive Staphylococcus aureus clinical isolates were identified phenotypically by different biochemical tests. Molecular identification was done by PCR using species specific 16S rRNA primer pairs and finally 100 isolates were found to be positive as Staphylococcus aureus. Screened isolates were further analyzed by several microbiological diagnostics tests including gelatin hydrolysis, protease, and lipase tests. It was found that 78%, 81%, and 51% isolates were positive for gelatin hydrolysis, protease, and lipase activities, respectively. Antibiogram analysis of isolated Staphylococcus aureus strains with respect to different antimicrobial agents revealed resistance pattern ranging from 57 to 96%. Our study also shows 70% strains to be MRSA, 54.3% as VRSA, and 54.3% as both MRSA and VRSA. All the identified isolates were subjected to detection of mecA, nuc, and hlb genes and 70%, 84%, and 40% were found to harbour mecA, nuc, and hlb genes, respectively. The current investigation is highly important and informative for the high level multidrug resistant Staphylococcus aureus infections inclusive also of methicillin and vancomycin. PMID:27366185

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-11-01

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

  9. Antibacterial mechanism of fraxetin against Staphylococcus aureus.

    PubMed

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

    2014-11-01

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

  10. Binary IS Typing for Staphylococcus aureus

    PubMed Central

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

    2010-01-01

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

  11. 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

  12. 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

  13. 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

  14. Biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections.

    PubMed

    Hou, Wenbo; Sun, Xuguang; Wang, Zhiqun; Zhang, Yang

    2012-08-17

    To investigate the biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections. S. epidermidis strains, S. aureus strains, and P. aeruginosa strains were isolated from patients with ocular infections between 2009 and 2011. The biofilm-forming capacity of these bacteria was examined using Congo red agar (CRA) and microtiter plate assays. The biofilm-forming related genes, icaA, of S. epidermidis and S. aureus, and pslA, of P. aeruginosa, were detected using PCR. Additionally, the morphology of biofilms was observed using a scanning electron microscopy (SEM). Of the isolated S. epidermidis strains, 34.38% were CRA positive, 28.13% were adherence positive using the microtiter plate assay, and 40.63% carried the icaA gene. Of the isolated S. aureus strains, 55.56% were CRA positive, 51.90% were adherence positive, and 11.11% carried the icaA gene. None of the P. aeruginosa strains were phenotypic positive using CRA and microtiter plate assays, whereas 31.03% contained the pslA gene. There were significant differences between the three species when the biofilm-forming capacity of the strains was compared using the CRA method (P < 0.01) and the microtiter plate assay method (P < 0.01). Ophthalmic isolates of S. epidermidis and S. aureus could produce biofilms in vitro, whereas clinical strains of P. aeruginosa could not. The bacterial strains possess the genetic ability to produce biofilms, but that does not necessarily mean that biofilms will be produced. The knowledge of the process of bacterial adhesion suggests that a timely and appropriate intervention strategy be implemented in the early stages of biofilm-mediated infections.

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

    PubMed

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

    2016-11-21

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

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

    PubMed

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

    2015-11-01

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

  17. 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

  18. 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

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

    PubMed Central

    Morse, Stephen I.

    1962-01-01

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

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

    PubMed

    Alico, R K; Palenchar, C A

    1975-10-01

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

  1. 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

  2. Combination of ECMO and cytokine adsorption therapy for severe sepsis with cardiogenic shock and ARDS due to Panton-Valentine leukocidin-positive Staphylococcus aureus pneumonia and H1N1.

    PubMed

    Lees, N J; Rosenberg, Ajp; Hurtado-Doce, A I; Jones, J; Marczin, N; Zeriouh, M; Weymann, A; Sabashnikov, A; Simon, A R; Popov, A F

    2016-12-01

    Sepsis-induced cardiogenic shock in combination with severe acute respiratory failure represents a life-threatening combination that is often refractory to the conventional methods of treatment. We describe the case of a 33-year-old patient who developed acute cardiovascular collapse and ARDS secondary to superinfection of Panton-Valentine leukocidin-positive Staphylococcus aureus and H1N1 pneumonia who underwent successful combination therapy for severe sepsis-related cardiomyopathy and respiratory failure using extracorporeal membrane oxygenation and cytokine adsorption therapy.

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

    PubMed Central

    Sengupta, Mallika; Banerjee, Pritam; Guchhait, Partha

    2016-01-01

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

  4. Prevalence of multidrug-resistant, coagulase-positive Staphylococcus aureus in nasal carriage, food, wastewater and paper currency in Jalandhar city (north-western), an Indian state of Punjab.

    PubMed

    Kumar, Harsh; Palaha, Rajdeep; Kaur, Navreet; Ratnakar, Wankhede Swapnil; Sodi, Aakanksha; Kaur, Manmeet; Katiyar, Richa; Sharma, Mamta; Kaur, Charanpreet; Kumar, Virendra

    2015-01-01

    Development of multidrug-resistant pattern in the bacterial community is a major threat to the society. Staphylococcus aureus is perhaps the pathogen of the greatest concern because of its inherent virulence, its ability to cause a diverse array of life-threatening situations and capacity to adapt to different environmental conditions. The aims of this study is to investigate the multidrug-resistant pattern of the coagulase-positive S. aureus isolated from nasal carriage, food, paper currency and wastewater samples. We had also studied the multiple antibiotic resistance index and in vitro production of β-lactamase. The study had found out 130 coagulase-positive S. aureus strains isolated from total of 595 samples such as anterior nares of preschool children (195), hospital nurses (100), drivers (76), food (86), wastewater (3) and paper currency (135) (Indian rupee). The biotypes pattern were as follows; A > D > B > C> UT. Multiple antibiotic resistance (MAR) value clearly defines the multidrug-resistant pattern of the S. aureus among different sources. Statistical analysis (one-way ANOVA) of results obtained indicated that the difference in the antibiotic resistance observed in the 130 bacterial isolates against the 23 different antibiotics used in this study was statically significant (p < 0.01).

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

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

    PubMed

    Chang, Bao-Chi; Wang, Shyh-Jen

    2017-08-28

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

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

    PubMed

    Rashid, Rafi; Kline, Kimberly A

    2017-07-20

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

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

    PubMed

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

    2014-12-01

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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. Predictors of mortality in Staphylococcus aureus Bacteremia.

    PubMed

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

    2012-04-01

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

  18. 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.

  19. Molecular epidemiology of Staphylococcus aureus isolates at different sites in the milk producing dairy farms.

    PubMed

    Souza, Viviane; Nader Filho, Antonio; de Castro Melo, Poliana; Ferraudo, Guilherme Moraes; Antônio Sérgio, Ferraudo; de Oliveira Conde, Sandra; Fogaça Junior, Flavio Augusto

    2012-10-01

    The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples' collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines' insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents' transmission mechanism within the context of the farms investigated.

  20. Molecular epidemiology of Staphylococcus aureus isolates at different sites in the milk producing dairy farms

    PubMed Central

    Souza, Viviane; Nader Filho, Antonio; de Castro Melo, Poliana; Ferraudo, Guilherme Moraes; Antônio Sérgio, Ferraudo; de Oliveira Conde, Sandra; Fogaça Junior, Flavio Augusto

    2012-01-01

    The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples’ collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines’ insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents’ transmission mechanism within the context of the farms investigated. PMID:24031997

  1. 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.

  2. Staphylococcus aureus subsp. anaerobius strain ST1464 genome sequence

    PubMed Central

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

    2013-01-01

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

  3. Methicillin-Resistant Staphylococcus aureus Harboring mecC in Livestock in Spain

    PubMed Central

    Ariza-Miguel, Jaime; Fernández-Natal, Isabel

    2014-01-01

    We report for the first time mecC-positive methicillin-resistant Staphylococcus aureus (mecC-MRSA) in livestock in Spain. One isolate (sequence type 130) was found in milk samples among 601 S. aureus isolates obtained from 229 dairy sheep farms. This finding highlights the potential for zoonotic transmission of mecC-positive MRSA and the need for surveillance programs to monitor its presence and clonal evolution. PMID:25187631

  4. 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.

  5. 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

  6. 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.

  7. Molecular characterization of α-amylase from Staphylococcus aureus

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-08-01

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

  9. 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

  10. 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.

  11. 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

  12. 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

  13. Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites.

    PubMed

    Kurashige, E Jessica Ohashi; Oie, Shigeharu; Furukawa, H

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7-14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4cm×8cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0-255)colony-forming units (cfu)/100cm(2), respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0-1620)cfu/100cm(2), respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary.

  14. 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

  15. Methicillin-resistant Staphylococcus aureus in animals.

    PubMed

    Weese, J Scott

    2010-01-01

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

  16. Development and evaluation of hexaplex PCR for rapid detection of methicillin, cadmium/zinc and antiseptic-resistant staphylococci, with simultaneous identification of PVL-positive and -negative Staphylococcus aureus and coagulase negative staphylococci.

    PubMed

    Panda, Sasmita; Kar, Sarita; Choudhury, Ranginee; Sharma, Savitri; Singh, Durg V

    2014-03-01

    We developed a multiplex PCR to detect the presence of methicillin- (mecA), cadmium/zinc-(czrC) and antiseptic-resistant (qacA/B) staphylococci and to identify Panton-Valentine leukocidin (PVL)-positive and -negative Staphylococcus aureus and coagulase-negative staphylococci (CoNS) from infected and healthy eyes. The assay was validated on 177 staphylococci comprising of 55 each of S. aureus and CoNS isolated from infected eyes and five S. aureus and 62 CoNS isolated from healthy eyes and nine direct ocular samples. Nine direct ocular samples for in situ testing consisted of corneal scrapings (4), conjunctiva swabs (2) and others (3). Multiplex PCR result was correlated with genotype data obtained with single PCR and dot-blot assay. The control strains that were positive in multiplex PCR for 16S rRNA, nuc, mecA, pvl, czrC and qacA/B genes were also positive in the dot-blot assay. The specificity of amplified genes obtained with reference strains was further confirmed by DNA sequencing. The single step-hexaplex PCR method can be used for rapid detection of mecA, nuc, pvl, czrC and qacA/B genes in staphylococci with simultaneous identification of PVL-positive and -negative S. aureus and CoNS from a variety of ocular samples. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  17. 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.

  18. 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.

  19. Frequencies of resistance to Melaleuca alternifolia (tea tree) oil and rifampicin in Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis.

    PubMed

    Hammer, Katherine A; Carson, Christine F; Riley, Thomas V

    2008-08-01

    This study was conducted to determine the frequencies at which single-step mutants resistant to tea tree oil and rifampicin occurred amongst the Gram-positive organisms Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis. For tea tree oil, resistance frequencies were very low at <10(-9). Single-step mutants resistant to tea tree oil were undetectable at two times the minimum inhibitory concentration (MIC) for S. aureus RN4220 and derivative mutator strains or at 3 x MIC for the remaining S. aureus strains, including a clinical meticillin-resistant S. aureus isolate. Similarly, no mutants were recovered at 2x MIC for S. epidermidis or at 1x MIC for E. faecalis. Resistance frequencies determined in vitro for rifampicin (8 x MIC) ranged from 10(-7) to 10(-8) for all isolates, with the exception of the S. aureus mutator strains, which had slightly higher frequencies. These data suggest that Gram-positive organisms such as Staphylococcus and Enterococcus spp. have very low frequencies of resistance to tea tree oil.

  20. 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)

  1. 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.

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

    PubMed

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

    2014-07-01

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

  3. Staphylococcus aureus antigens and challenges in vaccine development.

    PubMed

    Middleton, John R

    2008-08-01

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

  4. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters.

    PubMed

    Plano, Lisa R W; Garza, Anna C; Shibata, Tomoyuki; Elmir, Samir M; Kish, Jonathan; Sinigalliano, Christopher D; Gidley, Maribeth L; Miller, Gary; Withum, Kelly; Fleming, Lora E; Solo-Gabriele, Helena M

    2011-01-06

    Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and toddlers shed their colonizing

  5. 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

  6. Staphylococcus aureus with Panton-Valentine toxin skin infection in a medical laboratory technician.

    PubMed

    Pougnet, Richard; Pougnet, Laurence

    2016-12-01

    This report exposes the case of a Staphylococcus aureus infection occurring in a microbiology laboratory technician. He was a 52 year-old man without medical history. He presented an abscess on the anterior aspect of the left forearm. Analysis showed that it was a Staphylococcus aureus secreting the Panton-Valentine toxin. The study of the workplace found the frequency of exposure. The study of workstation showed the link between the technician position and the infection. Indeed, this man touched an area where the biocleaning was hard to do. This is the first case of infection with PVL described for a laboratory technician.

  7. Characterization of Livestock-Associated Methicillin-Resistant Staphylococcus aureus CC398 and mecC-positive CC130 from Zoo Animals in the United Kingdom.

    PubMed

    Bortolami, Alessio; Verin, Ranieri; Chantrey, Julian; Corrò, Michela; Ashpole, Ian; Lopez, Javier; Timofte, Dorina

    2017-08-07

    Little is known about the characteristics and diseases associated with methicillin-resistant Staphylococcus aureus (MRSA) in nondomestic animals. Four presumptive MRSA isolates, obtained from clinical (n = 3) and surveillance specimens (n = 1) from dwarf (Helogale parvula) and yellow mongooses (Cynictis penicillata) from a United Kingdom zoo, were analyzed by PCR for detection of mecA and mecC-mediated methicillin resistance, and virulence genes. Isolates were genotyped by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) and spa sequence typing. Three isolates, obtained from the dwarf mongooses, carried mecA, tetK, and fexA resistance and virulence genes (icaA, icaD, and sec) and were typed to SCCmec IVa, spa type t899, and clonal complex (CC) 398. The fourth MRSA isolate, obtained from the femoral bone marrow of a yellow mongoose showing postmortem findings consistent with septicemia, carried mecC and was oxacillin/cefoxitin susceptible, when tested at 37°C but showed a characteristic MRSA susceptibility profile at 25°C ± 2°C. Furthermore, this isolate exhibited a different genetic background (SCCmecXI/t843/CC130) and had biofilm-associated genes (bap, icaA, and icaD) and tetK tetracycline resistance genes. This work describes the first isolation of livestock-associated MRSA CC398 from two zoo mongoose species where it was associated with both clinical disease and colonization, and the first isolation of mecC MRSA from a zoo species in the United Kingdom. Both reports highlight the potential for zoo species to act as reservoirs for these zoonotic agents.

  8. 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

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

    PubMed

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

    2015-07-01

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

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

    PubMed

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

    2010-01-01

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

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

    PubMed Central

    Fontana, C; Cellini, L; Dainelli, B

    1993-01-01

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

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

    PubMed

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

    1993-01-01

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

  13. Methicillin-resistant Staphylococcus aureus: Prevalence, incidence, risk factors, and effects on survival of patients in a specialist palliative care unit: A prospective observational study.

    PubMed

    Gleeson, Aoife; Larkin, Philip; Walsh, Cathal; O'Sullivan, Niamh

    2016-04-01

    Little is known about the impact of methicillin-resistant Staphylococcus aureus in palliative care settings. To date, the clinical impact of methicillin-resistant Staphylococcus aureus in palliative care is unknown. To determine prevalence and incidence of methicillin-resistant Staphylococcus aureus colonisation in a specialist palliative care setting, to identify risk factors for methicillin-resistant Staphylococcus aureus colonisation, to determine the eradication success rate and to determine the impact of methicillin-resistant Staphylococcus aureus on survival. Prospective cohort study. Data were collected for consecutive admissions to an inpatient palliative care service. Patients were screened for methicillin-resistant Staphylococcus aureus colonisation on admission and 1 week post admission. Methicillin-resistant Staphylococcus aureus eradication was attempted in methicillin-resistant Staphylococcus aureus positive patients. Data were collected from 609 admissions for 466 individual patients. Admission screening data were available in 95.5%. Prevalence of methicillin-resistant Staphylococcus aureus colonisation was 11.59% (54 patients). One week incidence of methicillin-resistant Staphylococcus aureus colonisation was 1.2%. Risk factors for methicillin-resistant Staphylococcus aureus colonisation were determined using Chi-Squared test and included high Waterlow score (p < 0.01), high palliative performance scale score (p < 0.01), methicillin-resistant Staphylococcus aureus status prior to admission (p < 0.01), admission from hospital (p < 0.05), presence of urinary catheter or percutaneous endoscopic gastrostomy tube (p < 0.05) and poor dietary intake (p < 0.05). Regression analysis did not identify independent risk factors. Methicillin-resistant Staphylococcus aureus was eradicated in 8.1% of admissions, while 46 patients commenced on the protocol (62.2%) died before completing it. Methicillin-resistant Staphylococcus aureus did

  14. Repurposing Salicylanilide Anthelmintic Drugs to Combat Drug Resistant Staphylococcus aureus

    PubMed Central

    Rajamuthiah, Rajmohan; Fuchs, Beth Burgwyn; Conery, Annie L.; Kim, Wooseong; Jayamani, Elamparithi; Kwon, Bumsup; Ausubel, Frederick M.; Mylonakis, Eleftherios

    2015-01-01

    Staphylococcus aureus is a Gram-positive bacterium that has become the leading cause of hospital acquired infections in the US. Repurposing Food and Drug Administration (FDA) approved drugs for antimicrobial therapy involves lower risks and costs compared to de novo development of novel antimicrobial agents. In this study, we examined the antimicrobial properties of two commercially available anthelmintic drugs. The FDA approved drug niclosamide and the veterinary drug oxyclozanide displayed strong in vivo and in vitro activity against methicillin resistant S. aureus (minimum inhibitory concentration (MIC): 0.125 and 0.5 μg/ml respectively; minimum effective concentration: ≤ 0.78 μg/ml for both drugs). The two drugs were also effective against another Gram-positive bacteria Enterococcus faecium (MIC 0.25 and 2 μg/ml respectively), but not against the Gram-negative species Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter aerogenes. The in vitro antimicrobial activity of niclosamide and oxyclozanide were determined against methicillin, vancomycin, linezolid or daptomycin resistant S. aureus clinical isolates, with MICs at 0.0625-0.5 and 0.125-2 μg/ml for niclosamide and oxyclozanide respectively. A time-kill study demonstrated that niclosamide is bacteriostatic, whereas oxyclozanide is bactericidal. Interestingly, oxyclozanide permeabilized the bacterial membrane but neither of the anthelmintic drugs exhibited demonstrable toxicity to sheep erythrocytes. Oxyclozanide was non-toxic to HepG2 human liver carcinoma cells within the range of its in vitro MICs but niclosamide displayed toxicity even at low concentrations. These data show that the salicylanilide anthelmintic drugs niclosamide and oxyclozanide are suitable candidates for mechanism of action studies and further clinical evaluation for treatment of staphylococcal infections. PMID:25897961

  15. 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.

  16. 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

  17. Low Efficacy of Antibiotics Against Staphylococcus aureus Airway Colonization in Ventilated Patients.

    PubMed

    Stulik, Lukas; Hudcova, Jana; Craven, Donald E; Nagy, Gabor; Nagy, Eszter

    2017-04-15

    Airway-colonization by Staphylococcus aureus predisposes to the development of ventilator-associated tracheobronchitis (VAT) and ventilator-associated pneumonia (VAP). Despite extensive antibiotic treatment of intensive care unit patients, limited data are available on the efficacy of antibiotics on bacterial airway colonization and/or prevention of infections. Therefore, microbiologic responses to antibiotic treatment were evaluated in ventilated patients. Results of semiquantitative analyses of S. aureus burden in serial endotracheal-aspirate (ETA) samples and VAT/VAP diagnosis were correlated to antibiotic treatment. Minimum inhibitory concentrations of relevant antibiotics using serially collected isolates were evaluated. Forty-eight mechanically ventilated patients who were S. aureus positive by ETA samples and treated with relevant antibiotics for at least 2 consecutive days were included in the study. Vancomycin failed to reduce methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) burden in the airways. Oxacillin was ineffective for MSSA colonization in approximately 30% of the patients, and responders were typically coadministered additional antibiotics. Despite antibiotic exposure, 15 of the 39 patients (approximately 38%) colonized only by S. aureus and treated with appropriate antibiotic for at least 2 days still progressed to VAP. Importantly, no change in antibiotic susceptibility of S. aureus isolates was observed during treatment. Staphylococcus aureus colonization levels inversely correlated with the presence of normal respiratory flora. Antibiotic treatment is ineffective in reducing S. aureus colonization in the lower airways and preventing VAT or VAP. Staphylococcus aureus is in competition for colonization with the normal respiratory flora. To improve patient outcomes, alternatives to antibiotics are urgently needed.

  18. 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

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

    PubMed

    Krishna, Sheila; Miller, Lloyd S

    2012-02-01

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

  20. Gastrointestinal Dissemination and Transmission of Staphylococcus aureus following Bacteremia

    PubMed Central

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

    2014-01-01

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

  1. Impact of Staphylococcus aureus on Pathogenesis in Polymicrobial Infections

    PubMed Central

    Nair, Nisha; Biswas, Raja; Götz, Friedrich

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  5. Cooperation, Quorum Sensing, and Evolution of Virulence in Staphylococcus aureus

    PubMed Central

    Pollitt, Eric J. G.; West, Stuart A.; Crusz, Shanika A.; Burton-Chellew, Maxwell N.

    2014-01-01

    The virulence and fitness in vivo of the major human pathogen Staphylococcus aureus are associated with a cell-to-cell signaling mechanism known as quorum sensing (QS). QS coordinates the production of virulence factors via the production and sensing of autoinducing peptide (AIP) signal molecules by the agr locus. Here we show, in a wax moth larva virulence model, that (i) QS in S. aureus is a cooperative social trait that provides a benefit to the local population of cells, (ii) agr mutants, which do not produce or respond to QS signal, are able to exploit the benefits provided by the QS of others (“cheat”), allowing them to increase in frequency when in mixed populations with cooperators, (iii) these social interactions between cells determine virulence, with the host mortality rate being negatively correlated to the percentage of agr mutants (“cheats”) in a population, and (iv) a higher within-host relatedness (lower strain diversity) selects for QS and hence higher virulence. Our results provide an explanation for why agr mutants show reduced virulence in animal models but can be isolated from infections of humans. More generally, by providing the first evidence that QS is a cooperative social behavior in a Gram-positive bacterium, our results suggest convergent, and potentially widespread, evolution for signaling to coordinate cooperation in bacteria. PMID:24343650

  6. 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.

  7. Cooperation, quorum sensing, and evolution of virulence in Staphylococcus aureus.

    PubMed

    Pollitt, Eric J G; West, Stuart A; Crusz, Shanika A; Burton-Chellew, Maxwell N; Diggle, Stephen P

    2014-03-01

    The virulence and fitness in vivo of the major human pathogen Staphylococcus aureus are associated with a cell-to-cell signaling mechanism known as quorum sensing (QS). QS coordinates the production of virulence factors via the production and sensing of autoinducing peptide (AIP) signal molecules by the agr locus. Here we show, in a wax moth larva virulence model, that (i) QS in S. aureus is a cooperative social trait that provides a benefit to the local population of cells, (ii) agr mutants, which do not produce or respond to QS signal, are able to exploit the benefits provided by the QS of others ("cheat"), allowing them to increase in frequency when in mixed populations with cooperators, (iii) these social interactions between cells determine virulence, with the host mortality rate being negatively correlated to the percentage of agr mutants ("cheats") in a population, and (iv) a higher within-host relatedness (lower strain diversity) selects for QS and hence higher virulence. Our results provide an explanation for why agr mutants show reduced virulence in animal models but can be isolated from infections of humans. More generally, by providing the first evidence that QS is a cooperative social behavior in a Gram-positive bacterium, our results suggest convergent, and potentially widespread, evolution for signaling to coordinate cooperation in bacteria.

  8. 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.

  9. Emergence of Panton-Valentine leukocidin-positive ST59 methicillin-susceptible Staphylococcus aureus with high cytolytic peptide expression in association with community-acquired pediatric osteomyelitis complicated by pulmonary embolism.

    PubMed

    Sawanobori, Emi; Hung, Wei-Chun; Takano, Tomomi; Hachuda, Koji; Horiuchi, Tadahiro; Higuchi, Wataru; Hung, Wei-Wen; Iwao, Yasuhisa; Nishiyama, Akihito; Reva, Ivan; Reva, Galina; Teng, Lee-Jene; Yamamoto, Tatsuo

    2015-10-01

    A 15-year-old boy, who had had a furuncle on his femur, developed femoral pyomyositis and osteomyelitis complicated by septic pulmonary embolism. Panton-Valentine leukocidin-positive (PVL(+)) ST59 methicillin-susceptible Staphylococcus aureus (MSSA) was isolated from pus and blood. Chemotherapy was started with cefazolin, followed by combination therapy with meropenem/vancomycin with surgery. The MSSA (strain KS1) was positive for increased levels of cytolytic peptide (psmα and hld) and staphylococcal enterotoxin B (SEB), and manifested IS1216V-mediated multidrug resistance (to erythromycin, clindamycin, kanamycin, streptomycin, and chloramphenicol), similar to a genome-analyzed reference strain (PM1) of ST59/SCCmecV(5C2&5) community-associated methicillin-resistant S. aureus (Taiwan CA-MRSA), but unlike another reference strain (M013) of Taiwan CA-MRSA in terms of resistance. The data suggest that CA-MSSA KS1, characterized by PVL, increased levels of cytolytic peptide, SEB, and multidrug resistance, is a possible ancestral strain of Taiwan CA-MRSA and causes the unique association of osteomyelitis and septic pulmonary embolism, requiring complicated management. Copyright © 2014. Published by Elsevier B.V.

  10. 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

  11. 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…

  12. 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.

  13. 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

  14. USA300 Methicillin-resistant Staphylococcus aureus in Cuba

    PubMed Central

    2012-01-01

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

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

    PubMed

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

    2009-06-01

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

  16. Microstructures as IR-sensors with Staphylococcus aureus bacteria

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

  17. 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.

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

    USDA-ARS?s Scientific Manuscript database

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

  19. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  20. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  1. 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…

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  4. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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

  5. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  6. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  7. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  8. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  9. [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.

  10. The Staphylococcus aureus FASII bypass escape route from FASII inhibitors.

    PubMed

    Morvan, Claire; Halpern, David; Kénanian, Gérald; Pathania, Amit; Anba-Mondoloni, Jamila; Lamberet, Gilles; Gruss, Alexandra; Gloux, Karine

    2017-10-01

    Antimicrobials targeting the fatty acid synthesis (FASII) pathway are being developed as alternative treatments for bacterial infections. Emergence of resistance to FASII inhibitors was mainly considered as a consequence of mutations in the FASII target genes. However, an alternative and efficient anti-FASII resistance strategy, called here FASII bypass, was uncovered. Bacteria that bypass FASII incorporate exogenous fatty acids in membrane lipids, and thus dispense with the need for FASII. This strategy is used by numerous Gram-positive low GC % bacteria, including streptococci, enterococci, and staphylococci. Some bacteria repress FASII genes once fatty acids are available, and "constitutively" shift to FASII bypass. Others, such as the major pathogen Staphylococcus aureus, can undergo high frequency mutations that favor FASII bypass. This capacity is particularly relevant during infection, as the host supplies the fatty acids needed for bacteria to bypass FASII and thus become resistant to FASII inhibitors. Screenings for anti-FASII resistance in the presence of exogenous fatty acids confirmed that FASII bypass confers anti-FASII resistance among clinical and veterinary isolates. Polymorphisms in S. aureus FASII initiation enzymes favor FASII bypass, possibly by increasing availability of acyl-carrier protein, a required intermediate. Here we review FASII bypass and consequences in light of proposed uses of anti-FASII to treat infections, with a focus on FASII bypass in S. aureus. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Coagulase-Positive Staphylococcus: Prevalence and Antimicrobial Resistance.

    PubMed

    Beça, Nuno; Bessa, Lucinda Janete; Mendes, Ângelo; Santos, Joana; Leite-Martins, Liliana; Matos, Augusto J F; da Costa, Paulo Martins

    2015-01-01

    Staphylococcus pseudintermedius is the most prevalent coagulase-positive Staphylococcus inhabitant of the skin and mucosa of dogs and cats, causing skin and soft tissue infections in these animals. In this study, coagulase-positive Staphylococcus species were isolated from companion animals, veterinary professionals, and objects from a clinical veterinary environment by using two particular culture media, Baird-Parker RPF agar and CHROMagar Staph aureus. Different morphology features of colonies on the media allowed the identification of the species, which was confirmed by performing a multiplex polymerase chain reaction (PCR). Among 23 animals, 15 (65.2%) harbored coagulase-positive Staphylococcus, being 12 Staphylococcus pseudintermedius carriers. Four out of 12 were methicillin-resistant S. pseudintermedius (MRSP). All veterinary professionals had coagulase-positive Staphylococcus (CoPS) species on their hands and two out of nine objects sampled harbored MRSP. The antimicrobial-resistance pattern was achieved for all isolates, revealing the presence of many multidrug-resistant CoPS, particularly S. pseudintermedius . The combined analysis of the antimicrobial-resistance patterns shown by the isolates led to the hypothesis that there is a possible crosscontamination and dissemination of S. aureus and S. pseudintermedius species between the three types of carriers sampled in this study that could facilitate the spread of the methicillin-resistance phenotype.

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

    PubMed

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

    2006-04-15

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

  13. 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.

  14. 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

  15. Characterization of PVL/ACME-positive methicillin-resistant Staphylococcus aureus (genotypes ST8-MRSA-IV and ST5-MRSA-II) isolated from a university hospital in Japan.

    PubMed

    Kawaguchiya, Mitsuyo; Urushibara, Noriko; Yamamoto, Dai; Yamashita, Toshiharu; Shinagawa, Masaaki; Watanabe, Naoki; Kobayashi, Nobumichi

    2013-02-01

    The ST8 methicillin-resistant Staphylococcus aureus (MRSA) with Staphylococcal cassette chromosome mec (SCCmec) type IVa, known as USA300, is a prevalent community-acquired MRSA (CA-MRSA) clone in the United States and has been spreading worldwide. The USA300 characteristically harbors Panton-Valentine Leukocidin (PVL) genes and the arginine catabolic mobile element (ACME, type I). Prevalence and molecular characteristics of PVL(+) and/or ACME(+) S. aureus were investigated in a university hospital located in northern Japan, for 1,366 S. aureus isolates, including 601 MRSA strains derived from clinical specimens collected from 2008 to 2010. The PVL gene was identified in three MRSA strains with SCCmec IV, which belonged to ST8, spa type t008, coagulase type III, and agr type I. Two PVL-positive MRSA strains had also type I ACME, and were isolated from skin abscess of outpatients who have not travelled abroad recently. One of these PVL(+)/ACME(+) strains carried tet(K), msrA, and aph(3')-IIIa, showing resistance to kanamycin, tetracycline, erythromycin, and ciprofloxacin, suggesting acquisition of more resistance than ST8 CA-MRSA reported in Japan previously. In contrast, another PVL(+)/ACME(+) strain and a PVL(+)/ACME(-) strain were susceptible to more antimicrobials and had less virulence factors than PVL(-)/ACME(+) MRSA strains. Besides the two PVL(+) MRSA strains, ACME (type-ΔII) was identified into seven MRSA strains with SCCmec II belonging to ST5, one of the three spa types (t002, t067, and t071), coagulase type II, and agr type II. These PVL(-)/ACME(+) MRSA strains showed multiple drug resistance and harbored various toxin genes as observed for ST5 PVL(-)/ACME(-) MRSA-II. The present study suggested the spread of ST8-MRSA-IV in northern Japan, and a potential significance of ACME-positive ST5-MRSA-II as an emerging MRSA clone in a hospital.

  16. Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis.

    PubMed

    Ciftci, Alper; Findik, Arzu; Onuk, Ertan Emek; Savasan, Serap

    2009-04-01

    This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7%) were positive for mecA gene. Although 22 of 59 (37.2%) S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains.

  17. Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis

    PubMed Central

    Ciftci, Alper; Findik, Arzu; Onuk, Ertan Emek; Savasan, Serap

    2009-01-01

    This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7%) were positive for mecA gene. Although 22 of 59 (37.2%) S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains. PMID:24031354

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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

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

    PubMed

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

    2017-02-01

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

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

    PubMed

    Goldmann, Oliver; Medina, Eva

    2017-09-15

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

  5. 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.

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

    PubMed

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

    2017-10-06

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

  7. 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

  8. Livestock-associated Staphylococcus aureus on Polish pig farms.

    PubMed

    Mroczkowska, Aneta; Żmudzki, Jacek; Marszałek, Natalia; Orczykowska-Kotyna, Monika; Komorowska, Iga; Nowak, Agnieszka; Grzesiak, Anna; Czyżewska-Dors, Ewelina; Dors, Arkadiusz; Pejsak, Zygmunt; Hryniewicz, Waleria; Wyszomirski, Tomasz; Empel, Joanna

    2017-01-01

    Livestock-associated Staphylococcus aureus (LA-SA) draws increasing attention due to its particular ability to colonize farm animals and be transmitted to people, which in turn leads to its spread in the environment. The aim of the study was to determine the dissemination of LA-SA on pig farms selected throughout Poland, characterize the population structure of identified S. aureus, and assess the prevalence of LA-SA carriage amongst farmers and veterinarians being in contact with pigs. The study was conducted on 123 pig farms (89 farrow-to-finish and 34 nucleus herds), located in 15 out of 16 provinces of Poland. Human and pig nasal swabs, as well as dust samples were analyzed. S. aureus was detected on 79 (64.2%) farms from 14 provinces. Amongst these farms LA-SA-positive farms dominated (71/79, 89.9%, 95% CI [81.0%, 95.5%]). The prevalence of LA-MRSA-positive farms was lower than LA-MSSA-positive (36.6% of LA-SA-positive farms, 95% CI [25.5%, 48.9%] vs. 74.6%, 95% CI [62.9%, 84.2%]). In total, 190 S. aureus isolates were identified: 72 (38%) MRSA and 118 (62%) methicillin-susceptible S. aureus (MSSA), of which 174 (92%) isolates were classified to three livestock-associated lineages: CC398 (73%), CC9 (13%), and CC30/ST433 (6%). All CC398 isolates belonged to the animal clade. Four LA-MRSA clones were detected: ST433-IVa(2B) clone (n = 8, 11%), described to the best of our knowledge for the first time, and three ST398 clones (n = 64, 89%) with the most prevalent being ST398-V(5C2&5)c, followed by ST398-V(5C2), and ST398-IVa(2B). Nasal carriage of LA-SA by pig farmers was estimated at 13.2% (38/283), CC398 carriage at 12.7% (36/283) and ST398-MRSA carriage at 3.2% (9/283), whereas by veterinarians at 21.1% (8/38), 18.4% (7/38) and 10.5% (4/38), respectively. The prevalence of LA-MRSA-positive pig farms in Poland has increased considerably since 2008, when the first MRSA EU baseline survey was conducted in Europe. On Polish pig farms CC398 of the animal clade

  9. Staphylococcus aureus Nasal Colonization Differs among Pig Lineages and Is Associated with the Presence of Other Staphylococcal Species.

    PubMed

    Verstappen, Koen M; Willems, Eveline; Fluit, Ad C; Duim, Birgitta; Martens, Marc; Wagenaar, Jaap A

    2017-01-01

    Staphylococcus aureus is a common colonizer in pigs, with methicillin-resistant S. aureus (MRSA) in particular being a potential health risk to humans. To reduce the exposure to humans, the colonization in pigs should be reduced. The aim of this study was to quantitatively compare the susceptibility of pig lineages for S. aureus colonization, and if the absence of S. aureus could be associated with the presence or absence of other staphylococcal species. Nasal samples (n = 129) were obtained from seven different pig lineages in the Netherlands, France, and Germany. S. aureus and other staphylococci were enumerated from these samples by real-time (RT)-PCR and culture. Associations were explored between the presence of S. aureus and other staphylococci. S. aureus was detected by RT-PCR on all farms and in samples from pigs of all lineages. Twenty-five percent of the pigs from lineage F (from two farms) were colonized with S. aureus, while in all other lineages it was more than 50% (p < 0.01). Moreover, in S. aureus-positive samples from pigs of lineage F smaller amounts of S. aureus were found than in other lineages. Staphylococcus sciuri, Staphylococcus cohnii, and Staphylococcus saprophyticus were usually not found in combination with S. aureus in these samples. (i) pigs from different genetic lineages have different susceptibilities for colonization with S. aureus. These pigs might contain a genetic factor influencing nasal colonization. (ii) Colonization of S. aureus is also associated with the absence of S. sciuri, S. cohnii, or S. saprophyticus. (iii) The farm environment seems to influence the presence of S. aureus in pigs.

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

    PubMed

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

    2015-10-01

    Staphylococcus aureus is a significant pathogen that can colonize the nares of different animals, causing a wide range of infections in various hosts. 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. 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. 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. 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.

  11. 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

  12. Population structure and antimicrobial profile of Staphylococcus aureus strains associated with bovine mastitis in China.

    PubMed

    Zhang, Lili; Li, Yuchen; Bao, Hongduo; Wei, Ruicheng; Zhou, Yan; Zhang, Hui; Wang, Ran

    2016-08-01

    Staphylococcus aureus is a significant bacterial pathogen associated with bovine mastitis. The aim of the present study was to investigate and characterize of S. aureus strains isolated from the milk of cows suffering from mastitis in the mid-east of China. Among the 200 milk samples analyzed, 58 were positive for S. aureus, of these isolates, 11 isolates were methicillin-resistant Staphylococcus aureus (MRSA). All of the 58 S. aureus strains were classified in agr group I, while seven different sequence type (ST) patterns were identified and among them the most common was ST630 followed by ST188. All of the S. aureus isolates belonging to ST630 were resistant to more than four antimicrobials, and 22.2% of isolates belonging to ST188 were resistant to eight antimicrobials. Interestingly, while strong biofilm producers demonstrated higher resistance to multiple antimicrobials, they exhibited lower intracellular survival rates. The results of this study illustrated the distribution, antimicrobial susceptibility profiles, genotype, and the ability of biofilm production and mammary epithelial cells invasion of these S. aureus isolates. This study can provide the basis for the development of a disease prevention program in dairy farms to reduce the potential risk in both animal and human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Accuracy of tracheal aspirate gram stain in predicting Staphylococcus aureus infection in ventilator-associated pneumonia.

    PubMed

    Seligman, Renato; Seligman, Beatriz Graeff Santos; Konkewicz, Loriane; Dos Santos, Rodrigo Pires

    2015-01-01

    The Gram stain can be used to direct initial empiric antimicrobial therapy when complete culture is not available. This rapid test could prevent the initiation of inappropriate therapy and adverse outcomes. However, several studies have attempted to determine the value of the Gram stain in the diagnosis and therapy of bacterial infection in different populations of patients with ventilator-associated pneumonia (VAP) with conflicting results. The objective of this study is to evaluate the accuracy of the Gram stain in predicting the existence of Staphylococcus aureus infections from cultures of patients suspected of having VAP. This prospective single-center open cohort study enrolled 399 patients from December 2005 to December 2010. Patients suspected of having VAP by ATS IDSA criteria were included. Respiratory secretion samples were collected by tracheal aspirate (TA) for standard bacterioscopic analysis by Gram stain and culture. Respiratory secretion samples collected by tracheal aspirates of 392 patients were analyzed by Gram stain and culture. When Gram-positive cocci were arranged in clusters, the sensitivity was 68.4%, specificity 97.8%, positive predictive value 88.1% and negative predictive value 92.8% for predicting the presence of Staphylococcus aureus in culture (p < 0.001). A tracheal aspirate Gram stain can be used to rule out the presence of Staphylococcus aureus in patients with a clinical diagnosis of VAP with a 92.8% Negative Predictive Value. Therefore, 7.2% of patients with Staphylococcus aureus would not be protected by an empiric treatment that limits antimicrobial coverage to Staphylococcus aureus only when Gram positive cocci in clusters are identified.

  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. Intracellular staphylococcus aureus: Live-in and let die

    PubMed Central

    Fraunholz, Martin; Sinha, Bhanu

    2012-01-01

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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. [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.

  1. 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.

  2. 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

  3. [Rapid detection of oxacillin and erythromycin resistance genes in Staphylococcus aureus using multiplex PCR].

    PubMed

    Huang, Ge; Zhou, Xiao-hong; Jiang, Wen-ling; Rong, Ka-bin; Zhao, Yin

    2008-04-01

    To establish a rapid multiplex PCR (MPCR) detection system of oxacillin and erythromycin resistance genes in Staphylococcus aureus (S. aureus) and evaluate the genotype distribution of the genes associated to mecA, ermA and ermC resistance in Guangzhou. The S. aureus strains were identified and susceptibility tests were performed using VITEK-60 or PHOENIX-100 system. The inducible resistance to clindamycin of strains with of erythromycin resistance was conducted using D-test, and the MPCR system of for detecting the antibiotic resistance genes was optimized. The MPCR assay for detecting the resistance genes was constructed successfully. According to the results of MPCR, the positivity rates for mecA, ermA and ermC genes among the 124 strains of S. aureus isolated from clinical samples were 56.5%, 50% and 33.9%, respectively. Good correlation was observed between the antibiotic resistance phenotypes and the S. aureus genotypes. mecA were detected in all the methicillin-resistant S. aureus strains, and ermA and/or ermC in 97.7% of the S. aureus strains with erythromycin resistance. This MPCR system allows rapid and reliable analysis of antibiotic resistance genotypes of S. aureus isolated from clinical samples. mecA, ermA, and ermC genes are among the predominant genetic determinants for the resistance to oxacillin and erythromycin in S. aureus isolates in Guangzhou.

  4. PLASMA COAGULATION BY ORGANISMS OTHER THAN STAPHYLOCOCCUS AUREUS.

    PubMed

    BAYLISS, B G; HALL, E R

    1965-01-01

    Bayliss, Berenice G. (Washington State University, Pullman), and Elizabeth R. Hall. Plasma coagulation by organisms other than Staphylococcus aureus. J. Bacteriol. 89:101-105. 1965.-Approximately 200 organisms were investigated for their ability to clot human and rabbit plasma. Various anticoagulants were used in preparing the plasma: acid-citrate-dextrose, ethylenediaminetetraacetate, balanced oxalate, potassium and sodium oxalates, and heparin. Twelve organisms were found which coagulated citrated plasma in less than 8 hr: four strains of Streptococcus faecalis; two strains of S. faecalis var. zymogenes; three strains of S. faecalis var. liquefaciens; and one strain each of S. pyogenes, Escherichia coli, and Serratia marcescens. Six strains of coagulase-positive Staphylococcus were selected for use as controls. Experiments were performed to determine the mechanism by which these microorganisms coagulated citrated plasma. As this was the only plasma clotted, it was presumed that the citrate was utilized by the microorganisms, thereby releasing the calcium which was then made available so that normal physiological clotting could occur. To test this hypothesis, a chromatographic method was employed to determine the presence or absence of citrate. Coagulation tests, by use of increasing amounts of citrate, showed a linear relationship between the amount of citrate in the plasma and the coagulation time. It was demonstrated that the organisms must be actively metabolizing to clot citrated plasma. Proof for this was obtained by using a cell-free filtrate, to which thimerosal had been added to inhibit growth, instead of whole cultures for the coagulation test. Only the coagulase-positive staphylococci coagulated the citrated plasma under these conditions. From the results obtained, it was concluded that plasma coagulation by these organisms was by citrate utilization.

  5. 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.

  6. Prevalence of Staphylococcus aureus toxins and nasal carriage in furuncles and impetigo.

    PubMed

    Durupt, F; Mayor, L; Bes, M; Reverdy, M-E; Vandenesch, F; Thomas, L; Etienne, J

    2007-12-01

    The precise role of Staphylococcus aureus toxins and nasal carriage in common skin infections remains unclear. To seek correlations between toxin expression, S. aureus nasal carriage and clinical manifestations in patients with community-acquired furuncles and impetigo. From November 2004 to August 2005, we studied clinical data and bacteriological samples prospectively collected from 121 patients presenting with furuncles or impetigo. Sixty-four patients (31 with furuncles and 33 with impetigo) had S. aureus-positive skin culture. Panton-Valentine leukocidin (PVL) genes were present in 13 of 31 (42%) isolates from furuncles and were associated with epidemic furunculosis. Exfoliative toxin genes were present in 10 of 10 (100%) and 12 of 21 (57%) bullous and nonbullous impetigo isolates, respectively. Nasal carriage of S. aureus was found in 58% of patients overall. It was strongly associated with chronic furunculosis but not with simple furuncles (88% vs. 29%, P < 0.007). Skin and nose isolates from a given patient always had identical characteristics. Methicillin-resistant S. aureus accounted for four of 64 (6%) positive skin cultures. PVL is not involved in all types of furuncles but is associated with epidemic furunculosis. Both bullous and nonbullous forms of impetigo are associated with exfoliative toxins. Staphylococcus aureus nasal carriage is associated with the chronicity of furuncles.

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

    PubMed

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

    2014-11-01

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

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

    PubMed

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

    2011-11-01

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

  9. 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.

  10. 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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  13. Panton-Valentine leukocidin (PVL)-positive health care-associated methicillin-resistant Staphylococcus aureus isolates are associated with skin and soft tissue infections and colonized mainly by infective PVL-encoding bacteriophages.

    PubMed

    Hu, Qiwen; Cheng, Hang; Yuan, Wenchang; Zeng, Fangyin; Shang, Weilong; Tang, Dahai; Xue, Wencheng; Fu, Jianfeng; Zhou, Renjie; Zhu, Junmin; Yang, Jie; Hu, Zhen; Yuan, Jizhen; Zhang, Xia; Rao, Qing; Li, Shu; Chen, Zhijin; Hu, Xiaomei; Wu, Xingan; Rao, Xiancai

    2015-01-01

    The emergence of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) is a public health concern worldwide. PVL is associated with community-associated MRSA and is linked to skin and soft tissue infections (SSTIs). However, PVL genes have also been detected in health care-associated (HA) MRSA isolates. The diseases associated with PVL-positive HA-MRSA isolates and the distributions of PVL-encoding bacteriophages in HA-MRSA have not been determined. In this study, a total of 259 HA-MRSA strains isolated between 2009 and 2012 in China from inpatients with SSTIs, pneumonia, and bacteremia were selected for molecular typing, including staphylococcal cassette chromosome mec typing, multilocus sequence typing, and staphylococcal protein A gene typing. The PVL genes and PVL bacteriophages in the MRSA isolates were characterized by PCR. Among the tested MRSA isolates, 28.6% (74/259) were PVL positive. The high prevalence of PVL-carrying HA-MRSA was observed to be associated with SSTIs but not with pneumonia or bacteremia. The PVL-positive HA-MRSA isolates were colonized mainly by infective PVL phages, namely, Φ7247PVL, ΦSLT, and ΦSa2958. The distribution of PVL-carrying bacteriophages differed geographically. Our study highlights the potential risk of the emergence of multidrug-resistant HA-MRSA strains with increased virulence. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Panton-Valentine Leukocidin (PVL)-Positive Health Care-Associated Methicillin-Resistant Staphylococcus aureus Isolates Are Associated with Skin and Soft Tissue Infections and Colonized Mainly by Infective PVL-Encoding Bacteriophages

    PubMed Central

    Hu, Qiwen; Cheng, Hang; Yuan, Wenchang; Zeng, Fangyin; Shang, Weilong; Tang, Dahai; Xue, Wencheng; Fu, Jianfeng; Zhou, Renjie; Zhu, Junmin; Yang, Jie; Hu, Zhen; Yuan, Jizhen; Zhang, Xia; Rao, Qing; Li, Shu; Chen, Zhijin; Hu, Xiaomei; Wu, Xingan

    2014-01-01

    The emergence of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) is a public health concern worldwide. PVL is associated with community-associated MRSA and is linked to skin and soft tissue infections (SSTIs). However, PVL genes have also been detected in health care-associated (HA) MRSA isolates. The diseases associated with PVL-positive HA-MRSA isolates and the distributions of PVL-encoding bacteriophages in HA-MRSA have not been determined. In this study, a total of 259 HA-MRSA strains isolated between 2009 and 2012 in China from inpatients with SSTIs, pneumonia, and bacteremia were selected for molecular typing, including staphylococcal cassette chromosome mec typing, multilocus sequence typing, and staphylococcal protein A gene typing. The PVL genes and PVL bacteriophages in the MRSA isolates were characterized by PCR. Among the tested MRSA isolates, 28.6% (74/259) were PVL positive. The high prevalence of PVL-carrying HA-MRSA was observed to be associated with SSTIs but not with pneumonia or bacteremia. The PVL-positive HA-MRSA isolates were colonized mainly by infective PVL phages, namely, Φ7247PVL, ΦSLT, and ΦSa2958. The distribution of PVL-carrying bacteriophages differed geographically. Our study highlights the potential risk of the emergence of multidrug-resistant HA-MRSA strains with increased virulence. PMID:25339405

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

    PubMed Central

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

    2011-01-01

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

  16. 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.

  17. RNA-Seq Reveals Differential Gene Expression in Staphylococcus aureus with Single-Nucleotide Resolution

    PubMed Central

    Osmundson, Joseph; Dewell, Scott; Darst, Seth A.

    2013-01-01

    Staphylococcus aureus is a gram-positive cocci and an important human commensal bacteria and pathogen. S. aureus infections are increasingly difficult to treat because of the emergence of highly resistant MRSA (methicillin-resistant S. aureus) strains. Here we present a method to study differential gene expression in S. aureus using high-throughput RNA-sequencing (RNA-seq). We used RNA-seq to examine gene expression in S. aureus RN4220 cells containing an exogenously expressed transcription factor and between two S. aureus strains (RN4220 and NCTC8325-4). We investigated the sequence and gene expression differences between RN4220 and NCTC8325-4 and used the RNA-seq data to identify S. aureus promoters suitable for in vitro analysis. We used RNA-seq to describe, on a genome wide scale, genes positively and negatively regulated by the phage encoded transcription factor gp67. RNA-seq offers the ability to study differential gene expression with single-nucleotide resolution, and is a considerable improvement over the predominant genome-wide transcriptome technologies used in S. aureus. PMID:24116120

  18. 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

  19. A case of epididymitis associated with Panton-Valentine leukocidin Staphylococcus aureus.

    PubMed

    Raychaudhuri, Malini; Chew, Pei Ru

    2012-08-01

    A new pattern of disease caused by Panton-Valentine leukocidin (PVL)-positive strains of Staphylococcus aureus is emerging in the UK and worldwide. Community-associated methicillin-resistant S aureus (MRSA) is more likely to produce PVL, a pore-forming cytotoxin inducing leucocyte lysis, which often infects young healthy individuals. The worldwide emergence and continually increasing prevalence of community-acquired PVL-MRSA have recently attracted high-profile media attention and prompted concern regarding the transmissibility and virulence. This paper reports a case of genitourinary tract infection associated with PVL-positive community-associated MRSA in an immunocompetent young man.

  20. 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.

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

    PubMed

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

    2015-04-21

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

  2. 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

  3. Phosphatidylglycerol homeostasis in glycerol-phosphate auxotrophs of Staphylococcus aureus

    PubMed Central

    2013-01-01

    Background The balanced synthesis of membrane phospholipids, fatty acids and cell wall constituents is a vital facet of bacterial physiology, but there is little known about the biochemical control points that coordinate these activities in Gram-positive bacteria. In Escherichia coli, the glycerol-phosphate acyltransferase (PlsB) plays a key role in coordinating fatty acid and phospholipid synthesis, but pathogens like Staphylococcus aureus have a different acyltransferase (PlsY), and the headgroup of the major membrane phospholipid, phosphatidylglycerol (PtdGro), is used as a precursor for lipoteichoic acid synthesis. Results The PlsY acyltransferase in S. aureus was switched off by depriving strain PDJ28 (ΔgpsA) of the required glycerol supplement. Removal of glycerol from the growth medium led to the rapid cessation of phospholipid synthesis. However, the continued utilization of the headgroup caused a reduction in PtdGro coupled with the accumulation of CDP-diacylglycerol and phosphatidic acid. PtdGro was further decreased by its stimulated conversion to cardiolipin. Although acyl-acyl carrier protein (ACP) and malonyl-CoA accumulated, fatty acid synthesis continued at a reduced level leading to the intracellular accumulation of unusually long-chain free fatty acids. Conclusions The cessation of new phospholipid synthesis led to an imbalance in membrane compositional homeostasis. PtdGro biosynthesis was not coupled to headgroup turnover leading to the accumulation of pathway intermediates. The synthesis of cardiolipin significantly increased revealing a stress response to liberate glycerol-phosphate for PtdGro synthesis. Acyl-ACP accumulation correlated with a decrease in fatty acid synthesis; however, the coupling was not tight leading to the accumulation of intracellular fatty acids. PMID:24238430

  4. Auranofin efficacy against MDR Streptococcus pneumoniae and Staphylococcus aureus infections.

    PubMed

    Aguinagalde, Leire; Díez-Martínez, Roberto; Yuste, Jose; Royo, Inmaculada; Gil, Carmen; Lasa, Íñigo; Martín-Fontecha, Mar; Marín-Ramos, Nagore Isabel; Ardanuy, Carmen; Liñares, Josefina; García, Pedro; García, Ernesto; Sánchez-Puelles, José M

    2015-09-01

    Auranofin is an FDA-approved, gold-containing compound in clinical use for the oral treatment of rheumatoid arthritis and has been recently granted by the regulatory authorities due to its antiprotozoal properties. A reprofiling strategy was performed with a Streptococcus pneumoniae phenotypic screen and a proprietary library of compounds, consisting of both FDA-approved and unapproved bioactive compounds. Two different multiresistant S. pneumoniae strains were employed in a sepsis mouse model of infection. In addition, an MRSA strain was tested using both the thigh model and a mesh-associated biofilm infection in mice. The repurposing approach showed the high potency of auranofin against multiresistant clinical isolates of S. pneumoniae and Staphylococcus aureus in vitro and in vivo. Efficacy in the S. pneumoniae sepsis model was obtained using auranofin by the oral route in the dose ranges used for the treatment of rheumatoid arthritis. Thioglucose replacement by alkyl chains showed that this moiety was not essential for the antibacterial activity and led to the discovery of a new gold derivative (MH05) with remarkable activity in vitro and in vivo. Auranofin and the new gold derivative MH05 showed encouraging in vivo activity against multiresistant clinical isolates of S. pneumoniae and S. aureus. The clinical management of auranofin, alone or in combination with other antibiotics, deserves further exploration before use in patients presenting therapeutic failure caused by infections with multiresistant Gram-positive pathogens. Decades of clinical use mean that this compound is safe to use and may accelerate its evaluation in humans. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Detection and analysis of Staphylococcus aureus isolates found in ambulances in the Chicago metropolitan area.

    PubMed

    Rago, James V; Buhs, Lieutenant Keith; Makarovaite, Viktorija; Patel, Esha; Pomeroy, Melissa; Yasmine, Christian

    2012-04-01

    Given the frequency with which many different strains of Staphylococcus aureus are found in various prehospital settings, this study sought to characterize S aureus isolates taken from one such environment. The objectives were to determine the frequency of S aureus in front-line, advanced life support (ALS) ambulances throughout the Chicago metropolitan area, and to generate antibiograms (antibiotic resistance profiles) for each S aureus isolate using 8 clinically relevant antibiotics. Samples were obtained from 26 sites in 71 ambulances from 34 different Chicago-area municipalities. Selected colonies that demonstrated a growth pattern consistent with that of S aureus were subjected to a latex agglutination test specific for S aureus. Antibiograms and genetic analyses were performed on all latex agglutination test-positive isolates. At least one S aureus isolate was found in approximately 69% of all ambulances in the study. Of all isolates detected, 77% showed resistance to at least one antibiotic, and 34% displayed resistance to 2 or more antibiotics. Some level of oxacillin resistance was found in 21% of isolates; however, only slightly more than half of these oxacillin-resistant isolates were found to carry the methicillin-resistant S aureus-specific SCCmec cassette. Some 12% of all isolates were ultimately determined to be methicillin-resistant S aureus, whereas the remaining 88% were methicillin-sensitive S aureus with varying antibiograms. Antibiotic resistance appears to be prevalent in S aureus isolates detected in Chicago area ALS ambulances. Given the ease with which S aureus can survive on inanimate surfaces and exchange antibiotic resistance elements, a conscientious approach to the application of existing cleaning techniques, especially in key ambulance sites, is needed. Future work will include further characterizing isolates using multiple techniques, as well as follow-up studies with interested municipalities. Copyright © 2012 Association for

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

    PubMed

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

    2006-10-15

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

  7. Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

    PubMed Central

    2016-01-01

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

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

    PubMed Central

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

    2011-01-01

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

  9. 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.

  10. Diversity of Staphylococcus aureus Isolates in European Wildlife.

    PubMed

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

    2016-01-01

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

  11. Diversity of Staphylococcus aureus Isolates in European Wildlife

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  13. Staphylococcus aureus – antimicrobial resistance and the immunocompromised child

    PubMed Central

    McNeil, J Chase

    2014-01-01

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

  14. 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.

  15. 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.

  16. 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

  17. Epistaxis and Staphylococcus aureus colonization in the nasal vestibule: is it a cause or consequence?

    PubMed

    Ulusoy, Seckin; Babaoglu, Gulcin; Catli, Tolgahan; San, Turhan; Cingi, Cemal

    2014-11-01

    The aim of this study was to investigate the relation between epistaxis and nasal colonization of Staphylococcus aureus in a population of patients with recurrent epistaxis. A total of 361 men and women were recruited, 245 patients with epistaxis (114 had crusting in the nasal vestibule; 131 did not) and 116 control subjects. A microbiology swab was taken from the anterior nasal cavity of each subject. Staphylococcus aureus was found to be more common in the epistaxis group when compared with the control group with a percentage of 31.8% and 4.3%, respectively (P < 0.05). There was no difference in the prevalence of S. aureus between the crust and non-crust groups (P > 0.05). When positive cultures were grouped and compared according to season, it was observed that the positive culture with epistaxis was much higher (44.82 %) in the autumn period. Staphylococcus aureus colonization in the nasal vestibule is more likely to be observed in individuals who have recurrent epistaxis than in those who do not have. It seems that this colonization may have a role in the etiology of epistaxis. However, with an altered medium of the nasal vestibule after each epistaxis period, it is also possible to speculate that this colonization is may be the consequence of epistaxis itself.

  18. 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.

  19. Short communication: Outbreak of methicillin-resistant Staphylococcus aureus (MRSA)-associated mastitis in a closed dairy herd.

    PubMed

    Guimarães, F F; Manzi, M P; Joaquim, S F; Richini-Pereira, V B; Langoni, H

    2017-01-01

    Cows are probably the main source of contamination of raw milk with Staphylococcus aureus. Mammary glands with subclinical mastitis can shed large numbers of Staph. aureus in milk. Because of the risk of this pathogen to human health as well as animal health, the aim of this paper was to describe an outbreak of mastitis caused by methicillin-resistant Staph. aureus (MRSA), oxacillin-susceptible mecA-positive Staph. aureus (OS-MRSA), and methicillin-susceptible Staph. aureus (MSSA) on a dairy farm. Milk samples were obtained from all quarters, showing an elevated somatic cell count by the California Mastitis Test. The isolates were identified by phenotypic and genotypic methods. Staphylococcus spp. were isolated from 53% (61/115) of the milk samples, with 60 isolates identified as Staph. aureus (98.4%) and 1 isolate identified as Staphylococcus epidermidis (1.6%). The presence of the mecA gene was verified in 48.3% of Staph. aureus isolates. Of the Staph. aureus isolates, 23.3% were MRSA and 25.0% were OS-MRSA. The total of mastitis cases infected with MRSA was 12.2%. The detection of this large percentage of mastitis cases caused by MRSA and OS-MRSA is of great concern for the animals' health, because β-lactams are still the most important antimicrobials used to treat mastitis. In addition, Staph. aureus isolates causing bovine mastitis represent a public health risk.

  20. 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

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

    PubMed

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

    2011-02-01

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

  2. 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

  3. 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

  4. 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.

  5. Superoxide dismutase activity in thermally stressed Staphylococcus aureus.

    PubMed Central

    Bucker, E R; Martin, S E

    1981-01-01

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

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

    PubMed

    Teow, Sin-Yeang; Ali, Syed Atif

    2015-11-01

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

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

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

    PubMed

    Baron, Ellen Jo; Tenover, Fred C

    2012-11-01

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

  10. Detection of methicillin-resistant Staphylococcus aureus in Iberian pigs.

    PubMed

    Porrero, M C; Wassenaar, T M; Gómez-Barrero, S; García, M; Bárcena, C; Alvarez, J; Sáez-Llorente, J L; Fernández-Garayzábal, J F; Moreno, M A; Domínguez, L

    2012-04-01

    Iberian pigs are bred in Spain for the production of high-value dry-cured products, whose export volumes are increasing. Animals are typically reared outdoors, although indoor farming is becoming popular. We compared carriage of methicillin-resistant Staphylococcus aureus (MRSA) in Iberian pigs, raised indoors and outdoors, with intensively farmed Standard White pigs. From June 2007 to February 2008, 106 skin swabs were taken from Iberian pigs and 157 samples from SWP at slaughterhouses in Spain. We found that Iberian pigs carried MRSA, although with a significantly lower prevalence (30/106; 28%) than SWP (130/157; 83%). A higher prevalence of indoor Iberian pigs compared with animals reared under outdoor conditions was not significant; however, all but one positive indoor Iberian pig samples were detected from one slaughterhouse. Overall, 16 different spa types were identified, with t011 predominating in all three animal populations. A subset of isolates was characterized by MLST. Most of these belonged to ST398. MRSA isolates from Iberian pigs presented a higher susceptibility to antibiotics than those isolated from SWP. Despite limited contact with humans, pigs raised outdoors are colonized by an MRSA population that genetically overlaps with that of intensively farmed pigs, although antimicrobial resistance is lower. To our knowledge, this is the first detection of MRSA in food animals raised in free-range conditions. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  11. Methicillin-resistant Staphylococcus aureus: source control and surveillance organization.

    PubMed

    Tacconelli, E

    2009-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has been a common nosocomial pathogen since the 1960s, and has become a major problem in hospitals worldwide. Patients and the public are increasingly seeing MRSA and rates of MRSA infections as indicators of the quality of patient care. The control measures aimed at reducing the spread of MRSA among hospitals and communities include the following: education of healthcare workers, with implementation and adherence to hand-washing practices; restriction of antibiotic use; active surveillance cultures (ASCs); contact isolation of MRSA-positive patients; and pre-emptive isolation of high-risk patients. However, despite these interventions, MRSA is still endemic in many hospitals worldwide. In particular, the role of ASCs is still under debate. International guidelines suggest that extensive ASCs should only be used in intensive-care units (ICUs), and routine screening of all hospital admissions is not usually advocated. Local decisions can be made on the basis of types of risk factor of non-ICU patients. Before starting ASCs, laboratories should be prepared for the workload, and the turn-around time for screening tests should be reduced and arrangements made to monitor the effectiveness of this intervention. Most recently, rapid methods for molecular detection of MRSA colonization have been developed. Published studies differ in their settings (ICU, medical wards, surgical wards), choice of patient population, severity of illness, hospital infection control measures, and study design. The existing evidence does not support the wide application of rapid molecular screening for MRSA.

  12. 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. © 2011 The Authors; Hemodialysis International © 2011 International Society for Hemodialysis.

  13. 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

  14. Antibiotic resistance and clonal diversity of invasive Staphylococcus aureus in the rural Ashanti Region, Ghana.

    PubMed

    Dekker, Denise; Wolters, Manuel; Mertens, Eva; Boahen, Kennedy Gyau; Krumkamp, Ralf; Eibach, Daniel; Schwarz, Norbert G; Adu-Sarkodie, Yaw; Rohde, Holger; Christner, Martin; Marks, Florian; Sarpong, Nimako; May, Jürgen

    2016-11-29

    Staphylococcus aureus is among the most common pathogens isolated from blood cultures in Ghana; yet the epidemiology of blood infections in rural settings is poorly described. This study aims to investigate antimicrobial susceptibility and clonal diversity of S. aureus causing bloodstream infections in two hospitals in the Ashanti Region, Ghana. Blood cultures were performed for all febrile patients (≥37.5 °C) on hospital admission. Antibiotic susceptibility testing for S. aureus isolates was carried out by the VITEK 2 system. Multiplex polymerase chain reaction (PCR) was used to detect S. aureus-specific nuc gene, Panton-Valentine leukocidin (PVL), and methicillin-resistant S. aureus (MRSA)-specific mecA and mecC genes. The population structure of S. aureus was assessed by spa typing. In total, 9,834 blood samples were cultured, out of which 0.6% (n = 56) were positive for S. aureus. Multidrug resistance (MDR) was detected in 35.7% (n = 20) of the S. aureus strains, of which one was a MRSA. The highest rate of antibiotic resistance was seen for commonly available antibiotics, including penicillin (n = 55; 98.2%), tetracycline (n = 32; 57.1%) and trimethoprim/sulfamethoxazole (n = 26; 46.4%). Of all S. aureus strains, 75.0% (n = 42) carried the PVL-encoding genes. We found 25 different spa types with t355 (n = 11; 19.6%), t314 (n = 8; 14.3%), t084 (n = 8; 14.3%) and t311 (n = 5; 8.9%) being predominant. The study exhibited an alarmingly large level of antibiotic resistance to locally available antibiotics. The frequency of genetically diverse and PVL-positive methicillin-sensitive S. aureus (MSSA) was high and could represent a reservoir for the emergence of virulent PVL-positive MRSA clones.

  15. Identification of Single Nucleotide Polymorphisms Associated with Hyperproduction of Alpha-Toxin in Staphylococcus aureus

    PubMed Central

    Yang, Junshu; Yan, Meiying; Doll, Katherine; Bey, Russell; Ji, Yinduo

    2011-01-01

    The virulence factor α-toxin (hla) is needed by Staphylococcus aureus in order to cause infections in both animals and humans. Although the complicated regulation of hla expression has been well studied in human S. aureus isolates, the mechanisms of of hla regulation in bovine S. aureus isolates remain undefined. In this study, we found that many bovine S. aureus isolates, including the RF122 strain, generate dramatic amounts of α-toxin in vitro compared with human clinical S. aureus isolates, including MRSA WCUH29 and MRSA USA300. To elucidate potential regulatory mechanisms, we analyzed the hla promoter regions and identified predominant single nucleotide polymorphisms (SNPs) at positions −376, −483, and −484 from the start codon in α-toxin hyper-producing isolates. Using site-directed mutagenesis and hla promoter-gfp-luxABCDE dual reporter approaches, we demonstrated that the SNPs contribute to the differential control of hla expression among bovine and human S. aureus isolates. Using a DNA affinity assay, gel-shift assays and a null mutant, we identified and revealed that an hla positive regulator, SarZ, contributes to the involvement of the SNPs in mediating hla expression. In addition, we found that the bovine S. aureus isolate RF122 exhibits higher transcription levels of hla positive regulators, including agrA, saeR, arlR and sarZ, but a lower expression level of hla repressor rot compared to the human S. aureus isolate WCUH29. Our results indicate α-toxin hyperproduction in bovine S. aureus is a multifactorial process, influenced at both the genomic and transcriptional levels. Moreover, the identification of predominant SNPs in the hla promoter region may provide a novel method for genotyping the S. aureus isolates. PMID:21494631

  16. 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.

  17. 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

    2017-06-01

    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.

  18. 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).

  19. Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus Isolates in Fishery Products in Iran

    PubMed Central

    Arfatahery, Noushin; Davoodabadi, Abolfazl; Abedimohtasab, Taranehpeimaneh

    2016-01-01

    Staphylococcus aureus is one of the most common causes of seafood-borne diseases worldwide, which are attributable to the contamination of food by preformed enterotoxins. In this study, a total of 206 (34.3%) Staphylococcus aureus strains were obtained from 600 fish and shrimp samples and were tested for their antimicrobial susceptibility. We assessed the prevalence of the genes responsible for the staphylococcal enterotoxins (SEA, SEB) and toxic shock syndrome toxin 1 (TSST-1) genes. The results indicated that 34% of aqua food samples were contaminated with S. aureus, and 23.8% of these isolates were mec-A-positive. Sixty-four percent of the strains isolated from contaminated seafood was enterotoxigenic S. aureus, and 28.2% of SEs were MRSA-positive. The most prevalent genotype was characterized by the presence of the sea gene (45.2%), followed by the seb gene (18.5%), and the tst gene encoding TSST-1 was found in eight strains (3.9%). Of the 206 S. aureus isolates, 189 strains (84.9%) were resistant to at least one antibiotic. Given the frequent outbreaks of enterotoxigenic MRSA, it is necessary to make revisions to mandatory programmes to facilitate improved hygiene practices during fishing, aquaculture, processing, and sales to prevent the contamination of fishery products in Iran. PMID:27694813

  20. Wall teichoic acids prevent antibody binding to epitopes within the cell wall of Staphylococcus aureus.

    PubMed

    Gautam, Samir; Kim, Taehan; Lester, Evan; Deep, Deeksha; Spiegel, David A

    2016-01-15

    Staphylococcus aureus is a Gram-positive bacterial pathogen that produces a range of infections including cellulitis, pneumonia, and septicemia. The principle mechanism in antistaphylococcal host defense is opsonization with antibodies and complement proteins, followed by phagocytic clearance. Here we use a previously developed technique for installing chemical epitopes in the peptidoglycan cell wall to show that surface glycopolymers known as wall teichoic acids conceal cell wall epitopes, preventing their recognition and opsonization by antibodies. Thus, our results reveal a previously unrecognized immunoevasive role for wall teichoic acids in S. aureus: repulsion of peptidoglycan-targeted antibodies.

  1. Structure of the Cell Wall Anchor of Surface Proteins in Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Schneewind, Olaf; Fowler, Audree; Faull, Kym F.

    1995-04-01

    Many surface proteins are anchored to the cell wall of Gram-positive bacteria and are involved in the pathogenesis of these organisms. A hybrid molecule was designed that, when expressed in Staphylococcus aureus, was anchored to the cell wall and could be released by controlled enzymatic digestion. By a combination of molecular biology and mass spectrometry techniques, the structure of the cell wall anchor of surface proteins in S. aureus was revealed. After cleavage of surface proteins between threonine and glycine of the conserved LPXTG motif, the carboxyl of threonine is amide-linked to the free amino group of the pentaglycine crossbridge in the staphylococcal cell wall.

  2. Inducible resistance to clindamycin in Staphylococcus aureus: validation of Vitek-2 against CLSI D-test.

    PubMed

    Gardiner, B J; Grayson, M L; Wood, G M

    2013-02-01

    Inducible resistance to clindamycin in Staphylococcus aureus is common but not easily identified by routine testing, and can result in treatment failure if not detected. The gold standard method is the D-test described by the Clinical and Laboratory Standards Institute (CLSI). The Vitek-2 AST-P612 card contains an 'inducible clindamycin resistance' (ICR) test. We aimed to determine the accuracy of the Vitek-2 ICR test compared to the D-test. Isolates of erythromycin non-susceptible, clindamycin susceptible Staphylococcus aureus were identified. Routine antimicrobial susceptibility testing was performed using the Vitek-2 AST-P612 card, including the ICR test, and compared against the D-test. 217 isolates were obtained. All of the 191 isolates that were ICR positive were D-test positive. Of the 27 ICR negative isolates, 10 (37%) were D-test positive [9 methicillin-sensitive S. aureus (MSSA), 1 methicillin-resistant S. aureus (MRSA)]. This correlates with a specificity of 100%, sensitivity of 95%, positive predictive value of 100%, and negative predictive value of 72%. The ICR test is reliable in the presence of a positive result; however there is a false negative rate of approximately one in four. This will lead to susceptibility reporting errors, with potentially serious clinical implications. A negative ICR should be confirmed by CLSI D-test before reporting clindamycin as susceptible where the organism is not susceptible to erythromycin.

  3. 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

  4. 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

  5. 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.

  6. 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/ .

  7. Tracheal aspirate Gram stain has limited sensitivity and specificity for detecting Staphylococcus aureus.

    PubMed

    Tetenta, Sodienye; Metersky, Mark L

    2011-01-01

    The increasing incidence of respiratory infections due to methicillin resistant Staphylococcus aureus has resulted in increased empirical use of antibiotics active against this pathogen. There are limited data available as to whether the Gram stain of respiratory tract secretions accurately predicts growth of S. aureus. We theorized that the distinctive morphology of S. aureus would allow rapid, accurate identification of the organism in respiratory secretions. The authors reviewed all available Gram stains of tracheal aspirates sent to our hospital's microbiology laboratory between 1 April 2008 and 31 October 2008, while blinded to the culture result, and recorded the presence or absence of organisms with a morphology consistent with S. aureus. These results were correlated with the semiquantitative culture result. Among 136 tracheal aspirates studied, 50 (37%) grew S. aureus. The Gram stain was read as positive for organisms consistent with S. aureus in 34 of these. Among 86 samples that did not grow S. aureus, the Gram stain was read as negative in 62. Therefore, the Gram stain had a sensitivity of 68%, a specificity of 72%, a negative predictive value of 80% and a positive predictive value of 59% for culture of S. aureus. False negative Gram stains were more likely when the culture revealed only rare or small growth of S. aureus (P = 0.01). In this study, the tracheal aspirate Gram stain read by an experienced clinician who was not a microbiologist, was not accurate enough to reliably predict the growth of S. aureus. © 2010 The Authors. Respirology © 2010 Asian Pacific Society of Respirology.

  8. 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

  9. 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

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

    PubMed Central

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

    2008-01-01

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

  11. 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

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

    PubMed

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

    2015-01-01

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

  13. 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.

  14. 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

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

    PubMed

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

    2016-11-01

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

  16. 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

  17. 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

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

    PubMed

    Devriese, L A; Oeding, P

    1976-11-01

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

  19. Identification and Characterization of the Multidrug Resistance Gene cfr in a Panton-Valentine Leukocidin-Positive Sequence Type 8 Methicillin-Resistant Staphylococcus aureus IVa (USA300) Isolate▿

    PubMed Central

    Shore, Anna C.; Brennan, Orla M.; Ehricht, Ralf; Monecke, Stefan; Schwarz, Stefan; Slickers, Peter; Coleman, David C.

    2010-01-01

    The staphylococcal cfr gene mediates resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins, and streptogramin A, a phenotype that has been termed PhLOPSA. The cfr gene has mainly been associated with coagulase-negative staphylococcal isolates from animals, and only a few cfr-positive methicillin-resistant Staphylococcus aureus (MRSA) isolates have been described so far. This study reports the first description of a cfr-positive MRSA isolate (M05/0060) belonging to the pandemic Panton-Valentine leukocidin (PVL)-positive sequence type 8 MRSA IVa/USA300 (ST8-MRSA-IVa/USA300) clone. The cfr gene was detected in M05/0060 using a DNA microarray which was used to screen PVL-positive MRSA isolates for the presence of virulence genes, typing markers, and antimicrobial resistance genes. Antimicrobial susceptibility testing revealed that M05/0060 exhibited the cfr-associated resistance phenotype. Molecular analysis identified the presence of cfr and a second phenicol resistance gene, fexA, on a novel 45-kb conjugative plasmid, which was designated pSCFS7. Within pSCFS7, a DNA segment consisting of cfr, a truncated copy of insertion sequence IS21-558, and a region with homology to the DNA invertase gene bin3 of transposon Tn552 from Bacillus mycoides was integrated into the transposase gene tnpB of the fexA-carrying transposon Tn558. The emergence of a multidrug-resistant cfr-positive variant of ST8-MRSA-IVa/USA300 is alarming and requires ongoing surveillance. Moreover, the identification of a novel conjugative plasmid carrying the cfr gene indicates the ability of cfr to spread to other MRSA strains. PMID:20921317

  20. 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

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

    PubMed

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

    2016-07-01

    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. This study determined the prevalence of methicillin-resistant S. aureus and different spa types in S. aureus clinical isolates. 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. 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. 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.

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

    PubMed Central

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

    2016-01-01

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

  3. 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

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

    PubMed

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

    2017-01-01

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

  5. 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

  6. Clonal distribution of enterotoxigenic Staphylococcus aureus on handles of handheld shopping baskets in supermarkets.

    PubMed

    Mizumachi, E; Kato, F; Hisatsune, J; Tsuruda, K; Uehara, Y; Seo, H; Sugai, M

    2011-02-01

    Shopping carts and handheld shopping baskets in supermarkets are subject to accidental bacterial contamination through contacts with a variety of food. We investigated the prevalence of Staphylococcus aureus on the handles of handheld shopping baskets in four supermarkets distantly located in Osaka district, Japan. Fifty two strains of Staph. aureus were isolated from 760 basket handles. Among these, six strains were positive for staphylococcal enterotoxin B (SEB) production, representing 12% of total. This SEB producer ratio is considerably higher than among Staph. aureus isolated from nasal swabs of the supermarket workers (2%) and from independently collected clinical specimens (4%). These SEB-producing Staph. aureus strains from the basket handles are clonal and belong to ST12. Coagulase typing showed that they are in group VII, which is the most common cause of food poisoning in Japan. Biofilm assays indicated that SEB gene (seb)-positive strains including this clone produced a significantly higher amount of biofilm than seb-negative strains. The frequent isolation of seb-positive Staph. aureus on shopping basket handles raises the possibility that they could be a hidden reservoir for Staph. aureus with a potential to cause food poisoning and draws attention to the importance of shopping basket sanitation. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  7. 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

  8. 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.

  9. Characterization of a Staphylococcus aureus small colony variant (SCV) associated with persistent bovine mastitis.

    PubMed

    Atalla, Heba; Gyles, Carlton; Jacob, Christian L; Moisan, Helene; Malouin, François; Mallard, Bonnie

    2008-12-01

    Staphylococcus aureus is a common cause of bovine mastitis and foodborne and other diseases in humans. This study tested the hypothesis that small colony variants (SCVs) of S. aureus are implicated in chronic bovine mastitis. Six S. aureus isolates from foremilk samples from 11 chronically infected cows were investigated. Five isolates had typical morphology and were hemolytic and coagulase positive; one was a heterogeneous population of typical and SCV phenotype (tiny nonhemolytic colonies). In the presence of gentamicin, three of the previously typical S. aureus developed SCVs that were confirmed as S. aureus by biochemical and genetic analyses; these SCVs reverted to the typical form on antibiotic-free medium. The SCV isolate (Heba3231) from the heterogeneous population had a slow growth rate and prolonged lag phase and did not revert during 10 h of incubation. Transcriptional analysis showed that SCV Heba3231 had reduced expression of agr, hla, and coa and increased expression of indicators of fermentation pathways compared to the parent strain. Invasion of and persistence in a primary culture of bovine aortic endothelial cells (BAEC) showed that SCV Heba3231 had minimal deleterious effects, whereas the parent strain or the Newbould 305 strain caused severe damage. Recovery of the parent strain from BAEC yielded a mixture of the parent and SCV phenotypes. This study reports for the first time the isolation of S. aureus SCV from persistent bovine mastitis and suggests that SCV may be an important contributor to the prolonged survival of S. aureus in some cases of mastitis.

  10. Phenotypic and genotypic characterization of Staphylococcus aureus isolates in milk from flocks diagnosed with subclinical mastitis.

    PubMed

    Xavier, A R E O; Almeida, A C; Souza, C N; Silva, L M V; Ruas, A X A; Sanglard, D A; Júnior, A F M; Oliveira, A M E; Xavier, M A S

    2017-06-29

    The Staphylococcus aureus is the most common isolated microorganism in ruminant animal species diagnostic with clinical or subclinical mastitis. Dairy herds with these diseases can transfer S. aureus into the milk supply, which can lead to food poisoning in humans. The objective of this study was to evaluate the profile of antimicrobial susceptibility, the presence of femA gene, the genetic relationships among isolates of S. aureus obtained from milk originating from flocks diagnosed with subclinical mastitis in nine rural properties in the northern of Minas Gerais State. To this end, 498 samples of bovine milk tested positive for the California mastitis test (CMT) were subjected to morphological methods and biochemical patterns for microbiological presumptive identification of S. aureus. The PCR test with the genetic marker femA was used to confirm the species S. aureus. All the 26 isolates presumptively identified as S. aureus amplified a fragment of 132 bp corresponding to the femA gene. The profile of antimicrobial susceptibility was performed according to the disk-diffusion methodology and two isolates were susceptible to all the antibiotics tested. The drug multiresistence was found in 80.76% of the isolates. The determination of the genetic profile and the clonal relationship among the isolates was performed by the method of DNA RAPD-PCR polymorphism. The S. aureus isolates were divided into two groups with 26 distinct subgroups. The analysis of RAPD-PCR showed no genetic diversity among them, heterogeneous profile and absence of clonality.

  11. 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

  12. 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.

  13. 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.

  14. 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.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-04-16

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

  17. Predictors of Staphylococcus aureus Colonization and Results after Decolonization

    PubMed Central

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

    2016-01-01

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

  18. 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.

  19. 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

  20. Methicillin-resistant Staphylococcus aureus (MRSA) pediatric tympanostomy tube otorrhea.

    PubMed

    Cheng, Jeffrey; Javia, Luv

    2012-12-01

    To describe our experience and clinical outcomes with the management of pediatric tympanostomy tube otorrhea secondary to methicillin-resistant Staphylococcus aureus (MRSA). Retrospective review of pediatric patients (age <18) diagnosed with culture-positive MRSA tympanostomy tube otorrhea. MRSA positive ear cultures in the presence of tympanostomy tubes were identified in 41 patients (6.3%). The average age was 2.9 years old. In all cases, culture results indicated sensitivity to trimethoprim/sulfamethoxazole and gentamicin; resistance to fluoroquinolones and clindamycin occurred in 87.8% and 61.0% of cases, respectively. Fluoroquinolone and sulfacetamide ototopical medications were found to be associated with successful otorrhea resolution (p=0.005 and 0.009, respectively). Adjunctive therapy with oral antibiotics, bactrim and clindamycin (p=0.172 and 0.877, respectively), did not improve resolution rates with medical treatment. Tympanostomy tube removal was more successful than medical therapy alone (p<0.0001). Appropriately treated recurrent or recalcitrant tympanostomy tube-related otorrhea should raise the suspicion for MRSA-related tympanostomy tube otorrhea. Fluoroquinolone ototopical medication should be considered for initial therapy. Sulfacetamide ototopical medication can be considered for failures. The adjunctive use of oral antibiotics, bactrim and clindamycin, and aminoglycoside ototopical medications did not improve clinical outcomes for medical therapy alone. We believe that some consideration be given to removal of the tympanostomy tube with or without replacement, after an initial treatment period with fluoroquinolone and/or sulfacetamide otopical medications. Our findings seem to suggest an improved rate with tympanostomy tube removal over medical therapy alone (p<0.0001). No standard management guidelines currently exist. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  1. Prevention and control of methicillin-resistant Staphylococcus aureus.

    PubMed

    Humphreys, H; Grundmann, H; Skov, R; Lucet, J-C; Cauda, R

    2009-02-01

    Recent efforts to combat infections have focused on pharmaceutical interventions. However, the global spread of antimicrobial resistance calls for the reappraisal of personal and institutional hygiene. Hygiene embodies behavioural and procedural rules that prevent bacterial transmission. Consequently, the chance of spreading bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is significantly reduced. Hygiene is part of the primacy and totality of patient care, ensuring that no harm is done. Any prevention and control strategy must be underpinned by changes in attitude, embraced by all. The major components of preventing and controlling MRSA include hand and environmental hygiene (as part of standard precautions), patient isolation, and patient/staff decolonization. Improving hand hygiene practice is especially important where the risk of infection is highest, e.g. in intensive care. Physical isolation has two advantages: the physical barrier interrupts transmission, and this barrier emphasizes that precautions are required. With limited isolation facilities, risk assessment should be conducted to indicate which patients should be isolated. Environmental hygiene, although important, has a lower priority than standard precautions. When a patient is ready for discharge (home) or transfer (to another healthcare facility), the overall interests of the patient should take priority. All patients should be informed of their MRSA-positive status as soon as possible. Because of increased mupirocin resistance, a selective approach to decolonization should be taken. When MRSA-positive staff are identified, restricting their professional activity will depend on the nature of their work. Finally, politicians and others need to commit to providing the necessary resources to maximize MRSA prevention and control.

  2. Antimicrobial Resistance and Molecular Characterization of Staphylococcus aureus Causing Childhood Pneumonia in Shanghai

    PubMed Central

    Song, Zhen; Gu, Fei-Fei; Guo, Xiao-Kui; Ni, Yu-Xing; He, Ping; Han, Li-Zhong

    2017-01-01

    Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing pneumonia among children. To estimate the prevalence and molecular properties of S. aureus in children pneumonia in Shanghai, China, 107 hospitalized children with S. aureus pneumonia from two children's hospitals from January 2014 through June 2015 were studied. S. aureus isolates from the respiratory specimens were characterized by antimicrobial susceptibility, agr typing, toxin genes, multilocus sequence typing (MLST), spa, and SCCmec typing. Fifty-eight (54.2%, 58/107) were MSSA (methicillin-susceptible Staphylococcus aureus) and 49 (45.8%, 49/107) were MRSA. No isolates were found resistant to teicoplanin, sulfamethoxazole/trimethoprim, rifampicin, quinupristin/dalfopristin, linezolid, or vancomycin. However, these isolates showed high resistant rates to erythromycin, fosfomycin-trometamol and clindamycin. The agrI (87/107, 81.3%) was the most common agr allele, followed by agrIII(10/107, 9.3%), agrII(9/107, 8.4%), and agrIV(1/107, 0.9%). Six pvl-positive isolates (3 MRSA and 3 MSSA) and 7 isolates of livestock associated clone ST398 (4 MRSA, 3 MSSA) were identified. CC59 was found in 35 isolates (33 MRSA and 2 MSSA), constituting majority of MRSA (33/49, 67.35%). The dominant CC were CC59 (32.7%), CC188 (13.1%), CC7 (12.1%) and CC398 (9.3%) while t172 (16.8%), t189 (12.1%), t437 (9.3%), and t091 (9.3%) were the most common spa types. In conclusion, more particular concern should appeal to ST59-SCCmecIV-t172/t437 as it is the most common epidemic clone causing pneumonia among children in Shanghai. PMID:28377752

  3. Staphylococcus aureus carriage at admission predicts early-onset pneumonia after burn trauma.

    PubMed

    Fournier, A; Voirol, P; Krähenbühl, M; Bonnemain, C-L; Fournier, C; Dupuis-Lozeron, E; Pantet, O; Pagani, J-L; Revelly, J-P; Sadeghipour, F; Eggimann, P; Que, Y-A

    2017-03-01

    Early-onset pneumonia (EOP) is frequent after burn trauma, increasing morbidity in the critical resuscitation phase, which may preclude early aggressive management of burn wounds. Currently, however, preemptive treatment is not recommended. The aim of this study was to identify predictive factors for EOP that may justify early empirical antibiotic treatment. Data for all burn patients requiring ≥4 h mechanical ventilation (MV) who were admitted between January 2001 and October 2012 were extracted from the hospital's computerized information system. We reviewed EOP episodes (≤7 days) among patients who underwent endotracheal aspiration (ETA) within 5 days after admission. Univariate and multivariate analyses were performed to identify independent factors associated with EOP. Logistic regression was used to identify factors predicting EOP development. During the study period, 396 burn patients were admitted. ETA was performed within 5 days in 204/290 patients receiving ≥4 h MV. One hundred and eight patients developed EOP; 47 cases were caused by Staphylococcus aureus, 37 by Haemophilus influenzae, and 23 by Streptococcus pneumoniae. Among the 33 patients showing S. aureus positivity on ETA samples, 16 (48.5 %) developed S. aureus EOP. Among the 156 S. aureus non-carriers, 16 (10.2 %) developed EOP. Staphylococcus aureus carriage independently predicted EOP (p < 0.0001). We identified S. aureus carriage as an independent and strong predictor of EOP. As rapid point-of-care testing for S. aureus is readily available, we recommend testing of all patients at admission for burn trauma and the consideration of early preemptive treatment in all positive patients. Further studies are needed to evaluate this new strategy.

  4. 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

  5. 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.

  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

    Junge, Sibylle; Görlich, Dennis; 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; Kahl, Barbara C

    2016-01-01

    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. 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. 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). 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. ClinicalTrials.gov NCT00669760.

  8. Ocurrence of Staphylococcus aureus and multiplex pcr detection of classic enterotoxin genes in cheese and meat products

    PubMed Central

    Pelisser, Marcia Regina; Klein, Cátia Silene; Ascoli, Kelen Regina; Zotti, Thaís Regina; Arisi, Ana Carolina Maisonnave

    2009-01-01

    Multiplex PCR was used to investigate the presence of enterotoxins genes (sea, seb, sec, sed and see) and femA gene (specific for Staphylococcus aureus) in coagulase-positive staphylococci (CPS) isolated from cheese and meat products. From 102 CPS isolates, 91 were positive for femA, 10 for sea, 12 for sed and four for see. PMID:24031334

  9. 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.

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

    PubMed

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

    2013-05-01

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

  11. Genetic Diversity and Virulence Potential of Staphylococcus aureus Isolated from Crayfish (Procambarus clarkii).

    PubMed

    Dong, Xingxing; Wang, Xiaohong; Chen, Xingchun; Yan, Zhiyun; Cheng, Jing; Gao, Liangliang; Liu, Yuan; Li, Jinquan

    2017-01-01

    Staphylococcus aureus, a commensal and a pathogenic bacterium, causes a wide variety of diseases in humans and animals with a high impact on public health and the livestock industry. The risk of zoonotic transmission to humans highlights the need to understand the molecular ecology of S. aureus in foods. In this study, we obtained 25 S. aureus isolates from 39 crayfish samples in Hubei, China. PCR was applied for detection of presence of virulence and methicillin resistance genes in the pathogen genome. The result revealed that all of the 25 S. aureus isolates harbored at least four virulence genes, and 64 % of them were positive for five or more virulence genes. The most predominant virulence genes were coa, α-HL and β-HL genes (100 %), followed by sea (68 %), fnbA (60 %), tsst-1 (36 %), while none of the examined isolates presented positive for mecA gene conferring methicillin resistance. Subsequently, all of the isolates were assessed for phenotypic biofilm formation with the microtiter plate assay. The results showed 92 % isolates could produce biofilm with different forming capacity. Multilocus sequence typing divided the isolates into five sequence types (STs), three of which (ST1920, ST188 and ST398) were the same with the isolates from livestock and clinic in China. This study provides preliminary insights into the genetic diversity and virulence gene profiles of S. aureus from crayfish, suggesting that S. aureus isolates from crayfish is a potential hazard for consumers and deserves further attention.

  12. 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

  13. 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.

  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. 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

  16. 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.

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

    PubMed Central

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

    2013-01-01

    Background Staphylococcus aureus is a major cause of healthcare associated mortality, but like many important bacterial pathogens, it is a common constituent of the normal human body flora. Around a third of healthy adults are carriers. Recent evidence suggests that evolution of S. aureus during