scholarly journals Commercially Distributed Meat as a Potential Vehicle for Community-Acquired Methicillin-Resistant Staphylococcus aureus

2012 ◽  
Vol 78 (8) ◽  
pp. 2797-2802 ◽  
Author(s):  
Kikuyo Ogata ◽  
Hiroshi Narimatsu ◽  
Masahiro Suzuki ◽  
Wataru Higuchi ◽  
Tatsuo Yamamoto ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Susceptibility ◽  
Methicillin Resistant ◽  
Content Type ◽  
Reading Frame ◽  
Type Iv ◽  
Mrsa Infection ◽  
Stool Samples ◽  
Mrsa Strains ◽  
Meat Samples

ABSTRACTThe incidence of community-acquired methicillin-resistantStaphylococcus aureus(CA-MRSA) infection has been increasing; however, the sources of infection remain unclear. Therefore, we investigated the involvement of meat as a possible mediator of CA-MRSA infection. We examined the distribution of MRSA strains in commercially distributed raw meat samples (n= 197) and diarrheal stool samples of outpatients (n= 1,287) that were collected in Oita Prefecture, Japan, between 2003 and 2009 for routine legal inspections. Fourteen MRSA strains were isolated from three meat and 11 stool samples. Among these, seven isolates from three meat and four stool samples exhibited the same epidemiological marker profiles [coagulase type III, staphylococcal enterotoxin C, staphylococcal chromosomal cassettemec(SCCmec) type IV, ST8,spatype 606 (t1767), and toxic shock syndrome toxin-1 (TSST-1) producing type]. Furthermore, of the seven strains, three isolates from two meat samples and one stool sample collected in 2007 exhibited completely identical characteristics with respect to phage open reading frame (ORF) typing, pulsed-field gel electrophoresis, and drug susceptibility profiles. The results suggest that commercially distributed meat could play a role in the prevalence of CA-MRSA in the community.

scholarly journals Comparative Genomics of Vancomycin-Resistant Staphylococcus aureus Strains and Their Positions within the Clade Most Commonly Associated with Methicillin-Resistant S. aureus Hospital-Acquired Infection in the United States

mBio ◽  
2012 ◽  
Vol 3 (3) ◽  
Author(s):  
Veronica N. Kos ◽  
Christopher A. Desjardins ◽  
Allison Griggs ◽  
Gustavo Cerqueira ◽  
Andries Van Tonder ◽  
...  
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
The United States ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Infection ◽  
Vancomycin Resistant ◽  
Foreign Dna ◽  
Mrsa Strains ◽  
Hospital Acquired

ABSTRACTMethicillin-resistantStaphylococcus aureus(MRSA) strains are leading causes of hospital-acquired infections in the United States, and clonal cluster 5 (CC5) is the predominant lineage responsible for these infections. Since 2002, there have been 12 cases of vancomycin-resistantS. aureus(VRSA) infection in the United States—all CC5 strains. To understand this genetic background and what distinguishes it from other lineages, we generated and analyzed high-quality draft genome sequences for all available VRSA strains. Sequence comparisons show unambiguously that each strain independently acquired Tn1546and that all VRSA strains last shared a common ancestor over 50 years ago, well before the occurrence of vancomycin resistance in this species. In contrast to existing hypotheses on what predisposes this lineage to acquire Tn1546, the barrier posed by restriction systems appears to be intact in most VRSA strains. However, VRSA (and other CC5) strains were found to possess a constellation of traits that appears to be optimized for proliferation in precisely the types of polymicrobic infection where transfer could occur. They lack a bacteriocin operon that would be predicted to limit the occurrence of non-CC5 strains in mixed infection and harbor a cluster of unique superantigens and lipoproteins to confound host immunity. A frameshift indprA, which in other microbes influences uptake of foreign DNA, may also make this lineage conducive to foreign DNA acquisition.IMPORTANCEInvasive methicillin-resistantStaphylococcus aureus(MRSA) infection now ranks among the leading causes of death in the United States. Vancomycin is a key last-line bactericidal drug for treating these infections. However, since 2002, vancomycin resistance has entered this species. Of the now 12 cases of vancomycin-resistantS. aureus(VRSA), each was believed to represent a new acquisition of the vancomycin-resistant transposon Tn1546from enterococcal donors. All acquisitions of Tn1546so far have occurred in MRSA strains of the clonal cluster 5 genetic background, the most common hospital lineage causing hospital-acquired MRSA infection. To understand the nature of these strains, we determined and examined the nucleotide sequences of the genomes of all available VRSA. Genome comparison identified candidate features that position strains of this lineage well for acquiring resistance to antibiotics in mixed infection.

scholarly journals Methicillin-Resistant Staphylococcus aureus spa Type t002 Outbreak in Horses and Staff at a Veterinary Teaching Hospital after Its Presumed Introduction by a Veterinarian

2015 ◽  
Vol 53 (9) ◽  
pp. 2827-2831 ◽  
Author(s):  
Amir Steinman ◽  
Samira Masarwa ◽  
Sharon Tirosh-Levy ◽  
Dan Gleser ◽  
Gal Kelmer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Teaching Hospital ◽  
Large Animal ◽  
Prevalence Survey ◽  
Methicillin Resistant ◽  
Content Type ◽  
Staff Members ◽  
Cross Transmission ◽  
Mrsa Infection ◽  
Mrsa Strains

Methicillin-resistantStaphylococcus aureus(MRSA) infection and colonization, involving MRSA strains which differ from common human health care-associated clones, have become serious emerging conditions in equine veterinary hospitals. In 2010, MRSAspatype t535 caused an outbreak involving both horses and personnel in a veterinary teaching hospital in Israel. Since then, surveillance continued, and occasional MRSA isolation occurred. Two years later, MRSA of anotherspatype, t002, was isolated from a veterinarian and, 3 weeks later, from a horse. The appearance ofspatype t002, a common clone in human medicine in Israel, among both personnel and horses, prompted a point-prevalence survey of hospital personnel and hospitalized horses. Fifty-nine staff members (n= 16 equine;n= 43, other) and 14 horses were screened. Ten of 59 staff members (16.9%) and 7 of 14 horses (50%) were MRSA carriers. Among the staff, 44% of large animal department (LAD) personnel, compared with only 7% of non-LAD personnel, were carriers. Isolates from all horses and from 9 of 10 personnel were found to be of MRSAspatype t002. This clone was later isolated from an infected postoperative wound in a hospitalized horse. Measures were taken to contain transmission between horses and personnel, as was done in the previous outbreak, resulting in reduction of transmission and, finally, cessation of cross-transmission between horses and personnel.

scholarly journals Comparative Genome Sequencing of an Isogenic Pair of USA800 Clinical Methicillin-Resistant Staphylococcus aureus Isolates Obtained before and after Daptomycin Treatment Failure

2011 ◽  
Vol 55 (5) ◽  
pp. 2018-2025 ◽  
Author(s):  
Susan Boyle-Vavra ◽  
Marcus Jones ◽  
Brett L. Gourley ◽  
Michael Holmes ◽  
Rebecca Ruf ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Treatment Failure ◽  
Resistant Isolate ◽  
Genome Sequences ◽  
Methicillin Resistant ◽  
Content Type ◽  
Reading Frame ◽  
Type Iv ◽  
Before And After ◽  
Positively Charged

ABSTRACTWe describe here a clinical daptomycin treatment failure in a patient with recurrent methicillin-resistantStaphylococcus aureus(MRSA) bacteremia in whom daptomycin was administered after a failed empirical treatment course with vancomycin and piperacillin-tazobactam. We had the opportunity to compare the genome sequences of an isogenic pair of daptomycin-susceptible and -resistant MRSA isolates obtained before and after initiation of daptomycin therapy, respectively. The genotype of both isolates was USA800, ST5, SCCmectype IV,agrtype II. There was no increase in cell wall thickness in the daptomycin-resistant strain despite having decreased susceptibility to both vancomycin and daptomycin. By comparing the genome sequences by pyrosequencing, we identified a polymorphism (S337L) in the tenth transmembrane segment of the multiple peptide resistance factor, MprF, encoding lysyl phosphatidylglycerol transferase. This enzyme has been shown previously to promote repulsion of daptomycin at the cell surface by addition of positively charged lysine to phosphatidylglycerol. Also, thehlbopen reading frame (ORF) encoding the β-toxin was interrupted by a prophage in the daptomycin-susceptible strain; this phage was missing in the daptomycin-resistant isolate and thehlbORF was restored. Loss of the phage in the resistant isolate also resulted in loss of the virulence factor genesclpP,scn, andsak. This is the first study to use pyrosequencing to compare the genomes of a daptomycin-susceptible/resistant MRSA isolate pair obtained during failed daptomycin therapy in humans.

scholarly journals Evaluation of Ceftaroline Alone and in Combination against Biofilm-Producing Methicillin-Resistant Staphylococcus aureus with Reduced Susceptibility to Daptomycin and Vancomycin in anIn VitroPharmacokinetic/Pharmacodynamic Model

2015 ◽  
Vol 59 (8) ◽  
pp. 4497-4503 ◽  
Author(s):  
Katie E. Barber ◽  
Jordan R. Smith ◽  
Cortney E. Ireland ◽  
Blaise R. Boles ◽  
Warren E. Rose ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Device ◽  
Bloodstream Infections ◽  
Methicillin Resistant ◽  
Content Type ◽  
Elimination Half ◽  
Antimicrobial Protection ◽  
Mrsa Strains ◽  
Post Hoc

ABSTRACTAnnually, medical device infections are associated with >250,000 catheter-associated bloodstream infections (CLABSI), with up to 25% mortality.Staphylococcus aureus, a primary pathogen in these infections, is capable of biofilm production, allowing organism persistence in harsh environments, offering antimicrobial protection. With increases inS. aureusisolates with reduced susceptibility to current agents, ceftaroline (CPT) offers a therapeutic alternative. Therefore, we evaluated whether CPT would have a role against biofilm-producing methicillin-resistantS. aureus(MRSA), including those with decreased susceptibilities to alternative agents. In this study, we investigated CPT activity alone or combined with daptomycin (DAP) or rifampin (RIF) against 3 clinical biofilm-producing MRSA strains in anin vitrobiofilm pharmacokinetic/pharmacodynamic (PK/PD) model. Simulated antimicrobial regimens were as follows: 600 mg of CPT every 8 h (q8h) (free maximum concentration of drug [fCmax], 17.04 mg/liter; elimination half-life [t1/2], 2.66 h), 12 mg/kg of body weight/day of DAP (fCmax, 14.7 mg/liter;t1/2, 8 h), and 450 mg of RIF q12h (fCmax, 3.5 mg/liter;t1/2, 3.4 h), CPT plus DAP, and CPT plus RIF. Samples were obtained and plated to determine colony counts. Differences in log10CFU/cm2were evaluated by analysis of variance with Tukey'spost hoctest. The strains were CPT and vancomycin susceptible and DAP nonsusceptible (DNS). CPT displayed activity throughout the experiment. DAP demonstrated initial activity with regrowth at 24 h in all strains. RIF was comparable to the drug-free control, and little benefit was observed when combined with CPT. CPT plus DAP displayed potent activity, with an average log10CFU/cm2reduction of 3.33 ± 1.01 from baseline. CPT demonstrated activity against biofilm-producing DNS MRSA. CPT plus DAP displayed therapeutic enhancement over monotherapy, providing a potential option for difficult-to-treat medical device infections.

scholarly journals Novel Type of Staphylococcal Cassette Chromosome mec Identified in Community-Acquired Methicillin-Resistant Staphylococcus aureus Strains

2002 ◽  
Vol 46 (4) ◽  
pp. 1147-1152 ◽  
Author(s):  
Xiao Xue Ma ◽  
Teruyo Ito ◽  
Chuntima Tiensasitorn ◽  
Mantana Jamklang ◽  
Piriyaporn Chongtrakool ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance Genes ◽  
Gene Complex ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Class B ◽  
New Type ◽  
Mrsa Strains ◽  
Hospital Acquired ◽  
Staphylococcal Cassette Chromosome

ABSTRACT We identified a new type of staphylococcal cassette chromosome mec (SCCmec) from two community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strains. The novel element, designated type IV SCCmec, had a unique combination of the class B mec gene complex and the type 2 ccr gene complex and was much smaller in size (21 to 24 kb) than previously identified SCCmec elements of hospital-acquired MRSA. Consistent with the strains' susceptibilities to various non-β-lactam antibiotics, the type IV SCCmec was devoid of any antibiotic resistance genes other than the mecA gene.

scholarly journals Daptomycin plus Fosfomycin, a Synergistic Combination in Experimental Implant-Associated Osteomyelitis Due to Methicillin-Resistant Staphylococcus aureus in Rats

2014 ◽  
Vol 59 (2) ◽  
pp. 859-863 ◽  
Author(s):  
Tilman Lingscheid ◽  
Wolfgang Poeppl ◽  
Dominik Bernitzky ◽  
Luzia Veletzky ◽  
Manuel Kussmann ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Once Daily ◽  
Methicillin Resistant ◽  
Bacterial Counts ◽  
Content Type ◽  
Bacterial Cultures ◽  
Development Of Resistance ◽  
Bacterial Inoculum ◽  
Titanium Wire ◽  
Mrsa Infection

ABSTRACTThe aim of this study was to evaluate the combination of daptomycin and fosfomycin in experimental chronic implant-associated osteomyelitis due to methicillin-resistantStaphylococcus aureus(MRSA). Infection was induced in the tibiae of rats by the insertion of a bacterial inoculum (1 to 5 × 108CFU/ml) of a clinical MRSA isolate and a titanium wire. Four weeks after infection, each animal was assigned to a treatment group: daptomycin monotherapy at 60 mg/kg of body weight once daily (n= 10), fosfomycin monotherapy at 40 mg/kg once daily (n= 10), or daptomycin and fosfomycin combined at 60 mg/kg and 40 mg/kg, respectively, once daily (n= 9). Ten animals were left untreated. After a 3-week treatment period, the animals were euthanized, and the infected tibiae and implants were processed for quantitative bacterial cultures. The bacterial cultures from bones were positive for MRSA in all animals in the untreated group, the daptomycin group, and the fosfomycin group, with median bacterial counts of 2.34 × 106CFU/g bone, 1.57 × 106CFU/g bone, and 3.48 × 102CFU/g bone, respectively. In the daptomycin-fosfomycin group, 6 out of 9 animals were positive for MRSA, with a median count of 7.92 CFU/g bone. Bacterial cultures derived from the titanium wires were negative in the fosfomycin- and daptomycin-fosfomycin-treated groups. Based on bacterial counts in bones, treatment with daptomycin-fosfomycin was statistically significantly superior to all that of the other groups (P≤ 0.003). Fosfomycin was superior to daptomycin and no treatment (P< 0.0001). No development of resistance was observed in any treatment arm. The combination of daptomycin and fosfomycin demonstrated synergism against MRSA in experimental implant-associated osteomyelitis.

scholarly journals In VitroPharmacodynamics of Human Simulated Exposures of Ceftaroline and Daptomycin against MRSA, hVISA, and VISA with and without Prior Vancomycin Exposure

2013 ◽  
Vol 58 (2) ◽  
pp. 672-677 ◽  
Author(s):  
Amira A. Bhalodi ◽  
Mao Hagihara ◽  
David P. Nicolau ◽  
Joseph L. Kuti
Keyword(s):  
Staphylococcus Aureus ◽  
Body Weight ◽  
Sequential Therapy ◽  
Free Drug ◽  
Pharmacodynamic Model ◽  
Prior Exposure ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Infection

ABSTRACTThe effects of prior vancomycin exposure on ceftaroline and daptomycin therapy against methicillin-resistantStaphylococcus aureus(MRSA) have not been widely studied. Humanized free-drug exposures of vancomycin at 1 g every 12 h (q12h), ceftaroline at 600 mg q12h, and daptomycin at 10 mg/kg of body weight q24h were simulated in a 96-hin vitropharmacodynamic model against three MRSA isolates, including one heteroresistant vancomycin-intermediateS. aureus(hVISA) isolate and one VISA isolate. A total of five regimens were tested: vancomycin, ceftaroline, and daptomycin alone for the entire 96 h, and then sequential therapy with vancomycin for 48 h followed by ceftaroline or daptomycin for 48 h. Microbiological responses were measured by the changes in log10CFU during 96 h from baseline. Control isolates grew to 9.16 ± 0.32, 9.13 ± 0.14, and 8.69 ± 0.28 log10CFU for MRSA, hVISA, and VISA, respectively. Vancomycin initially achieved ≥3 log10CFU reductions against the MRSA and hVISA isolates, followed by regrowth beginning at 48 h; minimal activity was observed against VISA. The change in 96-h log10CFU was largest for sequential therapy with vancomycin followed by ceftaroline (−5.22 ± 1.2,P= 0.010 versus ceftaroline) and for sequential therapy with vancomycin followed by ceftaroline (−3.60 ± 0.6,P= 0.037 versus daptomycin), compared with daptomycin (−2.24 ± 1.0), vancomycin (−1.40 ± 1.8), and sequential therapy with vancomycin followed by daptomycin (−1.32 ± 1.0,P> 0.5 for the last three regimens). Prior exposure of vancomycin at 1 g q12h reduced the initial microbiological response of daptomycin, particularly for hVISA and VISA isolates, but did not affect the response of ceftaroline. In the scenario of poor vancomycin response for high-inoculum MRSA infection, a ceftaroline-containing regimen may be preferred.

scholarly journals Activities of Oxadiazole Antibacterials against Staphylococcus aureus and Other Gram-Positive Bacteria

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Sara Ceballos ◽  
Choon Kim ◽  
Derong Ding ◽  
Shahriar Mobashery ◽  
Mayland Chang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Mrsa Strains

ABSTRACT The activities of four oxadiazoles were investigated with 210 methicillin-resistant Staphylococcus aureus (MRSA) strains. MIC50 and MIC90 values of 1 to 2 and 4 μg/ml, respectively, were observed. We also evaluated the activity of oxadiazole ND-421 against other staphylococci and enterococci and in the presence of oxacillin for selected MRSA strains. The MIC for ND-421 is lowered severalfold in combination with oxacillin, as they synergize. The MIC90 of ND-421 against vancomycin-resistant enterococci is ≤1 μg/ml.

scholarly journals Differentiation of Community-Associated and Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates and Identification of spa Types by Use of PCR and High-Resolution Melt Curve Analysis

2020 ◽  
Vol 58 (5) ◽  
Author(s):  
Seyed A. Ghorashi ◽  
Jane Heller ◽  
Quincy Zhang ◽  
Shafi Sahibzada
Keyword(s):  
Staphylococcus Aureus ◽  
High Resolution ◽  
Curve Analysis ◽  
Health Concern ◽  
Staphylococcal Protein A ◽  
Visual Interpretation ◽  
High Resolution Melt ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains

ABSTRACT Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are present worldwide and represent a major public health concern. The capability of PCR followed by high-resolution melt (HRM) curve analysis for the detection of community-associated and livestock-associated MRSA strains and the identification of staphylococcal protein A (spa) locus was evaluated in 74 MRSA samples which were isolated from the environment, humans, and pigs on a single piggery. PCR-HRM curve analysis identified four spa types among MRSA samples and differentiated MRSA strains accordingly. A nonsubjective differentiation model was developed according to genetic confidence percentage values produced by tested samples, which did not require visual interpretation of HRM curve results. The test was carried out at different settings, and result data were reanalyzed and confirmed with DNA sequencing. PCR-HRM curve analysis proved to be a robust and reliable test for spa typing and can be used as a tool in epidemiological studies.

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