Pneumococcal Serotypes before and after Introduction of Conjugate Vaccines, United States, 1999–2011

Serotyping data for pneumococci causing invasive and noninvasive disease in 2008–2009 and 2010–2011 from >43 US centers were compared with data from preconjugate vaccine (1999–2000) and postconjugate vaccine (2004–2005) periods. Prevalence of 7-valent pneumococcal conjugate vaccine serotypes decreased from 64% of invasive and 50% of noninvasive isolates in 1999–2000 to 3.8% and 4.2%, respectively, in 2010–2011. Increases in serotype 19A stopped after introduction of 13-valent pneumococcal vaccine (PCV13) in 2010. Prevalences of other predominant serotypes included in or related to PCV13 (3, 6C, 7F) also remained similar for 2008–2009 and 2010–2011. The only major serotype that increased from 2008–2009 to 2010–2011 was nonvaccine serotype 35B. These data show that introduction of the 7-valent vaccine has dramatically decreased prevalence of its serotypes and that addition of serotypes in PCV13 could provide coverage of 39% of isolates that continue to cause disease

Redefining the Chronic-Wound Microbiome: Fungal Communities Are Prevalent, Dynamic, and Associated with Delayed Healing

Chronic nonhealing wounds have been heralded as a silent epidemic, causing significant morbidity and mortality especially in elderly, diabetic, and obese populations. Polymicrobial biofilms in the wound bed are hypothesized to disrupt the highly coordinated and sequential events of cutaneous healing. Both culture-dependent and -independent studies of the chronic-wound microbiome have almost exclusively focused on bacteria, omitting what we hypothesize are important fungal contributions to impaired healing and the development of complications. Here we show for the first time that fungal communities (the mycobiome) in chronic wounds are predictive of healing time, associated with poor outcomes, and form mixed fungal-bacterial biofilms. We longitudinally profiled 100, nonhealing diabetic-foot ulcers with high-throughput sequencing of the pan-fungal internal transcribed spacer 1 (ITS1) locus, estimating that up to 80% of wounds contain fungi, whereas cultures performed in parallel captured only 5% of colonized wounds. The “mycobiome” was highly heterogeneous over time and between subjects. Fungal diversity increased with antibiotic administration and onset of a clinical complication. The proportions of the phylum Ascomycota were significantly greater (P = 0.015) at the beginning of the study in wounds that took >8 weeks to heal. Wound necrosis was distinctly associated with pathogenic fungal species, while taxa identified as allergenic filamentous fungi were associated with low levels of systemic inflammation. Directed culturing of wounds stably colonized by pathogens revealed that interkingdom biofilms formed between yeasts and coisolated bacteria. Combined, our analyses provide enhanced resolution of the mycobiome during impaired wound healing, its role in chronic disease, and impact on clinical outcomes

Accuracy of Phenotypic Methods for Identification of Streptococcus pneumoniae Isolates Included in Surveillance Programs▿

Similarities between Streptococcus pneumoniae and viridans group streptococci may result in misidentification of these organisms. In surveillance programs which assess antimicrobial resistance rates among respiratory tract pathogens, such identification errors could lead to overestimates of pneumococcal resistance rates. DNA probe analysis (Gen-Probe, San Diego, CA), the bile solubility test, optochin susceptibility, colony morphology, and the capsular swelling reaction with Omni serum (Staten Serum Institut, Copenhagen, Denmark) were used to characterize 1,733 organisms provisionally identified as S. pneumoniae in a 2004 to 2005 antimicrobial resistance surveillance program. These organisms were obtained in 41 U.S. medical centers. Among these, 1,647 (95%) were determined to be S. pneumoniae by DNA probe. Elimination of those isolates found not to be S. pneumoniae resulted in 1 to 2% decreases in resistance rate estimates with penicillin, erythromycin, tetracycline, and trimethoprim-sulfamethoxazole. With AccuProbe as a reference standard, the sensitivities and specificities of each phenotypic method for the identification of S. pneumoniae were, respectively, 98.8% and 82.6% for bile solubility, 99.3% and 74.4% for the capsular swelling reaction with Omni serum, and 87.9% and 59.3% for optochin susceptibility. Colony morphology was of limited value, as 391 (23.7%) isolates lacked the typical button or mucoid colony appearance of S. pneumoniae

Castanea sativa (European Chestnut) Leaf Extracts Rich in Ursene and Oleanene Derivatives Block Staphylococcus aureus Virulence and Pathogenesis without Detectable Resistance.

The Mediterranean is home to a rich history of medical traditions that have developed under the influence of diverse cultures over millennia. Today, many such traditions are still alive in the folk medical practices of local people. Investigation of botanical folk medicines used in the treatment of skin and soft tissue infections led us to study Castanea sativa (European Chestnut) for its potential antibacterial activity. Here, we report the quorum sensing inhibitory activity of refined and chemically characterized European Chestnut leaf extracts, rich in oleanene and ursene derivatives (pentacyclic triterpenes), against all Staphylococcus aureus accessory gene regulator (agr) alleles. We present layers of evidence of agr blocking activity (IC50 1.56-25 μg mL-1), as measured in toxin outputs, reporter assays hemolytic activity, cytotoxicity studies, and an in vivo abscess model. We demonstrate the extract's lack of cytotoxicity to human keratinocytes and murine skin, as well as lack of growth inhibitory activity against S. aureus and a panel of skin commensals. Lastly, we demonstrate that serial passaging of the extract does not result in acquisition of resistance to the quorum quenching composition. In conclusion, through disruption of quorum sensing in the absence of growth inhibition, this study provides insight into the role that non-biocide inhibitors of virulence may play in future antibiotic therapies

BD Phoenix and Vitek 2 Detection of mecA-Mediated Resistance in Staphylococcus aureus with Cefoxitin▿

The BD Phoenix (BD Diagnostics, Sparks, MD) and Vitek 2 (bioMérieux, Durham, NC) automated susceptibility testing systems have implemented the use of cefoxitin to enhance the detection of methicillin (meticillin)-resistant Staphylococcus aureus (MRSA). To assess the impact of this change, 620 clinically significant S. aureus isolates were tested in parallel on Phoenix PMIC/ID-102 panels and Vitek 2 AST-GP66 cards. The results for oxacillin and cefoxitin generated by the automated systems were compared to those generated by two reference methods: mecA gene detection and MICs of oxacillin previously determined by broth microdilution according to CLSI guidelines. Testing of isolates with discordant results was repeated to attain a majority or consensus final result. There was 100% final agreement between the results of the two reference methods. For the 448 MRSA and 172 methicillin-susceptible S. aureus isolates tested, the rates of categorical agreement of the results obtained with the automated systems with those obtained by the reference methods were 99.8% for the Phoenix panels and 99.7% for the Vitek 2 cards. A single very major error occurred on each instrument (0.2%) with different MRSA isolates. The only major error was attributed to the Vitek 2 system overcalling oxacillin resistance. In 16 instances (9 on the Phoenix system, 7 on the Vitek 2 system), an oxacillin MIC in the susceptible range was correctly changed to resistant by the expert system on the basis of the cefoxitin result. The inclusion of cefoxitin in the Phoenix and Vitek 2 panels has optimized the detection of MRSA by both systems

Putative structures of compounds other than pentacyclic triterpenes found in the most active region of 224C-F2 (retention time of 21–49 min).

<p>Compounds are listed by Peak number, corresponding to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136486#pone.0136486.t005" target="_blank">Table 5</a>. Peak <b>32</b> was determined to be C₃₅H₅₉O₆ with a relative abundance of 0.30%. Putative structural matches include: (<b>32a</b>) stigmastane and (<b>32b</b>) (3β, 4β, 16α, 21β, 22α) -16, 21, 22, 23, 28- pentamethoxy (9CI) olean- 12- en- 3- ol (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136486#pone.0136486.g010" target="_blank">Fig 10</a>). Peak <b>33</b> was determined to be C₂₇H₂₃O₁₈ with a relative abundance of 0.16%. Putative structural matches include: (<b>33a</b>) 1,3,6-tri-O-galloylglucose; (<b>33b</b>) 1,2,6-tri-galloyl-β-D-glucose; (<b>33c</b>) 1,2,3-tri-O-galloylglucose; (<b>33d</b>) 1,2,3-tri-O-galloyl-β-D-glucopyranose; (<b>33e</b>) 2',3,5-tri-O-galloyl-D-hamamelose; (<b>33f</b>) 2- <i>C</i>- [[(3, 4, 5- trihydroxybenzoyl) oxy] methyl]- 1, 5- bis(3, 4, 5- trihydroxybenzoate) D- Ribofuranose; (<b>33g</b>) kurigalin; (<b>33h</b>) 3,4,6-tri-O-galloyl-D-glucose. Peak <b>34</b> was determined to be C₃₉H₃₁O₁₅ with a relative abundance of 0.65%. Putative structural matches include: (<b>34</b>) castanoside B. Peak <b>39</b> was determined to be C₁₇H₁₁O₈ or C₂₀H₁₁O₄N₂ with a relative abundance of 0.72%. Putative structural matches include: (<b>39a</b>) 3,4,3'-tri-O-methylellagic acid and (<b>39b</b>) 3,3',4'-tri-O-methylellagic acid. Peak <b>44</b> was determined to be C₃₄H₂₉O₁₅ with a relative abundance of 0.26%. Putative structural matches included (<b>44</b>) norbadione A.</p