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Higher education has defined merit largely in terms of speed. It rewards not those who learn the most or the best, but those who report their learning back by the deadline, whether that's the time limit for the test or the end of the semester. Resilient learning takes time. More time spent in study results in longer retention, and elapsed time between reinforcements stabilizes learning. The emphasis on speed leads to less retention and less substantive performance. And because different students learn at different rates, inflexible time limits waste time for some while imposing failure on others. Extended time for learning and alternatives to the conventional term could increase the success rates of many students, especially those most disadvantaged by conventional practices.

Synbiotics are mixtures of prebiotics and probiotics that enhance the activity of probiotic bacteria when co-administered to provide greater benefits to the host. Traditionally, the synbiotics that have been discovered enhance gut probiotic strains and are nutritionally complex molecules that survive digestive breakdown until they reach the later stages of the intestinal tract. Here, we screened and identified sugars or sugar substitutes as synbiotics for the oral probiotic strains Streptococcus salivarius BLIS K12 and BLIS M18. Using a modified deferred antagonism assay, we found that 0.5% (w/v) galactose and 2.5% (w/v) raffinose were the best candidates for use as synbiotics with BLIS K12 and M18, as they trigger enhanced antimicrobial activity against a range of bacteria representing species from the mouth, gut, and skin. Using reverse transcriptase quantitative PCR, we found that this enhanced antimicrobial activity was caused by the upregulation of the lantibiotic genes salA, salB, and sal9 in either K12 or M18. This led to the conclusion that either 2.5% (w/v) raffinose or 0.5% (w/v) galactose, respectively, are suitable synbiotics for use in conjunction with BLIS K12 and M18 to enhance probiotic performance. [ABSTRACT FROM AUTHOR]

Faculty members who led change initiatives often express frustration at the roadblocks created by other faculty members or groups. In 2009 George Kuh and Stanley Ikenberry undertook a survey of provosts for the National Institute for Learning Outcomes Assessment to explore the state of student learning assessment. They found that "Gaining faculty involvement and support remains a major challenge..." Sixty-six percent of provosts at all institutions said more faculty engagement would be helpful, and "about four-fifths of provosts at doctoral research universities reported greater faculty engagement as their number one challenge". In order to make substantial improvements in colleges and universities, the author stresses the need to understand and address the sources of faculty resistance. He argues that it is necessary to not only design change for institutions but redesign institutions for change. (Contains 15 resources.)

Since the 1980s, advocates for change in higher education have called for double-loop learning. One of the main criticisms of the evaluation of colleges and universities was that they measured inputs rather than the outputs. Higher education now needs to apply the lessons of learning and change to campus leadership and organization.

College students have changed dramatically, and the skills needed for productive employment have changed as well. But colleges and universities have been slow to respond, often innovating in only small ways while leaving the core practices of undergraduate education the same. This article examines the barriers to transformational change in higher education in five categories: structure, information, incentives, finance, and culture. It suggests that the initial approach to overcoming these barriers involves generating better information in the form of feedback concerning student learning processes and outcomes.

The most fundamental problem of colleges is that, in some respects, the people within them don't learn very well. Most faculty, staff, and administrators in higher education genuinely believe in the importance of undergraduate learning and want to improve it. And many colleges innovate a lot, frequently in an effort to make those improvements. But in the domain of its core activities, the college doesn't learn easily. Even experts in learning can't learn in their role as agents of the college. A major part of the explanation concerning learning resides in the nature of colleges and universities as organizations. All organizations, not just educational institutions, operate using a set of tacit assumptions, often invisible even to those within them, about how people in the organization should behave. Organizational theorists Chris Argyris of Harvard University and the late Donald Schon of the Massachusetts Institute of Technology, following Ross Ashby, a pioneering theorist in cybernetics and artificial intelligence, made an important distinction between two levels of organizational learning: single-loop learning and double-loop learning. The distinction between single-loop and double-loop learning applies to much that people do in higher education. And it explains why most innovations, even those that produce unambiguously good results, fail to transform institutions: most innovations alter action strategies without moving on to make the second loop and reexamine the governing values. In this article, the author discusses double-loop learning as a possible solution to the problem of learning in higher education. (Contains 9 resources.)

Why is it so hard for colleges and universities to change? Why do even innovative institutions that invest considerable time and effort in attempts to improve performance often fall back into long-established patterns? Why is the whole of educational innovation often less than the sum of the parts? Consider three colleges and universities. Technically hypothetical, each exhibits some of the characteristics of many real institutions. All face increasing challenges that are visible in the data that they dutifully collect and report about their own operations. Each institution has been innovative in various ways in its attempts to meet these challenges. But each is hard pressed to say exactly what the results of its innovations have been. All three have a sense of standing at a crossroads, a moment of decision, but none can say very clearly where it is headed.

What are colleges for? What are they supposed to do? Are educators teaching their students how to grub for grades or how to learn in deep lasting ways? These are just some of the questions that the author attempts to explore in this article. An unbiased observer, looking at any organization, would look to its core processes, what its members do, what they get paid for, what it documents and records, and what criteria it uses for changing the way it does things. Colleges, judged by the same standards and by the evidence of their own documentation, aim to have people take classes. What are the classes for? There are a lot of potentially good answers to that question, but most undergraduate colleges do not preserve any information about those answers. What they do preserve--the almost exclusive documentation of their work that survives the class itself--is grades and transcripts. In this article, the author offers a disturbing glimpse at a superficial approach learning institutions may be fostering. He also offers a reflective assessment of a deep approach waiting to be nurtured. (Contains 8 notes.)

Students nowadays are getting mixed messages about the meaning of education. Evidence has emerged that what colleges have been saying to students were not aligned with what colleges have been doing for students. Students found that the values that seemed to drive policy shifted from department to department, course to course, term to term. As a result, a lot of students have reflexively reverted to the lowest common denominator. They have become cynical about "academic values," not because they were born cynics, but because they have suffered from whiplash after trying to keep their eyes on the "real meaning" of all this. The only policy that made sense to them was to look past it all to what was on the other side of the mixed messages: a job. In this article, the author discusses the need for colleges and universities to align their educational policies and practices to their educational goals. The author also discusses how students tend to lose what they have learned when they pursue goals that they do not consider important and valuable for their own sake. (Contains 12 notes.)

The human oral cavity contains a diversity of microbial habitats that have been adopted and adapted to as homeland by an amazingly heterogeneous population of microorganisms collectively referred to as the oral microbiota. These microbes generally co-habit in harmonious homeostasis. However, under conditions of imposed stress, as with changes to the host's physiology or nutritional status, or as a response to foreign microbial or antimicrobial incursions, some components of the oral "microbiome" (viz. the in situ microbiota) may enter a dysbiotic state. This microbiome dysbiosis can manifest in a variety of guises including streptococcal sore throats, dental caries, oral thrush, halitosis and periodontal disease. Most of the strategies currently available for the management or treatment of microbial diseases of the oral cavity focus on the repetitive "broad sweep" and short-term culling of oral microbe populations, hopefully including the perceived principal pathogens. Both physical and chemical techniques are used. However, the application of more focused approaches to the harnessing or elimination of key oral cavity pathogens is now feasible through the use of probiotic strains that are naturally adapted for oral cavity colonization and also are equipped to produce anti-competitor molecules such as the bacteriocins and bacteriocin-like inhibitory substances (viz BLIS). Some of these probiotics are capable of suppressing the proliferation of a variety of recognized microbial pathogens of the human mouth, thereby assisting with the restoration of oral microbiome homeostasis. BLIS K12 and BLIS M18, the progenitors of the BLISproducing oral probiotics, are members of the human oral cavity commensal species Streptococcus salivarius. More recently however, a number of other streptococcal and some non-streptococcal candidate oral probiotics have also been promoted. What is becoming increasingly apparent is that the future for oral probiotic applications will probably extend well beyond the attempted limitation of the direct pathological consequences of oral microbiome dysbiosis to also encompass a plethora of systemic diseases and disorders of the human host. The background to and the evolving prospects for the beneficial modulation of the oral microbiome via the application of BLIS-producing S. salivarius probiotics comprises the principal focus of the present review. [ABSTRACT FROM AUTHOR]

Strain ST182Gu, isolated from fresh guava fruit, was identified as Enterococcus casseliflavus on the basis of biochemical tests, sugar fermentation reactions (API20Strip), PCR with genus-specific primers, and 16S rRNA sequencing. This appears to be the first documentation of the presence of this species in guava. E. casseliflavus ST182Gu was shown to produce a 4.8 kDa class IIa bacteriocin, active against various lactic acid bacteria including Enterococcus spp. and Streptococcus spp., and Staphylococcus aureus, and different serotypes of Listeria spp. The activity of the peptide was reduced by treatment with 0.1 mg/mL proteolytic enzymes, but not by α-amylase, catalase, lipase, and 1% (w/v) sodium dodecyl sulphate (SDS), Tween-20, Tween-80, urea, NaCl, and EDTA. No change in activity was recorded after adjustment to pH values of between 2.0 and 12.0 for 2 h, and after treatment at 100 °C for 120 min or 121°C for 20 min, compared with non-treated antimicrobial peptide. The mode of action against representative susceptible bacteria was shown to be bactericidal and associated with cell lysis and enzyme- and DNA-leakage. These susceptible bacteria, Listeria ivanovii subsp. ivanovii ATCC 19119, Listeria monocytogenes ATCC 15313, and Enterococcus faecalis ATCC 19443 differed however in their sensitivity to bacteriocin ST182Gu (6,553,600 AU/mL, 102,400 AU/mL, and 51,200 AU/mL, respectively). No significant differences were detected in cell growth and bacteriocin production when strain ST182Gu was grown in MRS broth at 26 °C, 30 °C, and 37 °C for 24 h. Bacteriocin ST182Gu recovery from the surface of the producer cells showed different activity, dependent of the applied test organisms (3200, 800 and 400 AU/mL, evaluated versus L. ivanovii subsp. ivanovii ATCC 19119, L. monocytogenes ATCC 15313 and E. faecalis ATCC 19443, respectively), however, with proportional values with the activity recorded in cell free supernatant versus same test microorganisms. When bacteriocin ST182Gu was combined with sublethal doses of ciprofloxacin, synergistic inhibition of L. ivanovii subsp. ivanovii ATCC 19119 was demonstrated. This increase in ciprofloxacin sensitivity may be due to the dissipation of the proton gradient in the cell membrane of the target organism associated with exposure to bacteriocin ST182Gu. Apart from reducing the MIC of classical therapeutic antibiotics, bacteriocins such as ST182Gu may also play an important role in the treatment of multidrug resistant strains. [ABSTRACT FROM AUTHOR]

Probiotics developed for topical applications in humans have the potential to beneficially modulate microbial imbalances on the skin surface and thereby improve skin health. This study was conducted to determine whether topical formulations containing the human skin commensal Micrococcus luteus strain Q24 (BLIS Q24) are safe, tolerable and efficacious when used by healthy human subjects. M. luteus Q24 was assessed in vitro for haemolytic activity and its antibiotic susceptibility profile. Formulations of strain Q24 were evaluated for the preliminary safety and tolerability in healthy human participants. Forty-seven adults were randomly assigned to four single-site, single-blind randomised placebo or baseline controlled or active-controlled trials. Skin swab samples were collected for differential viable counts to monitor levels of probiotic colonisation. M. luteus Q24 was found to be non-haemolytic and susceptible to commonly used antibiotics. The M. luteus Q24 formulations were safe and tolerable and >90% of the participants reported improvements from baseline in the appearance (e.g., radiance and hydration) of their treated skin. Additionally, participants observed a reduction in pore size, skin clarity and enhanced skin softness. No adverse effects were reported. A dose-related significant increase was observed in the levels of M. luteus Q24 isolated from skin swabs of the probiotic-treated subjects. Placebo-controlled trials in human subjects involving the topical application of different doses of M. luteus Q24 formulations were supportive of the safety, tolerability and efficacy of probiotic M. luteus Q24. Self-reported skin health assessments by the subjects indicated that M. luteus Q24 has good potential as a probiotic for improving skin health quality. [ABSTRACT FROM AUTHOR]

Lantibiotics are antimicrobial peptides that have been the focus of much attention in recent years with a view to clinical, veterinary, and food applications. Although many lantibiotics are produced by food-grade bacteria or bacteria generally regarded as safe, some lantibiotics are produced by pathogens and, rather than contributing to food safety and/or health, add to the virulence potential of the producing strains. Indeed, genome sequencing has revealed the presence of genes apparently encoding a lantibiotic, designated Bsa (bacteriocin of Staphylococcus aureus), among clinical isolates of S. aureus and those associated with community-acquired methicillin-resistant S. aureus (MRSA) infections in particular. Here, we establish for the first time, through a combination of reverse genetics, mass spectrometry, and mutagenesis, that these genes encode a functional lantibiotic. We also reveal that Bsa is identical to the previously identified bacteriocin staphylococcin Au-26, produced by an S. aureus strain of vaginal origin. Our examination of MRSA isolates that produce the Panton-Valentine leukocidin demonstrates that many community-acquired S. aureus strains, and representatives of ST8 and ST80 in particular, are producers of Bsa. While possession of Bsa immunity genes does not significantly enhance resistance to the related lantibiotic gallidermin, the broad antimicrobial spectrum of Bsa strongly indicates that production of this bacteriocin confers a competitive ecological advantage on community-acquired S. aureus. doi:10.1128/JB.01375-09

Unlike the colicins, microcins and related peptide antibiotics, little is known about antibiotic proteins ([M.sub.r]> 10 000) from Gram-positive bacteria, since only few examples have been described to date. In this study we used heterologous expression of recombinant proteins to access the 17 kDa antibiotic protein SA-M57 from Streptococcus pyogenes, along with two proteins of unknown function identified in publicly available databases: EF1097 from Enterococcus faecalis and YpkK from Corynebacterium jeikeium. Here we show that all three are antibiotic proteins with different spectra of antimicrobial activity that kill sensitive bacteria at nanomolar concentrations. In silico structure predictions indicate that although the three proteins share little sequence similarity, they may be composed of conserved secondary structural elements: a relatively unstructured, acidic N-terminal portion and a basic C-terminal portion characterized by two helical elements separated by a loop structure and stabilized by an essential disulphide. Expression of individual segments as well as protein chimaeras revealed that, at least in the case of YpkK, the C-terminal portion is responsible for the killing action of the protein, whereas the role of the N-terminal portion remains unclear. Both scnM57 and ef1097 appear to be widely distributed in Strep. pyogenes and Ent. faecalis (respectively), whereas ypkK is found only rarely amongst clinical isolates of C. jeikeium. Finally, we determined that the proteins kill sensitive bacteria without lysis, a feature that distinguishes them from known murolytic proteins.

Streptococcus uberis is commonly found in the environment and in association with various bovine body sites and is a major cause of bovine mastitis. Moreover, S. uberis is known to produce a variety of bacteriocin-like inhibitory substances, antimicrobial agents that generally inhibit closely related bacterial species. In this respect, S. uberis strain 42 has previously been shown to produce a novel nisin variant named nisin U. This paper reports that, in addition to nisin U, S. uberis strain 42 produces a second bacteriocin that induces the lysis of metabolically active, susceptible target bacteria and which has therefore been named uberolysin. Isolation of the native active antimicrobial agent revealed that uberolysin is a 7048 Da peptide that is refractory to sequence analysis by Edman degradation. Transposon mutagenesis was used to generate a uberolysin-negative mutant of S. uberis 42 and sequencing of DNA flanking the insertion site revealed, in addition to the structural gene (ublA), several open reading frames likely to be involved in post-translational modification, transport and producer self-protection (immunity), and possibly in regulation of the biosynthetic gene cluster. In addition, a pair of direct repeats that may be involved in bacteriocin acquisition were identified; indeed, ublA could be identified in 18% of tested S. uberis strains. Enzymic hydrolysis of uberolysin was used to confirm that ublA does indeed encode the precursor of uberolysin, that an unusually short leader sequence of only six amino acids is cleaved during processing of the mature peptide and that uberolysin is post-translationally covalently modified to form a head-to-tail monocycle. Thus, uberolysin is a unique cyclic bacteriocin, belonging to the same family of bacteriocins as enterocin AS-48 and circularin A. DOI 10.1099/mic.0.2006/005967-0

Streptococcus mutans strain K8 was shown to produce a newly identified type AII lantibiotic, mutacin K8. The mutacin K8-encoding muk locus consists of 13 ORFs, three of which (mukA1, A2 and A3) have close homology to scnA, the structural gene encoding the Streptococcus pyogenes lantibiotic SA-FF22, and another (mukA') resembles scnA', an ORF in the SA-FF22 locus that has no currently assigned function. Inactivation of the muk locus indicated that mutacin K8 is responsible for most of the inhibitory activity produced by strain K8 in deferred antagonism tests on Columbia blood agar base supplemented with 5 % human blood and 0.1 % CaC[O.sub.3]. By contrast, on tryptic soy agar plus 2 % yeast extract and 0.5 % CaC[O.sub.3] most of the inhibitory activity of strain K8 appeared to be attributable either to mutacin IV or to some other inhibitory peptide(s) exported by the mutacin IV transporter nlmT. An inhibitory peptide purified from a derivative of strain K8 in which nlmT had been inactivated had a mass of 2734 Da and an N-terminal sequence identical to the predicted propeptide translation products of mukA1 and mukA3. The muk locus may be widely distributed in S. mutans, since 9 (35 %) of 26 strains tested contained at least part of the locus. In the genome sequence of strain UA159 the muk locus is incomplete, the sole residual components being the ORFs encoding the putative two-component regulatory system mukR(SMU.1815) and mukK(SMU.1814), followed by two transposases (SMU.1813 and SMU.1812) and then the ORFs mukF (SMU.1811), mukE (SMU.1810) and mukG (SMU.1809), thought to encode putative immunity peptides. Strains such as UA159 having incomplete loci did not produce detectable levels of mutacin K8.

The production of streptocins ST[H.sub.1] and ST[H.sub.2] by Streptococcus gordonii DL1 (Challis) is directly controlled by the competence regulon, which requires intact comR and comAB loci. The streptocin (sth) locus comprises two functional genes, sthA and sthB. Whereas ST[H.sub.1] activity requires sthA alone, ST[H.sub.2] activity depends on both genes.

Dysgalacticin is a novel bacteriocin produced by Streptococcus dysgalactiae subsp, equisimilis strain W2580 that has a narrow spectrum of antimicrobial activity directed primarily against the principal human streptococcal pathogen Streptococcus pyogenes. Unlike many previously described bacteriocins of Gram-positive bacteria, dysgalacticin is a heat-labile 21.5 kDa anionic protein that kills its target without inducing lysis. The N-terminal amino acid sequence of dysgalacticin [Asn-Glu-Thr-Asn-Asn-Phe-Ala-Glu-Thr-Gln -Lys-Glu-lle-Thr-Thr-Asn-(Asn)-Glu-Ala] has no known homologue in publicly available sequence databases. The dysgalacticin structural gene, dysA, is located on the indigenous plasmid pW2580 of strain W2580 and encodes a 220 aa preprotein which is probably exported via a Sec-dependent transport system. Natural dysA variants containing conservative amino acid substitutions were also detected by sequence analyses of dysA elements from S. dysgalactiae strains displaying W2580-1ike inhibitory profiles. Production of recombinant dysgalacticin by Escherichia coli confirmed that this protein is solely responsible for the inhibitory activity exhibited by strain W2580. A combination of in silico secondary structure prediction and reductive alkylation was employed to demonstrate that dysgalacticin has a novel structure containing a disulphide bond essential for its biological activity. Moreover, dysgalacticin displays similarity in predicted secondary structure (but not primary amino acid sequence or inhibitory spectrum) with another plasmid-encoded streptococcal bacteriocin, streptococcin A-M57 from S. pyogenes, indicating that dysgalacticin represents a prototype of a new class of antimicrobial proteins.

Streptococcus mutans UA159, the genome sequence reference strain, exhibits nonlantibiotic bacteriocin (mutacin) activity. In this study, we have combined bioinformatic and mutational analyses to identify the ABC transporter designated NlmTE, which is required for mutacin biogenesis in strain UAl59 as well as in another mutacin producer, S. mutans N.