Antimicrobial Resistance among Clinical Isolates of <i>Streptococcus pneumoniae</i> in the United States during 1999–2000, Including a Comparison of Resistance Rates since 1994–1995

ABSTRACT A total of 1,531 recent clinical isolates of Streptococcus pneumoniae were collected from 33 medical centers nationwide during the winter of 1999–2000 and characterized at a central laboratory. Of these isolates, 34.2% were penicillin nonsusceptible (MIC ≥ 0.12 μg/ml) and 21.5% were high-level resistant (MIC ≥ 2 μg/ml). MICs to all beta-lactam antimicrobials increased as penicillin MICs increased. Resistance rates among non-beta-lactam agents were the following: macrolides, 25.2 to 25.7%; clindamycin, 8.9%; tetracycline, 16.3%; chloramphenicol, 8.3%; and trimethoprim-sulfamethoxazole (TMP-SMX), 30.3%. Resistance to non-beta-lactam agents was higher among penicillin-resistant strains than penicillin-susceptible strains; 22.4% of S. pneumoniae were multiresistant. Resistance to vancomycin and quinupristin-dalfopristin was not detected. Resistance to rifampin was 0.1%. Testing of seven fluoroquinolones resulted in the following rank order of in vitro activity: gemifloxacin &gt; sitafloxacin &gt; moxifloxacin &gt; gatifloxacin &gt; levofloxacin = ciprofloxacin &gt; ofloxacin. For 1.4% of strains, ciprofloxacin MICs were ≥4 μg/ml. The MIC 90 s (MICs at which 90% of isolates were inhibited) of two ketolides were 0.06 μg/ml (ABT773) and 0.12 μg/ml (telithromycin). The MIC 90 of linezolid was 2 μg/ml. Overall, antimicrobial resistance was highest among middle ear fluid and sinus isolates of S. pneumoniae ; lowest resistance rates were noted with isolates from cerebrospinal fluid and blood. Resistant isolates were most often recovered from children 0 to 5 years of age and from patients in the southeastern United States. This study represents a continuation of two previous national studies, one in 1994–1995 and the other in 1997–1998. Resistance rates with S. pneumoniae have increased markedly in the United States during the past 5 years. Increases in resistance from 1994–1995 to 1999–2000 for selected antimicrobial agents were as follows: penicillin, 10.6%; erythromycin, 16.1%; tetracycline, 9.0%; TMP-SMX, 9.1%; and chloramphenicol, 4.0%, the increase in multiresistance was 13.3%. Despite awareness and prevention efforts, antimicrobial resistance with S. pneumoniae continues to increase in the United States. </jats:p

Cultures of Diabetic Foot Ulcers Without Clinical Signs of Infection Do Not Predict Outcomes

OBJECTIVE We examined associations between ulcer bioburden and ulcer outcomes in neuropathic diabetic foot ulcers (DFUs) that lacked clinical signs of infection. RESEARCH DESIGN AND METHODS Three dimensions of bioburden (i.e., microbial load, microbial diversity, and the presence of likely pathogens) were measured at baseline using swab cultures obtained by Levine’s technique. Subjects were assessed every 2 weeks for 26 weeks to determine the rate of healing and development of infection-related complications. Foot ulcers were off-loaded using total-contact casts and routinely debrided. To establish associations between bioburden and rate of healing, Cox proportional hazards and least squares regression were used after adjusting for ulcer depth, surface area, and duration. RESULTS A total of 77 subjects completed the study. Sixty-five (84.4%) had ulcers that healed during follow-up; weeks-to-closure ranged from 2 to 26 (median 4.0). Mean (± SD) percent reduction in surface area/week was 25.0% (± 23.33). Five (6.5%) of the DFUs developed an infection-related complication. None of the bioburden dimensions (i.e., microbial load, microbial diversity, or presence of likely pathogens) was significantly associated with weeks-to-closure or percent reduction in surface area per week. Weeks-to-closure was best predicted by ulcer duration, depth, and surface area (c-statistic = 0.75). CONCLUSIONS Culturing DFUs that showed no clinical signs of infection had no predictive value for outcomes of DFUs managed with total-contact casts and routine debridement. These findings support recommendations of the Infectious Disease Society of America that culturing and antibiotics should be avoided in treating DFUs that show no clinical signs of infection. </jats:sec

Schlussbericht Einzelprojekt

Mit dem Projekt LeBiAC wird die Lehrerbildung in Aachen unter den spezifischen Bedingungen der RWTH nachhaltig an die Herausforderungen der nächsten Dekade angepasst und die strategische Verankerung der Lehrerbildung an der Hochschule weiter gefestigt. Hierzu wird in der zweiten Förderphase des Projekts der schulkulturelle Wandel in einer zunehmend digitalen Welt seine umfassende Beachtung in Lehre und Forschung finden. Die angemessene Berücksichtigung digitaler Bildung in der Fortentwicklung der Lehrerbildung an der RWTH und ihre direkte Nutzbarmachung für den Umgang mit heterogenen Lerngruppen in Bildungsprozessen hat für das Projekt eine zentrale Bedeutung, weil neben der schulischen Bildung auch die Hochschullehre profitieren wird. Die Lehramtsstudiengänge übernehmen im Zuge des Projektes eine Vorreiterrolle bei der umfassenden Digitalisierung der Hochschullehre an der RWTH, was sowohl aus der Perspektive der Lehrerbildung als auch der gesamten Hochschule als bedeutsam erscheint. Im weiteren Projektverlauf werden zudem der gestärkte Praxisbezug und weitere Aspekte der Professionalisierung der Lehrerbildung konsolidiert. Dies führt zum Beispiel durch die Weiterentwicklung und nachhaltige Verankerung vielfältiger Lehr-Lern-Labore zu positiven Effekten für die regionale Einbindung der RWTH. Das Projekt LeBiAC führt ebenfalls zu einer nachhaltigen Verankerung fachdidaktischer Forschung und Nachwuchsförderung an der RWTH und stellt dauerhaft tragfähige Supportstrukturen für die Lehrerbildung bereit. Lehrerbildung wird dabei an der RWTH Aachen als Gesamtprozess von der Akquise geeigneter Studierender über deren fundierte und praxisorientierte Ausbildung bis zum Angebot der Fortbildung und Unterstützung aktiver Lehrkräfte der Region verstanden, was sich in den Zielen und Aktivitäten im LeBiAC-Projekt widerspiegelt. Dabei werden durch das Projekt auch sichtbare Impulse für eine Verbesserung der Lehrerbildung nach außen vermittelt. Datei-Upload durch TIBWith the LeBiAC project, teacher education in Aachen will be sustainably adapted to the challenges of the next decade taking into account the specific conditions of RWTH Aachen University. Teacher education is strengthened and strategically anchored at the center of university. In the second funding phase of the project, the focus in teaching and research is shifted to a changing school culture in an increasingly digital world. Teacher education is enhanced with appropriate utilization and reflection of digital education for dealing with heterogeneous learning groups. In the course of the project, courses in teacher training take on a pioneering role in the extensive digitization of higher education at RWTH Aachen University, which is groundbreaking both from the perspective of teacher training and the entire university. In the further course of the project, digitalization also plays a role in the increased practical relevance and overall professionalizing of teacher training. The RWTH teaching and learning laboratories strengthen integration of the RWTH into the regional network of schools and institutes for teacher further education. The LeBiAC project also leads to a sustainable anchoring of didactic research and the promotion of young academics at RWTH Aachen University who strengthen the structures for teacher training. Thus, the teacher education program at RWTH Aachen University implements an overall process from the acquisition of suitable students and their well-founded and practice-oriented training to offering advanced training and support of active teachers in the region, which is reflected in the goals and activities in the LeBiAC project. The project also makes teacher education visible to the scientific community and potential teachers

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

Changes in Pneumococcal Serotypes and Antimicrobial Resistance after Introduction of the 13-Valent Conjugate Vaccine in the United States

ABSTRACT Ongoing surveillance for Streptococcus pneumoniae is needed to assess the impact of the pneumococcal conjugate vaccine introduced in 2010 (PCV13). Forty-two U.S. centers submitted S. pneumoniae isolates between 1 October 2012 and 31 March 2013. Susceptibility testing was performed by use of a broth dilution method as recommended by the Clinical and Laboratory Standards Institute. Serotyping was performed by multiplex PCR and the Quellung reaction. Multidrug resistance (MDR) was defined as nonsusceptibility to penicillin (PNSP; MIC ≥ 0.12 μg/ml) combined with resistance to ≥2 non-β-lactam antimicrobials. Penicillin-resistant S. pneumoniae (PRSP) was defined as a penicillin MIC of ≥2 μg/ml. For the 1,498 isolates collected during 2012-13, the PRSP and MDR rates were 14.2 and 21.0%, respectively. These percentages were lower than rates obtained in a surveillance study conducted 4 years earlier in 2008-09 (17.0 and 26.6%, respectively). The most common serotypes identified in 2012-13 were 3, 35B, and 19A, each representing 9 to 10% of all isolates. The largest percentage of PNSP in 2012-13 were found in serotypes 35B (24.8%), 19A (23.5%), and 15A (10.3%). Predominant PRSP serotypes were 19A (54.5%), 35B (28.2%), and 19F (7.0%). Major MDR serotypes were 19A (38.5%), 15A (16.9%), 6C (8.3%), and 35B (6.4%). The change in prevalence of PCV13 serotypes (43.4 to 27.1%) was primarily due to a decrease in serotype 19A strains, i.e., 22% of all strains in 2008-09 to 10% of all strains in 2012-13. Among the PNSP subset, serotypes showing a proportional increase were 35B, 15B, and 23B. Among MDR strains, the largest proportional increases were observed in serotypes 35B, 15B, and 23A. </jats:p

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