Nasal carriage of Staphylococcus aureus: the key to preventing staphylococcal disease

Postoperative infections (Pis) are serious complications of thoracic surgery. To gain insight into the nature and the scope of the problem, an 18 month prospective surveillance was conducted at the department of thoracic surgery of the University Hospital Rotterdam, Dijkzigt. Pis were classified according to CDC criteria. One hundred and ninety-four out of 983 patients (19.7%) developed one or more Pis and in these 194 patients, 268 Pis were diagnosed. The incidence of Pis was 2.0 per 100 days of postoperative stay. The mean postoperative length of stay (LOS) of the 194 patients with Pis was 14.1 days longer than those without Pis. Deep surgical wound infections (DSWls) were associated with the longest prolongation of the median postoperative LOS in the hospital (30 days longer). Although lower than DSWls, incisional surgical wound infections also had a significant prolongation of stay (median 10 days longer). Staphylococcus aureus was the most important pathogen associated with surgical wound infections (SWls). Phage typing of 29 strains causing SWI showed only two identical pairs, so only a minority of infections could be explained by crossinfection. Older age, and more complicated procedures (e.g. cardiac valve operations) were independent, statistically significant risk factors for the development of Pis. Since there is a progressive trend towards operating on older patients and performing more complicated procedures, the incidence of Pis is expected to increase. Therefore it will become increasingly important to develop new strategies to prevent these serious complications

Kinetic Equations for Longwavelength Excitations of the Quark-Gluon Plasma

We show that longwavelength excitations of the quark-gluon plasma are described by simple kinetic equations which represent the exact equations of motion at leading order in $g$. Properties of the so-called ``hard thermal loops'', i.e. the dominant contributions to amplitudes with soft external lines, find in this approach a natural explanation. In particular, their generating functional appears here as the effective action describing long wavelength excitations of the plasma.Comment: January 8, 1993; 8 pages; SPhT/93-

Результаты изучения палеодегазации неогена и перспективы нефтегазоносности Юго-Западного Крыма

Склад флюїдів з Гераклітiв принципово не відрізняється від складу газів із сучасних зон струминного виділення в Чорному морі, що є підтвердженням їх генетичного споріднення. Дані аналізів вказують на різкі коливання змістів і непостійний склад газових флюїдів палеодегазаціі в неогені. Наявність газів вуглеводнів та слідів нафти в Гераклітах, тектонічна будова регіону дозволяють зробити висновок про високі перспективи знаходження родовищ нафти і газу в Південно-Західному Криму.The composition of fluids from Heraclitus has no fundamental differences from the gas composition from the modern jet ejections zones in the Black Sea, which is a confirmation of their genetic relatedness. Data of analysis show sharp fluctuations of the contents and unstable structure of gas fluids paleo degassing of Neogene. The presence of hydrocarbon gases and traces of oil in Heraclitus, the tectonic structure of the region allow to conclude high prospects of finding oil and gas in the South-West Crimea

From Nares to Wound: Exploring the mechanisms for Staphylococcal surgical site infections, implications for infection prevention

Surgical site infections (SSIs) are important healthcare-associated infections, leading to increased morbidity and mortality, healthcare costs, and prolonged hospital stays. Staphylococcus aureus is an important and common microbial cause of SSI. Nasal carriage of S. aureus has been shown to be an important determinant for the development of SSI, and interventions aimed at eradicating preoperative nasal carriage are associated with a reduced risk of infection. Yet, it is not entirely clear how the nasally residing S. aureus causes SSI at distant body sites. In this commentary, we describe our view on how S. aureus can be transported from the nares to the incision site during surgery. In addition, we shed light on the implications of our view for infection prevention research

The correlation between ATP measurement and microbial contamination of inanimate surfaces

Background: The objective of this study was to determine the correlation between adenosine triphosphate (ATP) measurements and microbial contamination using a standardized method. Secondarily, analyzing reproducibility of ATP measurements and aerobic colony counts (ACC’s) on the same surface. Methods: ATP measurements and ACC’s were conducted on 10 pre-defined fomites in a hospital and nursing home setting. Per fomite two ATP measurements and two agar plate measurements were conducted, each measurement was conducted on a 25 cm2 surface. Both measurements were compared and analyzed for correlation. Results: In total 200 paired measurements were conducted, 200 ATP measurements and 200 ACC’s. The mean of all ATP measurements tested on the same surface was calculated, as was for all 200 ACC’s. There was a strong correlation between the mean of two ATP measurements on two different sites on the same fomite (R = 0.800, p < 0.001) as well as between two ACC measurements on the same fomite (R = 0.667, p < 0.001). A much weaker correlation was found between RLU values and ACC’s (R = 0.244, p < 0.001). Conclusions: Reproducibility of ATP measurements and ACC’s on the same fomite was good. However, the correlation between RLU values and ACC’s on hospital surfaces was much lower. This may be explained by the wide variety of biological material that is measured with ATP, of which the bacterial load is only one of many components. ATP measurement can be used to give a quantifiable outcome for the rating of cleanliness in health care facilities, however the results cannot be translated into the level of microbial contamination

Distinguishing blaKPC -gene-containing IncF plasmids from epidemiologically related and unrelated Enterobacteriaceae based on short- and long-read sequence data

BACKGROUND: Limited information is available on whether blaKPC -containing plasmids from isolates in a hospital outbreak can be differentiated from epidemiologically unrelated blaKPC-containing plasmids based on sequence data. This study aimed to evaluate the performance of three approaches to distinguish epidemiologically related from unrelated blaKPC-containing pKpQiL-like IncFII(k2)-IncFIB(pQiL) plasmids. METHOD: Epidemiologically related isolates, were short- and long-read whole genome sequenced. A hybrid assembly was performed and plasmid sequences were extracted from the assembly graph. Epidemiologically unrelated plasmid sequences were extracted from the GenBank. Pairwise comparisons were performed of epidemiologically related and unrelated plasmids based on SNP differences using snippy, phylogenetic distance using Roary and using a similarity index that penalizes size differences between plasmids (Stoesser-index). The percentage of pairwise comparisons misclassified as genetically related or as clonally unrelated was determined using different genetic thresholds for genetic relatedness. RESULTS: The ranges in number of SNP differences, Roary phylogenetic distance, and Stoesser-index overlapped between the epidemiologically related and unrelated plasmids. When using a genetic similarity threshold that classified 100% of epidemiologically related plasmid pairs as genetically related, the percentages of plasmids misclassified as epidemiologically related ranged from 6.7% (Roary) to 20.8% (Stoesser-index). DISCUSSION: Although epidemiologically related plasmids can be distinguished from unrelated plasmids based on genetic differences, blaKPC-containing pKpQiL-like IncFII(k2)-IncFIB(pQiL) plasmids show a high degree of sequence similarity. The phylogenetic distance as determined using Roary showed the highest degree of discriminatory power between the epidemiologically related and unrelated plasmids

Development of amoxicillin resistance in Escherichia coli after exposure to remnants of a non-related phagemid-containing E. coli:an exploratory study

OBJECTIVE: To determine the effect of exposure to remnants of a phagemid-containing E. coli, killed by treatment with a propanol-based hand rub, on antimicrobial resistance in E. coli isolates. METHODS: An in vitro model was developed in which a clinical E. coli isolate (EUR1) was exposed to remnants of an E. coli K-12 strain containing a phagemid (pBS-E12) strain treated with Sterillium®. A series of 200 experiments was performed using this in vitro model. As a control, a series of 400 experiments was performed where the EUR1 was exposed either to the remnants of an E. coli K-12 strain (not containing a phagemid) (E12) treated with Sterillium® (n = 200) or to dried Sterillium® only (n = 200). The number of experiments that showed growth of an amoxicillin-resistant EUR1 isolate was evaluated in all three groups. An additional 48 experiments were performed in which a different clinical E. coli isolate (EUR2) was exposed to remnants of the pBS-E12 treated with Sterillium®. Whole-genome sequencing and phenotypic testing for AmpC beta-lactamase production was performed to investigate the mechanism behind this resistance development. RESULTS: In 22 (11.0%) of 200 experiments in which the EUR1 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained, as opposed to only 2 (1.0%) of 200 experiments involving the exposure of the EUR1 to Sterillium® only (risk difference: 10.0%; 95% CI 5.4-14.6%)) and 1 (0.5%) of 200 experiments involving the exposure of the EUR1 isolate to the remnants of the phagemid-free E12 (risk difference: 10.5%; 95% CI 6.1-14.9%). In 1 (2.1%) of the 48 experiments in which the EUR2 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained. The development of resistance in all experiments was due to mutations in the promoter/attenuator region of the chromosomal AmpC beta-lactamase (cAmpC) gene leading to cAmpC hyperproduction. CONCLUSION: Exposure of an E. coli isolate to another phagemid-containing E. coli that was treated with propanol-based hand rub increased the development of amoxicillin resistance. Although phagemids are cloning vectors that are not present in clinical isolates, this finding may have implications for hand disinfection practices in healthcare facilities