The implication of intestinal bacterial translocation in central line associated blood stream infections in the pediatric population.

INTRODUCTION: Bacterial intestinal translocation plays an important role in neonatal sepsis. We aimed to elucidate the importance of such translocation in causing central line associated blood stream infection (CLABSI) in patients undergoing gastrointestinal surgery (GIS). METHODS: Using a database of pediatric patients with CLABSI, patients were divided into those who had a GI-surgery (where intestines were opened), those who had a non-GI-surgery (NGIS; all other types of surgery) and those who had no surgery (NS). Data regarding type of organisms isolated on culture, their resistance patterns, clearance of CLABSI, type of antibiotic therapy and patient demographics were collected. RESULTS: 117 CLABSIs were identified between 2011 and 2018. 26 patients had GIS, 22 had NGIS and 69 had NS. NS patients were younger. 80% of GIS and NGIS patients had a central line at the time of surgery. Coagulase-negative staphylococcus (CoNS) was the most common organism isolated (32%). CoNS was more common in GIS compared to NGIS and NS (58% vs. 9% vs. 29% respectively, p=0.04). There were no differences in the time to resolution of bacteremia, mortality rates or need to remove the central line. CONCLUSIONS: This information should help inform efforts for prevention of CLABSIs in patients undergoing GI surgery with central lines present. LEVEL OF EVIDENCE: III.

Direct observation of dynamic mechanical regulation of DNA condensation by environmental stimuli.

Gene delivery is a promising way to treat hereditary diseases and cancer; however, there is little understanding of DNA:carrier complex mechanical properties, which may be critical for the protection and release of nucleic acids. We applied optical tweezers to directly measure single-molecule mechanical properties of DNA condensed using 19-mer poly-L-lysine (PLL) or branched histidine-lysine (HK) peptides. Force-extension profiles indicate that both carriers condense DNA actively, showing force plateaus during stretching and relaxation cycles. As the environment such as carrier concentration, pH, and the presence of zinc ions changes, DNA:HK complexes showed dynamically regulated mechanical properties at multiple force levels. The fundamental knowledge from this study can be applied to design a mechanically tailored complex which may enhance transfection efficiency by controlling the stability of the complex temporally and spatially.

The burden and severity of illness due to 2009 pandemic influenza A (H1N1) in a large US city during the late summer and early fall of 2009.

In estimates of illness severity from the spring wave of the 2009 influenza A (H1N1) pandemic, reported case fatality proportions were less than 0.05%. In prior pandemics, subsequent waves of illness were associated with higher mortality. The authors evaluated the burden of the pandemic H1N1 (pH1N1) outbreak in metropolitan Atlanta, Georgia, in the fall of 2009, when increased influenza activity heralded the second wave of the pandemic in the United States. Using data from a community survey, existing surveillance systems, public health laboratories, and local hospitals, they estimated numbers of pH1N1-associated illnesses, emergency department (ED) visits, hospitalizations, intensive care unit (ICU) admissions, and deaths occurring in metropolitan Atlanta during the period August 16, 2009-September 26, 2009. The authors estimated 132,140 pediatric and 132,110 adult symptomatic cases of pH1N1 in metropolitan Atlanta during the investigation time frame. Among children, these cases were associated with 4,560 ED visits, 190 hospitalizations, 51 ICU admissions, and 4 deaths. Among adults, they were associated with 1,130 ED visits, 590 hospitalizations, 140 ICU admissions, and 63 deaths. The combined symptomatic case hospitalization proportion, case ICU admission proportion, and case fatality proportion were 0.281%, 0.069%, and 0.024%, respectively. Influenza burden can be estimated using existing data and local surveys. The increased severity reported for subsequent waves in past pandemics was not evident in this investigation. Nevertheless, the second pH1N1 pandemic wave led to substantial numbers of ED visits, hospitalizations, and deaths in metropolitan Atlanta.