Tetrasodium EDTA as a novel central venous catheter lock solution against biofilm.

BACKGROUND: Central venous catheter (CVC)-related bloodstream infections (BSIs) are known to increase rates of morbidity and mortality in both inpatients and outpatients, including hematology-oncology patients and those undergoing hemodialysis or home infusion therapy. Biofilm-associated organisms on the lumens of these catheters have reduced susceptibility to antimicrobial chemotherapy. This study tested the efficacy of tetrasodium EDTA as a catheter lock solution on biofilms of several clinically relevant microorganisms. METHODS: Biofilms of Staphylococcus epidermidis, methicillin-resistant S. aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Candida albicans were grown to levels of approximately 1 x 10(5) colony-forming units (CFU)/cm(-1) on CVC segments in a model system, then subjected to the tetrasodium EDTA lock treatment. RESULTS: Comparisons of biofilms before and after exposure to the 40-mg/mL(-1) tetrasodium EDTA lock for 21 hours showed that the biofilm viable cell counts of all organisms tested were significantly reduced (P < .05) after exposure to the treatment. CONCLUSION: Antimicrobial lock treatment using 40 mg/mL(-1) of tetrasodium EDTA for at least 21 hours could significantly reduce or potentially eradicate CVC-associated biofilms of clinically relevant microorganisms.

High quality draft genome sequence of Segniliparus rugosus CDC 945(T)= (ATCC BAA-974(T)).

Segniliparus rugosus represents one of two species in the genus Segniliparus, the sole genus in the family Segniliparaceae. A unique and interesting feature of this family is the presence of extremely long carbon-chain length mycolic acids bound in the cell wall. S. rugosus is also a medically important species because it is an opportunistic pathogen associated with mammalian lung disease. This report represents the second species in the genus to have its genome sequenced. The 3,567,567 bp long genome with 3,516 protein-coding and 49 RNA genes is part of the NIH Roadmap for Medical Research, Human Microbiome Project.

Aspergillus terreus accessory conidia are unique in surface architecture, cell wall composition and germination kinetics.

Infection with Aspergillus terreus is more likely to result in invasive, disseminated disease when compared to other Aspergillus species; importantly this species appears to be less susceptible to the antifungal drug amphotericin B. Unique to this species is the ability to produce specialized structures denoted as accessory conidia (AC) directly on hyphae both in vitro and in vivo. With the hypothesis that production of AC by A. terreus may enhance virulence of this organism, we analyzed the phenotype, structure and metabolic potential of these conidia. Comparison of A. terreus phialidic conidia (conidia that arise from conidiophores, PC) and AC architecture by electron microscopy revealed distinct morphological differences between the two conidial forms; AC have a smoother, thicker outer cell surface with no apparent pigment-like layer. Further, AC germinated rapidly, had enhanced adherence to microspheres, and were metabolically more active compared to PC. Additionally, AC contained less cell membrane ergosterol, which correlated with decreased susceptibility to AMB as determined using a flow cytometry based analysis. Furthermore, AC exhibited surface patches of beta1-3 glucan, suggestive of attachment scarring. Collectively, the findings of this study suggest a possible role for AC in A. terreus pathogenesis.

Novel mycolic acid-containing bacteria in the family Segniliparaceae fam. nov., including the genus Segniliparus gen. nov., with descriptions of Segniliparus rotundus sp. nov. and Segniliparus rugosus sp. nov.

Four strains of novel, rapidly growing, acid-alcohol-fast-staining bacteria were characterized with a polyphasic approach. Isolates were received by the Centers for Disease Control and Prevention from domestic health department laboratories for reference testing as unidentifiable, clinical mycobacteria. Bacteria were rod-shaped and produced non-pigmented (white to beige), non-photochromogenic, smooth or wrinkled-rough colonies on Middlebrook 7H10 and 7H11 media at 33 degrees C. The smooth and wrinkled colony forms were representative of two species with 68.0 and 72.0 mol% DNA G+C content. The cell wall contained meso-diaminopimelic acid and mycolic acids. Species were characterized by cellular fatty acids of C10:0, C14:0, C16:1omega9t, C16:0, C18:1omega9c and 10-methyl C18:0 (tuberculostearic acid). HPLC analysis of mycolic acids produced a novel late-emerging, genus-specific mycolate pattern. TLC analysis demonstrated a novel alpha(+)-mycolate. Species were 98.9% similar by comparison of 16S rRNA gene sequences; however, the DNA-DNA association was <28 %. Phylogenetic analysis of 16S rRNA gene sequences demonstrated an association with Rhodococcus equi, although a DNA-DNA relatedness value of 2% did not support a close relationship. PCR analysis of a proposed, selected actinomycete-specific 439 bp fragment of the 65 kDa heat-shock protein was negative for three of the four isolates. The creation of Segniliparaceae fam. nov. is proposed to encompass the genus Segniliparus gen. nov., including two novel species, the type species Segniliparus rotundus sp. nov. and Segniliparus rugosus sp. nov., with the respective type strains CDC 1076(T) (=ATCC BAA-972(T)=CIP 108378(T)) and CDC 945(T) (=ATCC BAA-974(T)=CIP 108380(T)).

An outbreak of neonatal deaths in Brazil associated with contaminated intravenous fluids.

A nursery outbreak of fever and clinical sepsis resulted in the deaths of 36 neonates in Roraima, Brazil. To determine the cause, epidemiologic studies were performed, along with culture and endotoxin analysis of intravenous (iv) fluids. Affected neonates were more likely to have lower birth weight (2.1 vs. 3.2 kg; P<.01), lower APGAR (activity, pulse, grimace, appearance, and respiration) score at 1 (7 vs. 8; P=.1) or 5 min (8 vs. 9; P=.03), lower gestational age (32 vs. 39 weeks; P=.001), or to receive iv medications (20/20 vs. 2/40; P<.0001). Fever occurred only after iv medication administration. Although culture results of unopened iv medications were negative, endotoxin levels of glucose and distilled water for injection were elevated (3.3 and 1.2 U/mL, respectively). Endotoxin-contaminated iv medications were distributed nationally and may have caused other outbreaks of unexplained death. These results highlight the importance of monitoring both pharmaceutical quality and postmarketing surveillance for adverse events.