Heather O'Connell

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Indirect pathogenicity (IP), the commensal protection of antibiotic-sensitive pathogens by resistant microorganisms of low intrinsic virulence, can prevent the eradication of polymicrobial infections. The contributions of antibiotic resistance mechanisms and biofilm structure to IP within polymicrobial biofilms were investigated using a model two-member(More)
BACKGROUND In January 2012, on the basis of an initial report from a dermatologist, we began to investigate an outbreak of tattoo-associated Mycobacterium chelonae skin and soft-tissue infections in Rochester, New York. The main goals were to identify the extent, cause, and form of transmission of the outbreak and to prevent further cases of infection. (More)
BACKGROUND Mucormycosis is an invasive fungal infection with a high fatality rate. We investigated an outbreak of mucormycosis in a pediatric hospital to determine routes of pathogen transmission from the environment and prevent additional infections. METHODS A case was defined as a hospital-onset illness consistent with mucormycosis, confirmed by culture(More)
Escherichia coli has been widely used for heterologous protein production (HPP). To determine whether a biofilm environment could benefit E. coli HPP using high copy number plasmids, we compared plasmid maintenance and HPP by E. coli ATCC 33456 containing plasmid pEGFP (a pUC family vector) cultivated in biofilms and in suspended culture. Cells were grown(More)
Twelve Laboratory Response Network (LRN) affiliated laboratories participated in a validation study of a macrofoam swab protocol for the recovery, detection, and quantification of viable B. anthracis (BA) Sterne spores from steel surfaces. CDC personnel inoculated steel coupons (26cm(2)) with 1-4 log(10) BA spores and recovered them by sampling with(More)
AIMS To evaluate the efficacy of chlorine dioxide (ClO(2)) against seven species of bacterial threat (BT) agents in water. METHODS AND RESULTS Two strains of Bacillus anthracis spores, Yersinia pestis, Francisella tularensis, Burkholderia pseudomallei, Burkholderia mallei and Brucella species were each inoculated into a ClO(2) solution with an initial(More)
AIMS To determine the range of free available chlorine (FAC) required for disinfection of the live vaccine strain (LVS) and wild-type strains of Francisella tularensis. METHODS AND RESULTS Seven strains of planktonic F. tularensis were exposed to 0·5 mg·l(-1) FAC for two pH values, 7 and 8, at 5 and 25°C. LVS was inactivated 2 to 4 times more quickly than(More)
This work was initiated to address the gaps identified by Congress regarding validated biothreat environmental sampling and processing methods. Nine Laboratory Response Network-affiliated laboratories participated in a validation study of a cellulose sponge wipe-processing protocol for the recovery, detection, and quantification of viable Bacillus anthracis(More)
Multi-resolution image clustering and segmentation interactive system has been developed to analyze the interaction between clusters of heterogeneous microbial populations residing in biofilms. Biofilms are biological microorganisms attached to surfaces, which develop a complex heterogeneous three-dimensional structure. The hierarchical structural analysis(More)
Seven species of bacterial biothreat agents were tested for susceptibility to UV light (254 nm). All gram-negative organisms tested required <12 mJ/cm(2) for a 4-log(10) reduction in viability (inactivation). Tailing off of the B. anthracis spore inactivation curves began close to the 2-log(10) inactivation point, with a fluence of approximately 40(More)