No abstract

A synthetic polyamino polymer with a glucose backbone was used for gene transfer in vitro and in vivo. Gene transfer in vitro to various human carcinoma cell lines was achieved with an efficiency superior to a commercially available cationic liposome preparation. The polymer was resistant to inhibition by serum, which allowed for efficient gene transfer in vivo. Direct Intracranial tumor injection using this reagent resulted in reporter gene expression levels comparable to those achieved by a recombinant adenoviral vector. Thus, this compound represents a new class of agent that may have broad utility for gene transfer and gene therapy applications.

Extended spectrum beta-lactamase (ESBL)- or AmpC beta-lactamase (ACBL)- producing Escherichia coli are the most common cause of community-acquired multidrug resistant urinary tract infections (UTIs) in New Zealand. The carriage of antimicrobial resistant bacteria has been found in both people and pets from the same household; thus, the home environment may be a place where antimicrobial resistant bacteria are shared between humans and pets. In this study we sought to determine whether household members (pets and people), from households of human index cases with a UTI caused by an ESBL- or ACBL- producing E. coli strain, also carried an ESBL- or ACBL- producing Enterobacteriaceae strain and if so, whether it was a clonal match to the index case clinical strain. Index cases with a community-acquired UTI were recruited based on antimicrobial susceptibility testing of urine isolates. Fecal samples were collected from 18 non-index people and 36 pets across 27 households. Eleven of the 27 households screened had non-index household members (8/18 people and 5/36 animals) positive for ESBL- and/or ACBL- E. coli. Whole-genome sequence analysis of 125 E. coli isolates (including the clinical urine isolate) from these 11 households showed that within seven households the same strain of ESBL-/ACBL- producing E. coli was cultured, from both the index case and another person (5/11 households) or pet dog (2/11 households). These results suggest that transmission within the household may contribute to community spread of ESBL- or ACBL- producing E. coli. IMPORTANCE Enterobacteriaceae that produce extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamases (ACBL) are important pathogens and can cause community-acquired illnesses such as urinary tract infections (UTIs). Fecal carriage of these resistant bacteria by companion animals may pose a risk for transmission to humans. Our work evaluated the sharing of ESBL- and ACBL- producing E. coli between humans and companion animals. We found that in some households, dogs carried the same strain of ESBL producing E. coli as the household member with a UTI. This suggests that transmission events between humans and animals (or vice versa) are likely to be occurring within the home environment and therefore the community as a whole. This is significant from a health perspective when considering measures to minimize community transmission and highlights that in order to manage community spread, we need to consider interventions at the household level.

Aims:  To examine the rate and the extent of spore formation in Anoxybacillus flavithermus biofilms and to test the effect of one key variable – temperature – on spore formation. Methods and Results:  A continuous flow laboratory reactor was used to grow biofilms of the typical dairy thermophile A. flavithermus (strain CM) in skim milk. The reactor was inoculated with either a washed culture or a spore suspension of A. flavithermus CM, and was run over an 8·5 h period at three different temperatures of 48, 55 and 60°C. Change in impedance was used to determine the cell numbers in the milk and on the surface of the stainless steel reactor tubes. The biofilm developed at all three temperatures within 6–8 h. Spores formed at 55 and 60°C and amounted to approx. 10–50% of the biofilm. No spores formed at 48°C. Conclusions:  The results suggest that both biofilm formation and spore formation of A. flavithermus can occur very rapidly and simultaneously. In addition, temperature variation has a considerable effect on the formation of spores. Significance and Impact of the Study:  This information will provide direction for developing improved ways in which to manipulate conditions in milk powder manufacturing plants to control biofilms and spores of A. flavithermus.