No abstract

Biofilms have been implicated in a variety of nosocomial infections associated with medical devices, hospital equipment, and other hard surfaces. In addition, household and workplace surfaces such as sinks, countertops, toilets, and cutting boards can act as reservoirs. This study's objective was to identify and evaluate literature reporting resistance to antimicrobial agents in biofilm populations. These review findings suggest that the research evaluating resistance in biofilms could be grouped into the following three mechanisms: (1) physicochemical barriers; (2) biological factors; and (3) phenotypic changes. Current research has identified potential mechanisms of antimicrobial resistance, but there is no clear evidence supporting any one mechanism. Moreover, no reported studies examine the potential impact of biofilms on biosafety practices and the public health risk of infectious diseases from biofilms in healthcare facilities and the workplace environment. Future research directions in biofilms are likely to focus on: (a) imaging of biofilms in situ, (b) in vitro and in vivo models of biofilms, (c) genetic, metabolic, and immunologic probes for real-time analysis, (d) antimicrobial resistance in multispecies biofilms, and (e) identification and characterization of phenotypic modifications. In our assessment, these studies will provide the basis to develop guidelines for biofilm-related biosafety and public health risk assessment. Applied Biosafety, 10(2) pp. 83-90

In the United States, the use and disposal of biosolids are regulated under 40 CFR part 503. Subpart D of this regulation protects public health and the environment through requirements designed to reduce the potential for contact with pathogens in biosolids applied to land or placed in a surface disposal site. For Class A biosolids, the 503 regulations require evaluation of either fecal coliforms or Salmonella, and may include enumeration of enteric viruses, or viable helminth ova. In order to demonstrate compliance, precise measurement of microbial contaminants is a necessity. However, interlaboratory comparisons of standard protocols were not available when the 503 regulations were promulgated. or relative percent difference (RPD). Prior to analyses, two different types of outlier tests were performed to remove datathat were not representative of the overall laboratory performance observed during the studies, in accordance with ASTM protocol.Microbiological method performance generally is difficult to assess. Method recoveries can be problematic due to uneven distribution of organisms in suspension and densitiesof organisms can change between enumeration and spiking. The QC criteria developed for the fecal coliform and Salmonella methods will allow laboratories to assess laboratory and method performance, identify and solve problems, and assess quality of occurrence results.