Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living). Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH) revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease.

Background: Antibiotic resistance in Escherichia coli, a member of the Enterobacteriaceae, is of particular concern because it is the most common (Gram-negative) pathogen causing nosocomial and community infections. Researchers are now considering the use of phages for the control of various antibiotic-resistant bacterial infections. Objectives: The purpose of this study was to isolate and characterize a novel pathogenic/lytic phage that targets multi-drug resistant (MDR) E. coli 3, and to investigate its effectiveness at lysing this bacterium. Materials and Methods: A clinical strain of E. coli 3 was identified based on its 16S rRNA sequencing and its antibiotic resistance profile was determined by the disc diffusion method. A bacteriophage was isolated from wastewater and its various characteristics, such as host range, heat tolerance, pH stability, one step growth, total protein content, and genome size, were determined. The antibacterial property of the phage was determined against log-phase bacterial planktonic cells at 37°C. Results: The bacteriophage, designated MJ1, was isolated by testing against a clinical MDR E. coli 3 strain. The MJ1 phage showed a wide range of heat and pH stability. The phage morphology, determined by transmission electron microscopy, revealed a structure comprised of a head (108 ± 0.2 nm long by 128 ± 0.5 nm wide) and a contractile tail (123 ± 0.5 nm long by 15 - 26 nm wide). These features placed the MJ1 phage in the family Myoviridae and the order Caudovirales. Eleven structural proteins (17 to 200 kDa) for this phage were detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A double stranded DNA, approximately 32 kb, in size was detected for this phage on agarose gels. The phage efficacy against E. coli 3 planktonic cells was also investigated. The MJ1 phage demonstrated a very good capability to reduce the numbers of E. coli 3 planktonic cells, as determined by a change in the bacterial growth (an optical density decrease at 600 nm from 0.40 to 0.12). Conclusions: MJ1 phage has much potential for use in phage therapy and other applications. Keywords: Bacteriophage; Nosocomial; Contractile; Planktonic; Escherichia coli; Myoviridae