Approaches for Mitigating Microbial Biofilm-Related Drug Resistance: A Focus on Micro- and Nanotechnologies.

Biofilms play an essential role in chronic and healthcare-associated infections and are more resistant to antimicrobials compared to their planktonic counterparts due to their (1) physiological state, (2) cell density, (3) quorum sensing abilities, (4) presence of extracellular matrix, (5) upregulation of drug efflux pumps, (6) point mutation and overexpression of resistance genes, and (7) presence of persister cells. The genes involved and their implications in antimicrobial resistance are well defined for bacterial biofilms but are understudied in fungal biofilms. Potential therapeutics for biofilm mitigation that have been reported include (1) antimicrobial photodynamic therapy, (2) antimicrobial lock therapy, (3) antimicrobial peptides, (4) electrical methods, and (5) antimicrobial coatings. These approaches exhibit promising characteristics for addressing the impending crisis of antimicrobial resistance (AMR). Recently, advances in the micro- and nanotechnology field have propelled the development of novel biomaterials and approaches to combat biofilms either independently, in combination or as antimicrobial delivery systems. In this review, we will summarize the general principles of clinically important microbial biofilm formation with a focus on fungal biofilms. We will delve into the details of some novel micro- and nanotechnology approaches that have been developed to combat biofilms and the possibility of utilizing them in a clinical setting.

Patterns of cervicofacial infections: analysis of the use of computed tomography.

OBJECTIVE: The aim of this study was to determine which clinical, microbiological and radiological factors contribute to the need for repeated computed tomography (CT) imaging and surgical drainage. METHODS: In this retrospective study, medical records of all patients who underwent surgical drainage of cervicofacial infections between January 2006 and August 2010 at a London tertiary referral centre were analysed. Patients who underwent CT due to a clinical suspicion of deep cervicofacial infection were divided into two groups: (1) single CT only and (2) repeated CT imaging. These groups were then compared using Fisher's exact test. Patients requiring return to theatre for additional exploration and drainage of collection were also analysed. RESULTS: Four hundred and forty-five patients were admitted with cervicofacial infections, of whom 78 patients had a CT scan. The most frequent site of infection was the submandibular space, involving 54 % of patients. Among the patients who underwent repeated imaging compared to those who underwent a single CT scan, the parapharyngeal space was involved significantly more frequently (5/24 vs 2/54, p = 0.03), as was the presence of multiple-space infections (13/24 vs 15/54, p = 0.04) and osteomyelitis (4/24 vs 0/54, p = 0.007). Multiple-space infection was also more frequent in the group who required repeat visits to theatre as compared to those who had a single drainage (7/9 vs 23/69, p = 0.02). CONCLUSIONS: The majority of cervicofacial infections are managed without the need for CT scanning. Presence of infection in multiple cervicofacial spaces and in the parapharyngeal space and presence of osteomyelitis result in persistent sepsis necessitating repeat imaging and drainage.