Enhancing employability through hospital placements for Biomedical Science students: A Case Study from the University of Essex, UK

Collaboration between Universities and hospitals has provided the National Health Service (NHS) with many excellent Biomedical Scientists through the placement year scheme. Here, we document the number of students joining the placement scheme and the number and type of hospital departments offering student placements over a 10-year period. Prior to 2012, students were able to join fully-funded placements through the Higher Education Funding Council for England (HEFCE). Since then, there has been a fluctuation in numbers completing a placement year at the University of Essex, but the employability of these graduates remains consistently higher than our 3-year graduates. We demonstrate the positive impact of completing a placement year in an NHS hospital laboratory for students, and the contribution to university metrics in good degrees and graduate outcomes as well as the provision of much needed, qualified biomedical science staff to hospitals

Role of Acanthamoeba in urinary tract infections

Urinary Tract Infection (UTI) is the second most common healthcare associated infections (HCAI) in England. The HCAI prevalence survey data (2011) released by the Health Protection Agency (HPA) shows that UTI’s are the second most common HCAI accounting for 17.2% of the total HCAI’s in England. Escherichia coli, Klebsiella and Proteus are Gram negative bacteria frequently associated with UTI's. More HCAI's are related to the use of urinary catheters than any other medical device. An estimated 450,000 people in the UK use catheters on a long-term basis. Uropathogens are known to form biofilms on catheters causing recurrent infections. Biofilms are difficult to eradicate due to decreased antibiotic susceptibility and increased resistance. A recent study has found the presence of Acanthamoeba in urine of critically ill patients. The ubiquitous protozoan Acanthamoeba, is an opportunistic pathogen well recognised to serve as a reservoir for prokaryotes. Our recent findings (unpublished) confirm that the above mentioned bacteria can invade, survive and multiply within Acanthamoeba evading host defence and antibiotic action by forming cysts. It is our intention to investigate the presence of Acanthamoeba in urine samples collected from patients

Identification and properties of proteases from an Acanthamoeba isolate capable of producing granulomatous encephalitis

BACKGROUND: Granulomatous amoebic encephalitis due to Acanthamoeba is often a fatal human disease. However, the pathogenesis and pathophysiology of Acanthamoeba encephalitis remain unclear. In this study, the role of extracellular Acanthamoeba proteases in central nervous system pathogenesis and pathophysiology was examined. RESULTS: Using an encephalitis isolate belonging to T1 genotype, we observed two major proteases with approximate molecular weights of 150 KD and 130 KD on SDS-PAGE gels using gelatin as substrate. The 130 KD protease was inhibited with phenylmethylsulfonyl fluoride (PMSF) suggesting that it is a serine protease, while the 150 KD protease was inhibited with 1, 10-phenanthroline suggesting that it is a metalloprotease. Both proteases exhibited maximal activity at neutral pH and over a range of temperatures, indicating their physiological relevance. These proteases degrade extracellular matrix (ECM), which provide structural and functional support to the brain tissue, as shown by the degradation of collagen I and III (major components of collagenous ECM), elastin (elastic fibrils of ECM), plasminogen (involved in proteolytic degradation of ECM), as well as casein and haemoglobin. The proteases were purified partially using ion-exchange chromatography and their effects were tested in an in vitro model of the blood-brain barrier using human brain microvascular endothelial cells (HBMEC). Neither the serine nor the metalloprotease exhibited HBMEC cytotoxicity. However, the serine protease exhibited HBMEC monolayer disruptions (trypsin-like) suggesting a role in blood-brain barrier perturbations. CONCLUSION: Overall, these data suggest that Acanthamoeba proteases digest ECM, which may play crucial role(s) in invasion of the brain tissue by amoebae

Post-mortem culture of Balamuthia mandrillaris from the brain and cerebrospinal fluid of a case of granulomatous amoebic meningoencephalitis, using human brain microvascular endothelial cells

The first isolation in the UK of Balamuthia mandrillaris amoebae from a fatal case of granulomatous amoebic meningoencephalitis is reported. Using primary cultures of human brain microvascular endothelial cells (HBMECs), amoebae were isolated from the brain and cerebrospinal fluid (CSF). The cultures showed a cytopathic effect at 20–28 days, but morphologically identifiable B. mandrillaris amoebae were seen in cleared plaques in subcultures at 45 days. The identification of the organism was later confirmed using PCR on Chelex-treated extracts. Serum taken while the patient was still alive reacted strongly with slide antigen prepared from cultures of the post-mortem isolate, and also with those from a baboon B. mandrillaris strain at 1 : 10 000 in indirect immunofluorescence, but with Acanthamoeba castellanii (Neff) at 1 : 160, supporting B. mandrillaris to be the causative agent. If the presence of amoebae in the post-mortem CSF reflects the condition in life, PCR studies on CSF and on biopsies of cutaneous lesions may also be a valuable tool. The role of HBMECs in understanding the interactions of B. mandrillaris with the blood–brain barrier is discussed

Post-mortem culture of Balamuthia mandrillaris from the brain and cerebrospinal fluid of a case of granulomatous amoebic meningoencephalitis, using human brain microvascular endothelial cells.

The first isolation in the UK of Balamuthia mandrillaris amoebae from a fatal case of granulomatous amoebic meningoencephalitis is reported. Using primary cultures of human brain microvascular endothelial cells (HBMECs), amoebae were isolated from the brain and cerebrospinal fluid (CSF). The cultures showed a cytopathic effect at 20-28 days, but morphologically identifiable B. mandrillaris amoebae were seen in cleared plaques in subcultures at 45 days. The identification of the organism was later confirmed using PCR on Chelex-treated extracts. Serum taken while the patient was still alive reacted strongly with slide antigen prepared from cultures of the post-mortem isolate, and also with those from a baboon B. mandrillaris strain at 1:10,000 in indirect immunofluorescence, but with Acanthamoeba castellanii (Neff) at 1:160, supporting B. mandrillaris to be the causative agent. If the presence of amoebae in the post-mortem CSF reflects the condition in life, PCR studies on CSF and on biopsies of cutaneous lesions may also be a valuable tool. The role of HBMECs in understanding the interactions of B. mandrillaris with the blood-brain barrier is discussed

Acanthamoeba induces cell-cycle arrest in host cells

Acanthamoeba can cause fatal granulomatous amoebic encephalitis (GAE) and eye keratitis. However, the pathogenesis and pathophysiology of these emerging diseases remain unclear. In this study, the effects of Acanthamoeba on the host cell cycle using human brain microvascular endothelial cells (HBMEC) and human corneal epithelial cells (HCEC) were determined. Two isolates of Acanthamoeba belonging to the T1 genotype (GAE isolate) and T4 genotype (keratitis isolate) were used, which showed severe cytotoxicity on HBMEC and HCEC, respectively. No tissue specificity was observed in their ability to exhibit binding to the host cells. To determine the effects of Acanthamoeba on the host cell cycle, a cell-cycle-specific gene array was used. This screened for 96 genes specific for host cell-cycle regulation. It was observed that Acanthamoeba inhibited expression of genes encoding cyclins F and G1 and cyclin-dependent kinase 6, which are proteins important for cell-cycle progression. Moreover, upregulation was observed of the expression of genes such as GADD45A and p130 Rb, associated with cell-cycle arrest, indicating cell-cycle inhibition. Next, the effect of Acanthamoeba on retinoblastoma protein (pRb) phosphorylation was determined. pRb is a potent inhibitor of G1-to-S cell-cycle progression; however, its function is inhibited upon phosphorylation, allowing progression into S phase. Western blotting revealed that Acanthamoeba abolished pRb phosphorylation leading to cell-cycle arrest at the G1-to-S transition. Taken together, these studies demonstrated for the first time that Acanthamoeba inhibits the host cell cycle at the transcriptional level, as well as by modulating pRb phosphorylation using host cell-signalling mechanisms. A complete understanding of Acanthamoeba–host cell interactions may help in developing novel strategies to treat Acanthamoeba infections

The role of Acanthamoeba in recurrent urinary tract infections

Urinary Tract Infections (UTI) are clinically important in the current health scenario due to emerging antibiotic resistance and increasing recurrence levels. In the UK nearly half of all women have had at least one episode of UTI in their life time while one in every 2000 men develop the infection each year (Urinary Tract Infections – Adults, 2012). In infants and children, UTI is the most common bacterial infection (NICE, 2007). A variety of pathogens are known to cause UTI. According to Davis and Flood (2011) E. coli is the causative agent of UTI in about 80% of community acquired and 50% of hospital acquired UTI. In a UK wide multicentre study conducted by Farrell et al (2003), E. coli was found to be the predominant pathogen isolated from patients suffering from UTI followed by Enterococcus faecalis, Klebsiella pneumonia and Proteus mirabilis. Over the years a variety of bacteria have developed different tactics to survive encystment, resist phagocytosis and multiply within Acanthamoeba, which is a free-living amoeba. The intracellular settings of Acanthamoeba protect the bacterial endosymbionts from adverse conditions such as the human immune response (Lovieno et al, 2010). Santos et all (2009) conducted a study based on the hypothesis that urinary pathogenic bacteria can potentially use Acanthamoeba as a protective tool to survive antimicrobial effect, disinfection and the host immune response. They evaluated 63 urine samples collected from indwelling catheters of critically ill patients. In an interesting finding, 23% of these samples tested positive for the presence of Acanthamoeba spp. Although this study had few limitations, it definitely paved the way for more research into the role of Acanthamoeba in HCAI, particularly human UTI

A novel antimicrobial urinary catheter

Urinary tract infections (UTI) are one of the most common healthcare associated infections (HCAI) accounting for 17.2% of the total HCAI’s in England, out of which 43% of infections were associated with the use of an indwelling catheter. Catheter associated UTI (CAUTI) caused by uropathogenic biofilm formation is responsible for prolonged hospital admissions, increased costs and significant morbidity. The NHS routinely uses silver alloy-coated latex catheters and silicone catheters impregnated with nitrofurazone to prevent CAUTIs. However, numerous studies have questioned their antimicrobial efficacy. This raises the urgent need to develop novel catheters that can inhibit bacterial colonization. The present study provides the in vitro evidence to support the use of novel Cetylpyridinium chloride (CPC) impregnated catheters in preventing biofilm formation. CPC impregnated catheters were prepared using a 3-step medical implant impregnation process. A biofilm microtitre plate assay was used to evaluate the antimicrobial effect of CPC, and the efficacy of impregnated catheters was assessed using an in vitro biofilm catheter colonization model. Non-impregnated catheters were used as control. Growth of Proteus mirabilis and extended spectrum beta lactamase (ESBL) positive and negative strains of Escherichia coli and Klebsiella was completely inhibited by CPC (30 μg/ml) after 24h of incubation in artificial urine medium. The novel CPC impregnated catheters were highly efficacious in inhibiting biofilm colonization of all uropathogens tested at all time intervals. Taken together, our preliminary results provide promising evidence for the potential application of CPC impregnated catheters in preventing CAUTI

The role of Acanthamoeba in recurrent urinary tract infections

Urinary Tract Infections (UTI) are clinically important in the current health scenario due to emerging antibiotic resistance and increasing recurrence levels. In the UK nearly half of all women have had at least one episode of UTI in their life time while one in every 2000 men develop the infection each year (Urinary Tract Infections – Adults, 2012). In infants and children, UTI is the most common bacterial infection (NICE, 2007). A variety of pathogens are known to cause UTI. According to Davis and Flood (2011) E. coli is the causative agent of UTI in about 80% of community acquired and 50% of hospital acquired UTI. In a UK wide multicentre study conducted by Farrell et al (2003), E. coli was found to be the predominant pathogen isolated from patients suffering from UTI followed by Enterococcus faecalis, Klebsiella pneumonia and Proteus mirabilis. Over the years a variety of bacteria have developed different tactics to survive encystment, resist phagocytosis and multiply within Acanthamoeba, which is a free-living amoeba. The intracellular settings of Acanthamoeba protect the bacterial endosymbionts from adverse conditions such as the human immune response (Lovieno et al, 2010). Santos et all (2009) conducted a study based on the hypothesis that urinary pathogenic bacteria can potentially use Acanthamoeba as a protective tool to survive antimicrobial effect, disinfection and the host immune response. They evaluated 63 urine samples collected from indwelling catheters of critically ill patients. In an interesting finding, 23% of these samples tested positive for the presence of Acanthamoeba spp. Although this study had few limitations, it definitely paved the way for more research into the role of Acanthamoeba in HCAI, particularly human UTI.</p

A novel antimicrobial urinary catheter

Urinary tract infections (UTI) are one of the most common healthcare associated infections (HCAI) accounting for 17.2% of the total HCAI’s in England, out of which 43% of infections were associated with the use of an indwelling catheter. Catheter associated UTI (CAUTI) caused by uropathogenic biofilm formation is responsible for prolonged hospital admissions, increased costs and significant morbidity. The NHS routinely uses silver alloy-coated latex catheters and silicone catheters impregnated with nitrofurazone to prevent CAUTIs. However, numerous studies have questioned their antimicrobial efficacy. This raises the urgent need to develop novel catheters that can inhibit bacterial colonization. The present study provides the in vitro evidence to support the use of novel Cetylpyridinium chloride (CPC) impregnated catheters in preventing biofilm formation. CPC impregnated catheters were prepared using a 3-step medical implant impregnation process. A biofilm microtitre plate assay was used to evaluate the antimicrobial effect of CPC, and the efficacy of impregnated catheters was assessed using an in vitro biofilm catheter colonization model. Non-impregnated catheters were used as control. Growth of Proteus mirabilis and extended spectrum beta lactamase (ESBL) positive and negative strains of Escherichia coli and Klebsiella was completely inhibited by CPC (30 ?g/ml) after 24h of incubation in artificial urine medium. The novel CPC impregnated catheters were highly efficacious in inhibiting biofilm colonization of all uropathogens tested at all time intervals. Taken together, our preliminary results provide promising evidence for the potential application of CPC impregnated catheters in preventing CAUTIs</p