A comparison of culture methods and polymerase chain reaction in detecting Clostridioides difficile from hospital surfaces.

Introduction. Environmental surveillance for Clostridioides difficile is challenging. There are no internationally agreed recommendations on which method should be used when environmental surveillance is undertaken.Aim. To compare the detection of C. difficile by RT-PCR to culture-based methods and to determine which is more sensitive and specific in the clinical environment.Methods. Forty-four near-patient areas of C. difficile-positive patients were sampled using contact plates and moistened flocked swabs.Results. Detection using moistened flocked swabs followed by RT-PCR or culture detected more C. difficile than contact plates. The sensitivity and specificity of a RT-PCR assay for tcdB compared to the culture methods was 76 and 91 %, respectively.Conclusion. Despite the lower sensitivity and specificity, RT-PCR could potentially offer a more rapid and practical alternative.

Can e-learning improve the performance of undergraduate medical students in Clinical Microbiology examinations?

BACKGROUND: Clinical Microbiology is a core subject in medical undergraduate curricula. However, students struggle to cover the content and clinically contextualise basic microbiology. Our aim was to evaluate student engagement with new e-learning material and to investigate the impact it had on examination performance in a Clinical Microbiology module. METHODS: An online resource was designed to support didactic teaching in a Fundamentals of Clinical Microbiology module. One cohort of students had access to the online material (2017/2018 class) and the other did not (2016/2017 class). Each cohort sat the same multiple-choice question (MCQ) and short-note question (SNQ) examination papers and the impact of engagement with the online resource and examination performance was analysed. RESULTS: Both groups were of the same academic standard prior to beginning the module. In the 2017/2018 cohort, 227/309 (73.5%) students had ≥80% engagement with the content. Students engaged most with the index of pathogens and pathogen focused clinical cases related to diverse genera and families of clinically important microorganisms. A statistically higher difference in the mean percentage grade in both the MCQ and SNQ examinations was seen for 2017/2018 compared to 2016/2017 cohort. For the MCQ examination, the 2017/2018 cohort were on average 5.57% (95% confidence interval (CI): 3.92 to 7.24%; P < 0.001) higher, and for the SNQ examination the 2017/2018 cohort were on average 2.08% (95% CI: 0.74 to 3.41%; P = 0.02) higher. When the results were adjusted for previous examination performance, for every percentage increase in online engagement the grade in the SNQ examination only increased by 0.05% (95% CI: 0.02 to 0.08) on average. CONCLUSIONS: These findings suggest students engage with e-learning when studying and that such activities may help students perform better in assessments.

Is online case-based learning effective in helping undergraduate medical students choose the appropriate antibiotics to treat important infections?

BACKGROUND: Medical students are frequently confused about indication for and choice of antibiotic. We developed an online learning resource that focused on antibiotic stewardship and important infections where medical students could practise their antibiotic decision-making skills safely. METHODS: The resource was made available to third-year undergraduate medical students via their virtual learning environment. It covered the theory and fundamentals of antibiotic stewardship and five clinical cases covering important infections. We assessed the number of attempts taken to achieve the required level of understanding to pass each activity and surveyed a selection of students for their feedback. RESULTS: Of 310 students, over 80% engaged with the theory-based components, with an average score exceeding 90% (range 93.4%-99.7%). Eighty-three percent (258/310) engaged with the first two cases (Clostridioides difficile infection and pyelonephritis) but only 61% (189/310) of students completed the fifth case on bacterial meningitis. Only 49.4% (153/310) of students completed all five cases, with 48% (73/153) of these achieving ≥90% on their first attempt of the associated quizzes. Fifty-nine percent (23/39) agreed or strongly agreed that the quality of the learning resource was excellent. Seventy-two percent (28/39) agreed or strongly agreed that the objectives of the resource were relevant to their needs as undergraduate medical students. Only 33% (13/39) reported the resource would change their practice. CONCLUSIONS: Student feedback was positive but engagement with the cases needs improvement. Highlighting the utility of case-based technology-enhanced learning as a safe place to practise antibiotic decision-making skills among students may improve this.

Decontamination of Hospital Surfaces With Multijet Cold Plasma: A Method to Enhance Infection Prevention and Control?

OBJECTIVE To evaluate the efficacy of a multijet cold-plasma system and its efficacy in decontaminating 2 surfaces commonly found in hospitals DESIGN An in vitro study of common causes of healthcare-acquired infection METHODS Log10 9 cultures of methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended spectrum ß-lactamase-producing Escherichia coli, and Acinetobacter baumannii were applied to 5-cm2 sections of stainless steel and mattress. Human serum albumin (HSA) was used as a proxy marker for organic material, and atomic force microscopy (AFM) was used to study the impact on bacterial cell structure. The inoculated surfaces were exposed to a cold-air-plasma-generating multijet prototype for 15, 20, 30, and 45 seconds. RESULTS After 45 seconds, at least 3 to 4 log reductions were achieved for all bacteria on the mattress, while 3 to 6 log reductions were observed on stainless steel. The presence of HSA had no appreciable effect on bacterial eradication. The surfaces with bacteria exposed to AFM showed significant morphological changes indicative of "etching" due to the action of highly charged ions produced by the plasma. CONCLUSION This multijet cold-plasma prototype has the potential to augment current environmental decontamination approaches but needs further evaluation in a clinical setting to confirm its effectiveness. Infect Control Hosp Epidemiol 2017;38:1182-1187.

A comparative study: do "clickers" increase student engagement in multidisciplinary clinical microbiology teaching?

BACKGROUND: Audience response devices, or "clickers", have been used in the education of future healthcare professionals for several years with varying success. They have been reported to improve the learning experience by promoting engagement and knowledge retention. In 2014, our department evaluated the use of "clickers" in a newly introduced multidisciplinary approach to teaching large groups of third year medical students clinical cases developed around a microbiology theme. METHODS: Six multidisciplinary teaching sessions covering community-acquired pneumonia, tuberculosis, infective endocarditis, peritonitis, bloodstream infection with pyelonephritis and bacterial meningitis were included in the study. Three involved the use of the "clickers" and three did not. Consenting undergraduate students attended the designated classes and afterwards answered a short online quiz relating to the session. Students also answered a short questionnaire about the "clickers" to gauge their attitudes on the use of these devices. RESULTS: Of 310 students, 294 (94.8%) agreed to participate in the study. Interestingly, the grades of online quizzes after a session where a "clicker" was used were slightly lower. Looking only at the grades of students who engaged completely with the process (n = 19), there was no statistical difference to suggest that the devices had a positive or negative impact on knowledge retention. However, student attitudes to using the devices were positive overall. Fifty-five percent strongly agreed and 27% agreed that teaching sessions where the "clickers" were used were more engaging. Thirty-four percent strongly agreed and 36% agreed that the "clickers" made important concepts more memorable and 54% felt the device enhanced their understanding of the topic being covered. CONCLUSIONS: Overall, it appears that "clickers" help in improving student engagement in large classroom environments, enhance the learning experience, and are received positively by medical students but their impact on knowledge retention is variable.

Cold air plasma to decontaminate inanimate surfaces of the hospital environment.

The hospital environment harbors bacteria that may cause health care-associated infections. Microorganisms, such as multiresistant bacteria, can spread around the patient's inanimate environment. Some recently introduced biodecontamination approaches in hospitals have significant limitations due to the toxic nature of the gases and the length of time required for aeration. This study evaluated the in vitro use of cold air plasma as an efficient alternative to traditional methods of biodecontamination of hospital surfaces. Cultures of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli, and Acinetobacter baumannii were applied to different materials similar to those found in the hospital environment. Artificially contaminated sections of marmoleum, mattress, polypropylene, powder-coated mild steel, and stainless steel were then exposed to a cold air pressure plasma single jet for 30 s, 60 s, and 90 s, operating at approximately 25 W and 12 liters/min flow rate. Direct plasma exposure successfully reduced the bacterial load by log 3 for MRSA, log 2.7 for VRE, log 2 for ESBL-producing E. coli, and log 1.7 for A. baumannii. The present report confirms the efficient antibacterial activity of a cold air plasma single-jet plume on nosocomial bacterially contaminated surfaces over a short period of time and highlights its potential for routine biodecontamination in the clinical environment.

Ventriculoperitoneal shunt-related infections caused by Staphylococcus epidermidis: pathogenesis and implications for treatment.

The insertion of medical devices, such as intraventricular shunts, is often complicated by infection leading to ventriculitis. Frequently, such infections result from colonisation and subsequent biofilm formation on the surfaces of the shunts by Staphylococcus epidermidis. The pathogenesis of neurosurgical shunt-related infection is complex with interactions between the pathogen, the device and the unique local immunological environment of the central nervous system (CNS). An ability to form biofilm, the main virulence determinant of Staphylococcus epidermidis, facilitates protection of the organism from the host defences while still initiating an immunological response. The presence of the blood brain barrier (BBB) and the biofilm itself also complicates treatment, which presents many challenges when managing shunt infections. A greater understanding of the interplay between S. epidermidis and the CNS could potentially improve the diagnosis, treatment and management of such infections. This review describes the pathogenesis, treatment and implications of S. epidermidis ventriculoperitoneal shunt-related infections, concentrating on recent research and the implications for treatment.

Candida infection of the central nervous system following neurosurgery: a 12-year review.

BACKGROUND: Candida infection of the central nervous system (CNS) following neurosurgery is relatively unusual but is associated with significant morbidity and mortality. We present our experience with this infection in adults and discuss clinical characteristics, treatment options, and outcome. METHODS: All episodes of Candida isolated from the central nervous system were identified by searching our laboratory database. Review of the cases was performed by means of a retrospective chart review. RESULTS: Eleven episodes of Candida CSF infection following neurosurgery were identified over a 12-year period. Candida albicans was the predominant species isolated (n = 8, 73%). All infections were associated with foreign intracranial material, nine with external ventricular drains (82%), one with a ventriculoperitoneal shunt, one with a lumbar drain, and one with Gliadel wafers (1,3-bis [2-chloroethyl]-1-nitrosurea). Fluconazole or liposomal amphotericin B were the most common anti-fungal agents used. The mortality rate identified in our series was 27%. CONCLUSIONS: Candida infection following neurosurgery remains a relatively rare occurrence but one that causes significant mortality. These are complex infections, the management of which benefits from a close liaison between the clinical microbiologist and neurosurgeon. Prompt initiation of antifungal agents and removal of infected devices offers the best hope of a cure.

Biofilm characteristics of Staphylococcus epidermidis isolates associated with device-related meningitis.

Staphylococcus epidermidis biofilm causes device-related meningitis in neurosurgical patients. This study assessed the contribution of polysaccharide and protein to the development of a strong biofilm-positive phenotype in four S. epidermidis isolates associated with probable device-related meningitis, under varying environmental conditions. RT-PCR analysis of the intercellular adhesion operon (icaADBC) and assessment of polysaccharide intercellular adhesin (PIA) production indicated a correlation between increased icaA transcription and PIA production in ica(+) isolates grown in medium with 4 % ethanol and 4 % NaCl. Treatment of biofilm with sodium metaperiodate caused dispersion of adhered cells (P <0.0001), indicating involvement of PIA. Transcriptional levels of protein factors revealed that atlE transcription levels were similar in all isolates, whilst aap levels were variable, with induction being seen in two isolates following growth in the presence of alcohol or salt. Transcription of agr did not influence protein expression and RNAIII transcription varied among the strains. Although aap transcription was induced, the treatment of biofilm with proteinase K did not always disperse the biofilm. Our data suggest that, among the three ica(+) S. epidermidis isolates clinically associated with meningitis that were studied, PIA contributed to the strong biofilm-positive phenotype, whereas protein factors appeared to have a secondary role.

Staphylococcus epidermidis polysaccharide intercellular adhesin induces IL-8 expression in human astrocytes via a mechanism involving TLR2.

Staphylococcus epidermidis is an opportunistic biofilm-forming pathogen associated with neurosurgical device-related meningitis. Expression of the polysaccharide intercellular adhesin (PIA) on its surface promotes S. epidermidis biofilm formation. Here we investigated the pro-inflammatory properties of PIA against primary and transformed human astrocytes. PIA induced IL-8 expression in a dose- and/or time-dependent manner from U373 MG cells and primary normal human astrocytes. This effect was inhibited by depletion of N-acetyl-beta-d-glucosamine polymer from the PIA preparation with Lycopersicon esculentum lectin or sodium meta-periodate. Expression of dominant-negative versions of the TLR2 and TLR4 adaptor proteins MyD88 and Mal in U373 MG cells inhibited PIA-induced IL-8 production. Blocking IL-1 had no effect. PIA failed to induce IL-8 production from HEK293 cells stably expressing TLR4. However, in U373 MG cells which express TLR2, neutralization of TLR2 impaired PIA-induced IL-8 production. In addition to IL-8, PIA also induced expression of other cytokines from U373 MG cells including IL-6 and MCP-1. These data implicate PIA as an important immunogenic component of the S. epidermidis biofilm that can regulate pro-inflammatory cytokine production from human astrocytes, in part, via TLR2.