Publications by authors named "Penelope Cliff"

Article Synopsis
  • Clinical metagenomics enhances the detection of microorganisms in clinical samples through genomic sequencing while minimizing human DNA interference, using a rapid mechanical method for simultaneous RNA and DNA analysis.
  • The method involves mechanically lysing human cells and employing nonspecific endonuclease to deplete human DNA, allowing the conversion of RNA to dsDNA for comprehensive sequencing.
  • Results indicate high sensitivity and specificity in identifying various pathogens, with a promising concordance with traditional testing methods, suggesting potential for routine use in microbiology labs with further validation.
View Article and Find Full Text PDF

Respiratory metagenomics (RMg) needs evaluation in a pilot service setting to determine utility and inform implementation into routine clinical practice. Feasibility, performance, and clinical impacts on antimicrobial prescribing and infection control were recorded during a pilot RMg service. RMg was performed on 128 samples from 87 patients with suspected lower respiratory tract infection (LRTI) on two general and one specialist respiratory ICUs at Guy's and St Thomas' NHS Foundation Trust, London.

View Article and Find Full Text PDF

Background: Monkeypox virus (MPXV) is the causative agent of the 2022 monkeypox global outbreak. Rapid detection of MPXV infection is essential to inform patient management and public health response. Currently, there is a lack of established real-time PCR assays to support a rapid diagnosis of monkeypox.

View Article and Find Full Text PDF
Article Synopsis
  • Clinical metagenomics (CMg) could enhance antimicrobial treatment and infection control, especially highlighted by the SARS-CoV-2 pandemic, which increased risks of infections from drug-resistant pathogens in ICUs.
  • A study involving 43 respiratory samples from intubated COVID-19 patients showed that an 8-hour CMg workflow was 92% sensitive and 82% specific in identifying bacteria, while also detecting antibiotic-resistant genes that could change treatment plans.
  • CMg testing allows for timely pathogen detection and resistance predictions, suggesting it could transform infection management in ICUs and warrants further clinical evaluation for broader implementation.
View Article and Find Full Text PDF

The emergence of variants of SARS-CoV-2 has created challenges for the testing infrastructure. Although large-scale genome sequencing of SARS-CoV-2 has facilitated hospital and public health responses, access to sequencing facilities globally is variable and turnaround times can be significant, so there is a requirement for rapid and cost-effective alternatives. Applying a polymerase chain reaction (PCR)-based single nucleotide polymorphism (SNP) approach enables rapid (<4 h) identification of SARS-CoV-2 lineages from nucleic acid extracts, through the presence or absence of a panel of defined of genomic polymorphisms.

View Article and Find Full Text PDF

There is a worldwide need for reagents to perform SARS-CoV-2 detection. Some laboratories have implemented kit-free protocols, but many others do not have the capacity to develop these and/or perform manual processing. We provide multiple workflows for SARS-CoV-2 nucleic acid detection in clinical samples by comparing several commercially available RNA extraction methods: QIAamp Viral RNA Mini Kit (QIAgen), RNAdvance Blood/Viral (Beckman) and Mag-Bind Viral DNA/RNA 96 Kit (Omega Bio-tek).

View Article and Find Full Text PDF

Objectives: To analyse nosocomial transmission in the early stages of the coronavirus 2019 (COVID-19) pandemic at a large multisite healthcare institution. Nosocomial incidence is linked with infection control interventions.

Methods: Viral genome sequence and epidemiological data were analysed for 574 consecutive patients, including 86 nosocomial cases, with a positive PCR test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the first 19 days of the pandemic.

View Article and Find Full Text PDF
Article Synopsis
  • Lymphogranuloma venereum (LGV), caused by certain strains of Chlamydia trachomatis, is increasing among men who have sex with men, particularly the L2b genotype.
  • Researchers used a detailed genotyping method, multi-locus tandem repeat analysis with ompA sequencing (MLVA-ompA), to investigate LGV strains in clinical samples from London genitourinary medicine clinics.
  • The study identified six distinct LGV genotypes, with the L2 type being the most common, and noted the presence of a hybrid genotype (L2b/D) similar to a strain found in Portugal, suggesting the need for ongoing monitoring in the UK.
View Article and Find Full Text PDF

Background: Lateral flow devices (LFDs) for rapid antigen testing are set to become a cornerstone of SARS-CoV-2 mass community testing, although their reduced sensitivity compared with PCR has raised questions of how well they identify infectious cases. Understanding their capabilities and limitations is, therefore, essential for successful implementation. We evaluated six commercial LFDs and assessed their correlation with infectious virus culture and PCR cycle threshold (Ct) values.

View Article and Find Full Text PDF

Objectives: Assess the feasibility and impact of nanopore-based 16S rRNA gene sequencing (Np16S) service on antibiotic treatment for acute severe pneumonia on the intensive care unit (ICU).

Methods: Speciation and sequencing accuracy of Np16S on isolates with bioinformatics pipeline optimisation, followed by technical evaluation including quality checks and clinical-reporting criteria analysing stored respiratory samples using single-sample flow cells. Pilot service comparing Np16S results with all routine respiratory tests and impact on same-day antimicrobial prescribing.

View Article and Find Full Text PDF

There is a worldwide need for reagents to perform SARS-CoV-2 detection. Some laboratories have implemented kit-free protocols, but many others do not have the capacity to develop these and/or perform manual processing. We provide multiple workflows for SARS-CoV-2 nucleic acid detection in clinical samples by comparing several commercially available RNA extraction methods: QIAamp Viral RNA Mini Kit (QIAgen), RNAdvance Blood/Viral (Beckman) and Mag-Bind Viral DNA/RNA 96 Kit (Omega Bio-tek).

View Article and Find Full Text PDF

Objectives: The increasing use of chlorhexidine for methicillin-resistant Staphylococcus aureus (MRSA) decolonization raises concerns about reduced susceptibility. We evaluated the carriage of chlorhexidine resistance genes and chlorhexidine susceptibility in MRSA before and after introduction of an institutional MRSA control programme incorporating chlorhexidine-based decolonization in 2004.

Methods: MRSA bloodstream infection (BSI) isolates identified between 2001 and 2009 were tested for spa and staphylococcal cassette chromosome mec type and carriage of qacA, qacB and smr.

View Article and Find Full Text PDF

There are strong evidences that Mycobacterium tuberculosis survives in a non-replicating state in the absence of oxygen in closed lesions and granuloma in vivo. In addition, M. tuberculosis is acid-resistant, allowing mycobacteria to survive in acidic, inflamed lesions.

View Article and Find Full Text PDF

The clinical utility of real-time PCR screening assays for methicillin (methicillin)-resistant Staphylococcus aureus (MRSA) colonization is constrained by the predictive values of their results: as MRSA prevalence falls, the assay's positive predictive value (PPV) drops, and a rising proportion of positive PCR assays will not be confirmed by culture. We provide a quantitative analysis of universal PCR screening of critical care and emergency surgical patients using the BD GeneOhm MRSA PCR system, involving 3,294 assays over six months. A total of 248 PCR assays (7.

View Article and Find Full Text PDF

Episodes of candida infection at a teaching hospital were investigated. During a 3-year period from 1998 to 2000, there were 53 cases of candidaemia. Candida albicans (64.

View Article and Find Full Text PDF