Introduction. Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) and varicella-zoster virus (VZV) are established causes of central nervous system infection, whereas human herpesvirus 6 (HHV-6) DNA may be detected in more heterogeneous contexts. However, longitudinal patterns of recurrent cerebrospinal fluid (CSF) PCR positivity remain poorly characterized. Hypothesis/Gap statement. When the same herpesvirus is detected in CSF on different dates, the meaning of the interval between positive results is uncertain. Its observed distribution may also depend on retesting opportunities and changes in testing practice. Aim. To describe inter-positive intervals across five herpesvirus targets and assess how their interpretation changes with operational cut-offs and calendar-period testing patterns. Methodology. We retrospectively analysed qualitative CSF PCR results for five herpesviruses from 16 March 2010 to 30 March 2026. Recurrent positivity required at least two distinct positive dates per patient–virus pair. First-to-last intervals were classified at 30 days, with exploratory cut-offs of 14, 60 and 90 days. Calendar-period analyses used FilmArray Meningitis/Encephalitis panel introduction on 10 November 2020 as the boundary and period-specific positive pairs as denominators. Results. Among 19,959 interpretable target-level results (994 positive), 33 recurrent pairs were identified: HHV-6 (18), VZV (7), HSV-1 (5), HSV-2 (2) and cytomegalovirus (1). The median first-to-last inter-positive interval was 11 days (interquartile range, 4–185; range, 1–864). Nineteen intervals were <30 days and 14 were ≥30 days; HHV-6 accounted for 10 longer pairs, all pre-implementation, limiting target-specific interpretation. The HHV-6 versus non-HHV-6 comparison was not significant (10/18 versus 4/15; two-sided Fisher’s exact P =0.158). Within-period recurrent positivity was 24/771 (3.1%) in the pre-implementation calendar period and 8/176 (4.5%) in the post-implementation period; corresponding HHV-6 recurrent positivity was 17/302 (5.6%) and 1/84 (1.2%). Conclusion. Recurrent CSF herpesvirus PCR positivity showed heterogeneous target composition and inter-positive intervals. These data cannot distinguish clustered retesting, persistence, reactivation or chromosomal integration. Interpretation requires prior testing history and linked clinical or quantitative virological data.
Introduction. Enteropathogenic Escherichia coli (EPEC) is a diarrhoeagenic pathotype of E. coli, historically associated with gastrointestinal (GI) disease in infants and young children. Hypothesis/Gap statement. Although EPEC was the subject of extensive microbiological and epidemiological investigations throughout the twentieth century, in recent years, surveillance of diarrhoeagenic E. coli (DEC) has focused on Shiga toxin-producing E. coli. Consequently, the true clinical and community burden of EPEC is unknown. Aim. The aim of the study was to review the microbiological typing data and demographic data linked to EPEC isolates and cases diagnosed from 2011 to 2024 in England and to assess the risk to public health. Methodology. Faecal samples that tested positive by PCR for DEC at local microbiology diagnostic laboratories were referred to the UK Health Security Agency (UKHSA) for confirmation and culture. Isolates identified as EPEC were sequenced on the Illumina HiSeq and NextSeq platforms. Sequence type, serotype and antimicrobial resistance (AMR) profile were derived from the genome sequence. Age, sex and travel histories were linked to the typing data. Results. A total of 3,091 EPEC isolates from cases resident in England were notified to the UKHSA between January 2011 and October 2024, with 96% classified as atypical EPEC (aEPEC). The number of referred isolates increased more than eightfold, from 78 in 2011 to 654 in 2024, likely due to the widespread implementation of PCR for the detection of GI pathogens at the local hospital level. There was a slightly higher proportion of females (51.7%), and the highest proportion of cases occurred in the 0-4 age group (30.1%). Reported symptoms included diarrhoea (86.57%) and/or bloody diarrhoea (24.25%) and abdominal pain (9.05%), and 33cases were diagnosed clinically with haemolytic uraemic syndrome. The population structure was diverse with 447 different serotypes identified, and 24.5% of isolates were resistant to three or more antibiotic classes. Conclusion. A high proportion of cases were infants or young children. Strains causing travellers' diarrhoea exhibited multidrug resistance and extensive drug resistance. Further research on potential animal reservoirs, likely food vehicles, exposure risks and pathogenic potential of EPEC, is warranted. To facilitate future investigations, we recommend that EPEC should be part of the diagnostic algorithm in the UK and that surveillance strategies should include analysis of travel data and monitoring AMR to inform the global perspective.
Introduction. Third-generation cephalosporin-resistant Klebsiella pneumoniae (3GC-R-KP) is a significant global health concern. The widespread production of beta-lactamases and virulence factors contributes to multidrug resistance and complicates treatment. Hypothesis/Gap Statement. The potential co-evolution of resistance and virulence in 3GC-R-KP remains unclear, raising the risk of emerging 'highly resistant-hypervirulent' clones. Aim. To analyse the resistance spectrum, virulence characteristics and biofilm formation ability of 3GC-R-KP and to clarify its enzyme production types and carriage of virulence factors. Methodology. The antimicrobial susceptibility of each strain, the hypermucoviscous (HM) phenotype (determined by the string test) and the biofilm-forming capacity (assessed using the crystal violet staining method) were examined. Three beta-lactamase phenotypes were detected using the double disc synergy test, the disc approximation test and the modified carbapenem inactivation method, respectively. Simultaneously, multiplex PCR technology was employed to screen for drug resistance genes and virulence genes, and statistical analysis was performed on the detection results. Results. Most isolates were multidrug-resistant strains with biofilm-forming ability, and the main resistance phenotypes were extended-spectrum beta-lactamase (ESBL) and carbapenemase production. Genotypically, bla(SHV) (95.8%; note: this represents only the carriage rate of the gene, and the wild-type does not possess ESBL activity) and bla(KPC) (76%) were the most common. The virulence genes entB (99%) and mrkD (96.9%) were detected at extremely high rates, indicating that drug resistant strains generally possess high virulence potential, and there is a coexistence of resistance and virulence genes. Conclusion. 3GC-R-KP exhibits a high rate of multidrug resistance and widespread carriage of hypervirulence genes. Traditional hypervirulent K. pneumoniae (hvKP) is evolving into 'dual-risk' strains that possess both hypervirulence and multidrug resistance by acquiring resistance genes, thereby posing an increased clinical threat. The HM phenotype alone insufficient to define hvKP, and accurate typing requires the detection of virulence genes. The co-occurrence of resistance genes and virulence factors suggests possible coevolution between them.
Introduction. Molecular assays such as the Hologic Aptima ® Vaginitis Panel and Seegene Allplex ™ Vaginitis assay offer improved sensitivity and multiplex detection for the diagnosis of vaginitis compared with the non-molecular standard of care. Gap Statement. Evidence comparing the relative performance of Aptima versus Seegene is limited, as is knowledge of Aptima’s compatibility with non-proprietary swabs. Aim. This prospective study assessed the diagnostic performance of the Aptima BV (bacterial vaginosis) and Aptima CV/TV assays ( Candida vaginitis/ Trichomonas vaginitis) alongside the Seegene Allplex assay in symptomatic women (≥18 years) presenting for vaginitis testing in primary care in France. Methodology. Two vaginal swabs were taken per patient: one Aptima Multitest Swab and one non-proprietary Σ-TRANSWAB liquid Amies collection swab. Aptima swab data were used solely to confirm performance of the Aptima assays under current test conditions, while all primary assay comparisons were performed using Σ-TRANSWAB samples. These comparisons were performed for each assay relative to Nugent score (for BV) or culture (for CV), as well as Aptima relative to Seegene. Results. In total, 500 women underwent vaginitis testing between July and August 2024. When using non-proprietary Σ-TRANSWAB collection methods, sensitivity and specificity values for the Aptima BV assay were 96.7 and 89.7% relative to Nugent score, and 89.9 and 90.6% for Seegene Allplex relative to Nugent score. Among ‘intermediate BV’ samples ( n =66), agreement between Seegene Allplex and Nugent score was 1.5%. Sensitivity and specificity values for the detection of CV were 88.6 and 90.8% for the Aptima CV/TV assay, and 90.2 and 93.7% for Seegene Allplex. Assay detection of TV could not be validated due to an insufficient number of TV-positive samples ( n =1). These findings were consistent with Aptima’s performance when using proprietary collection methods. Conclusion. Overall, the Aptima Vaginitis Panel demonstrated comparably high diagnostic performance to Seegene Allplex for the detection of BV and CV when using a non-proprietary sample collection method. TV prevalence was too low in this cohort to permit meaningful assay evaluation for this pathogen.
Antimicrobial resistance (AMR) is a serious and growing threat in Mexico. To support cross-sector dialogue and policy development around AMR, the Science and Technology Network, the Department for Business and Trade and the Microbiology Society convened a one-day workshop at the British Embassy in Mexico City. This commentary synthesises the key themes from the workshop discussions and presents the desired outcomes, challenges and policy interventions identified by participants.
