Rapid expansion and international spread of M1UK in the post-pandemic UK upsurge of Streptococcus pyogenes.

The UK observed a marked increase in scarlet fever and invasive group A streptococcal infection in 2022 with severe outcomes in children and similar trends worldwide. Here we report lineage M1UK to be the dominant source of invasive infections in this upsurge. Compared with ancestral M1global strains, invasive M1UK strains exhibit reduced genomic diversity and fewer mutations in two-component regulator genes covRS. The emergence of M1UK is dated to 2008. Following a bottleneck coinciding with the COVID-19 pandemic, three emergent M1UK clades underwent rapid nationwide expansion, despite lack of detection in previous years. All M1UK isolates thus-far sequenced globally have a phylogenetic origin in the UK, with dispersal of the new clades in Europe. While waning immunity may promote streptococcal epidemics, the genetic features of M1UK point to a fitness advantage in pathogenicity, and a striking ability to persist through population bottlenecks.

Metabolic bone disease in patients with epilepsy and the use of antiepileptic drugs - Insight from a Danish cross-sectional study.

BACKGROUND: Osteoporosis is a bone disorder defined by a decrease in bone mineral density (BMD) which can lead to an increased risk of fractures. Patients with epilepsy are more prone to having fractures. When accounting for seizure-related fractures, the epilepsy patient population still suffers from an increased risk of fractures. This can be attributed to adverse effects of antiepileptic drugs (AEDs). AIM: The aim of this study was to investigate the association between the use of AEDs and decreased BMD in a large unselected population of Danish patients with epilepsy. METHOD: The study was a cross-sectional study based on data retrieved from 835 patients visiting an outpatient Epilepsy Clinic in Glostrup, Denmark, from January 1st 2006 - January 31st 2018. The data included results from DXA-scans and demographic information. Logistic regression models and other statistical analyses were performed. RESULTS: The results showed that the odds for having osteoporosis when taking EIAEDs were 2.2 (95 % CI: 1.2-3.8, P = 0.007) times higher than those taking NEIAEDs. Furthermore, the odds for having osteoporosis increased with duration of epilepsy (OR = 1.0, 95 % CI: 1.0 - 1.0, P = 0.001) and when the patients consume two AEDs compared to one AED (OR = 2.3, 95 % CI: 1.3-4.1, P < 0.001). Additionally, consuming three AEDs compared to one lead to a 2.3 times higher risk of having osteoporosis (95 % CI: 1.2-4.4, P = 0.01). CONCLUSION: When accounted for many riskfactors, EIAEDs, polytherapy with AEDs and duration of epilepsy are correlated with osteoporosis. There is a need for using these known riskfactors as guidelines in indentifying patients at increased risk of developing osteoporosis.

Genomic sequencing of a national emm66 group A streptococci (GAS) outbreak among people who inject drugs and the homeless community in England and Wales, January 2016-May 2017.

An outbreak of an uncommon emm type (emm66.0) of group A streptococcus (GAS) occurred in England and Wales between January 2016 and May 2017, involving 52 individuals who were homeless or injecting drugs users. In order to investigate the outbreak, epidemiological and network analysis were performed; moreover 55 isolates (32 outbreak, 5 non-outbreak and 13 historical - 2005-2015) were tested with whole genome sequencing (WGS), antimicrobial resistance determination, Bayesian evolutionary analysis (BEAST). Forty one isolates (including 32 outbreak strains) belonged to a single emm66.0 clade (average SNP difference 6.6; range 0-16 SNPs) separate from the other isolates and two strains previously considered part of the outbreak (SNP average: 5876; range 93-8417 SNPs). Antibiotic resistance was not detected in the outbreak clone. No common source of infection was identified. WGS confirmed expansion of an emm66.0 clone in a hard-to-reach population and enabled refinement of the initial case definition.

Evaluation of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for the Identification of Group B Streptococcus.

OBJECTIVE: Group B Streptococcus (GBS) is a leading cause of neonatal meningitis and sepsis worldwide. Intrapartum antibiotics given to women carrying GBS are an effective means of reducing disease in the first week of life. Rapid and reliable tests are needed to accurately identify GBS from these women for timely intrapartum antibiotic administration to prevent neonatal disease. Many laboratories now use matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) by direct plating or cell lysis for the identification of GBS isolates. The cell lysis step increases time to results for clinical samples and is more complex to perform. Therefore, we seek to evaluate the sensitivity and specificity of the quicker and more rapid direct plating method in identifying GBS. RESULTS: We directly compared swab isolates analysed by both direct plating and cell lysis method and demonstrated that direct plating has a sensitivity and specificity of 0.97 and 1, respectively, compared to an additional cell lysis step. We demonstrated that MALDI-TOF MS can be successfully used for batch processing by the direct plating method which saves time. These results are reassuring for laboratories worldwide who seek to identify GBS from swabs samples as quickly as possible.

Genome analysis following a national increase in Scarlet Fever in England 2014.

BACKGROUND: During a substantial elevation in scarlet fever (SF) notifications in 2014 a national genomic study was undertaken of Streptococcus pyogenes (Group A Streptococci, GAS) isolates from patients with SF with comparison to isolates from patients with invasive disease (iGAS) to test the hypotheses that the increase in SF was due to either the introduction of one or more new/emerging strains in the population in England or the transmission of a known genetic element through the population of GAS by horizontal gene transfer (HGT) resulting in infections with an increased likelihood of causing SF. Isolates were collected to provide geographical representation, for approximately 5% SF isolates from each region from 1st April 2014 to 18th June 2014. Contemporaneous iGAS isolates for which genomic data were available were included for comparison. Data were analysed in order to determine emm gene sequence type, phylogenetic lineage and genomic clade representation, the presence of known prophage elements and the presence of genes known to confer pathogenicity and resistance to antibiotics. RESULTS: 555 isolates were analysed, 303 from patients with SF and 252 from patients with iGAS. Isolates from patients with SF were of multiple distinct emm sequence types and phylogenetic lineages. Prior to data normalisation, emm3 was the predominant type (accounting for 42.9% of SF isolates, 130/303 95%CI 37.5-48.5; 14.7% higher than the percentage of emm3 isolates found in the iGAS isolates). Post-normalisation emm types, 4 and 12, were found to be over-represented in patients with SF versus iGAS (p < 0.001). A single gene, ssa, was over-represented in isolates from patients with SF. No single phage was found to be over represented in SF vs iGAS. However, a "meta-ssa" phage defined by the presence of :315.2, SPsP6, MGAS10750.3 or HK360ssa, was found to be over represented. The HKU360.vir phage was not detected yet the HKU360.ssa phage was present in 43/63 emm12 isolates but not found to be over-represented in isolates from patients with SF. CONCLUSIONS: There is no evidence that the increased number of SF cases was a strain-specific or known mobile element specific phenomenon, as the increase in SF cases was associated with multiple lineages of GAS.

Integration of Genomic and Other Epidemiologic Data to Investigate and Control a Cross-Institutional Outbreak of Streptococcus pyogenes.

Single-strain outbreaks of Streptococcus pyogenes infections are common and often go undetected. In 2013, two clusters of invasive group A Streptococcus (iGAS) infection were identified in independent but closely located care homes in Oxfordshire, United Kingdom. Investigation included visits to each home, chart review, staff survey, microbiologic sampling, and genome sequencing. S. pyogenes emm type 1.0, the most common circulating type nationally, was identified from all cases yielding GAS isolates. A tailored whole-genome reference population comprising epidemiologically relevant contemporaneous isolates and published isolates was assembled. Data were analyzed independently using whole-genome multilocus sequencing and single-nucleotide polymorphism analyses. Six isolates from staff and residents of the homes formed a single cluster that was separated from the reference population by both analytical approaches. No further cases occurred after mass chemoprophylaxis and enhanced infection control. Our findings demonstrate the ability of 2 independent analytical approaches to enable robust conclusions from nonstandardized whole-genome analysis to support public health practice.

The expression of lipopolysaccharide by strains of Shigella dysenteriae, Shigella flexneri and Shigella boydii and their cross-reacting strains of Escherichia coli.

Strains of Shigella dysenteriae, Shigella flexneri and Shigella boydii express lipopolysaccharides, that enable the serotyping of strains based on their antigenic structures. Certain strains of S. dysenteriae, S. flexneri and S. boydii are known to share epitopes with strains of Escherichia coli; however, the lipopolysaccharide profiles of the cross-reacting organisms have not been compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) lipopolysaccharides profiling. In the present study, type strains of these bacteria were examined using SDS-PAGE/silver staining to compare their respective lipopolysaccharide profiles. Strains of S. dysenteriae, S. boydii and S. flexneri all expressed long-chain lipopolysaccharide, with distinct profile patterns. The majority of strains of Shigella spp., known to cross-react with strains of E. coli, had lipopolysaccharide profiles quite distinct from the respective strain of E. coli. It was concluded that while cross-reacting strains of Shigella spp. and E. coli may express shared lipopolysaccharide epitopes, their lipopolysaccharide structures are not identical.

Cystic pancreatic neoplasms: observe or operate.

OBJECTIVE: The objectives of this analysis were to define the incidence, natural history, and predictors of neoplasia in pancreatic cysts to determine which patients can safely be observed and which should undergo an operation. SUMMARY BACKGROUND DATA: With advancements in imaging technology, cystic lesions of the pancreas are being detected with increased frequency. Many of these lesions are small and asymptomatic, but they may be associated with pancreatitis or have malignant potential. Therefore, the management of these patients is complex, and knowledge of pancreatic cyst natural history and predictors of neoplasia are important. METHODS: From January 1995 through December 2002, all radiologic, surgical, and pathology records were reviewed for the presence of pancreatic cysts. In determining natural history, only patients with 2 scans more than 1 month apart at our institution were included. Patients with a clinical history and laboratory evidence of pancreatitis and/or pathologic confirmation of a pseudocyst were excluded. Factors analyzed as potential predictors of neoplasia included age, gender, cyst size, and symptoms. Serous cystadenomas, solid and cystic papillary (Hamoudi) tumors, lymphoepithelial cysts and simple cysts were all benign, whereas mucinous cystic neoplasms, intraductal papillary mucinous neoplasm, cystic neuroendocrine tumors, and cystadenocarcinomas were considered to be premalignant or malignant. RESULTS: Among 24,039 CT or MR scans, 290 patients (1.2%) had pancreatic cysts, and 168 of these patients (0.7%) had no documentation of pancreatitis. Seventy-nine of these patients with 103 cysts had more than 1 scan with an average interval of 16 months. These cysts increased in size in 19%, did not change in 59% and decreased in 22% of patients. Forty-nine patients underwent surgery for 14 benign (serous cystadenomas = 10, Hamoudi = 2, lymphoepithelial = 1, simple = 1) 25 premalignant (mucinous cystic neoplasm =16, intraductal papillary mucinous neoplasm = 5, neuroendocrine tumors = 4), or 10 malignant (intraductal papillary mucinous neoplasm = 7, cystadenocarcinomas = 3) lesions. Gender and cyst size did not predict neoplasia. However, presence of symptoms predicted premalignant or malignant pathology (60% vs. 23%, P < 0.05), and age over 70 years was associated with malignancy (60% vs. 21%, P < 0.02). CONCLUSIONS: These data suggest that cystic pancreatic neoplasms 1) occur in 0.7% of patients, 2) increase in 19% over 16 months, and 3) are likely (60%) to be malignant in patients older than 70 years. Therefore, we recommend surgical excision for pancreatic cysts that are increasing under observation, symptomatic, or detected radiologically in fit older patients.

Activation of a subpopulation of orexin/hypocretin-containing hypothalamic neurons by GABAA receptor-mediated inhibition of the nucleus accumbens shell, but not by exposure to a novel environment.

Gamma-amino butyric acid (GABA)A receptor stimulation in the nucleus accumbens shell produces intense hyperphagia in rats and increases Fos expression in the lateral hypothalamus. To explore the involvement of hypothalamic orexin/hypocretin- or melanin concentrating hormone-immunoreactive neurons in this effect, the GABAA agonist, muscimol (0, 50 ng), was infused directly into the nucleus accumbens shell of rats; 90 min later, their brains were collected and subsequently processed for immunohistochemistry. A group exposed to a novel environment was included to evaluate the specificity of Fos expression changes with regard to general arousal. Alternating sections through the hypothalamus were double-stained for orexin/hypocretin-Fos or melanin concentrating hormone-Fos combinations. Intra-accumbens shell muscimol treatment significantly increased the percentage of orexin/hypocretin-containing neurons expressing Fos in the lateral, but not medial, portion of the perifornical/lateral hypothalamic area. Regardless of treatment condition, greater percentages of orexin/hypocretin-containing neurons in the medial portion of the hypothalamus expressed Fos relative to cells located more laterally. None of the manipulations increased Fos expression in melanin concentrating hormone-immunoreactive neurons. Muscimol treatment also markedly increased Fos expression in the arcuate nucleus, which connects reciprocally to the lateral/perifornical hypothalamic area. Thus, orexin/hypocretin-containing neurons in lateral sectors of the hypothalamus, along with cells in the arcuate nucleus, display phasic increases in Fos expression after an orexigenic pharmacological manipulation of the nucleus accumbens shell, but to a lesser degree after the heightened arousal associated with exposure to a novel environment.

Overlapping distributions of orexin/hypocretin- and dopamine-beta-hydroxylase immunoreactive fibers in rat brain regions mediating arousal, motivation, and stress.

A double-label immunohistochemical study was carried out to investigate overlap between dopamine-beta-hydroxylase (DbetaH) -immunopositive projections and the projections of hypothalamic neurons containing the arousal- and feeding-related peptide, orexin/hypocretin (HCRT), in rat brain. Numerous intermingled HCRT-immunopositive and DbetaH-immunopositive fibers were seen in a ventrally situated corridor extending from the hypothalamus to deep layers of the infralimbic cortex. Both fiber types avoided the nucleus accumbens core, caudate putamen, and the globus pallidus. In the diencephalon, overlap was observed in several hypothalamic areas, including the perifornical, dorsomedial, and paraventricular nuclei, as well as in the paraventricular thalamic nucleus. Intermingled HCRT-containing and DbetaH-containing fibers extended from the hypothalamus into areas within the medial and central amygdala, terminating at the medial border of the lateral subdivision of the central nucleus of the amygdala. Dense overlap between the two fiber types was also observed in the periaqueductal gray, particularly in the vicinity of the dorsal raphe, as well as (to a lesser extent) in the ventral tegmental area, the retrorubral field, and the pedunculopontine tegmental nucleus. Hypocretin-containing cell bodies, located in the perifornical and lateral hypothalamus, were embedded within a dense plexus of DbetaH-immunopositive fibers and boutons, with numerous cases of apparent contacts of DbetaH-containing boutons onto HCRT-immunopositive soma and dendrites. HCRT-containing fibers were observed amid the noradrenergic cells of the locus coeruleus, and in the vicinity of the A1, A2, and A5 cell groups. Hence, the projections of these two arousal-related systems, originating in distinctly different parts of the brain, jointly target several forebrain regions and brainstem monoaminergic nuclei involved in regulating core motivational processes.