Investigation of genetic associations of mother to neonate group B streptococcus

Group B Streptococcus (GBS, Streptococcus agalactiae) is a leading cause of neonatal infections and stillbirths in infants under 3 months old. Vertical transmission remains the most common route of transmission to infants ≤6 days old due to ingestion of GBS laden fluids during delivery, or in utero. The route of transmission to infants 7-90 days old is less well understood. To understand the genetic distribution of GBS strains from The Gambia, and the associations of mother to infant transmission, we used whole genome sequencing. Genomic analysis of 781 GBS isolates from 154 GBS colonised women and their infants ≤90 days old from The Gambia revealed the most common serotypes were serotypes V (42%), II (27%), III (13%), IV (9%), Ia (7%) and Ib (2%). Multilocus sequence typing (MLST) grouped the isolates into 20 STs, with four novel STs identified which were ST1354, ST1355, ST1356 and ST1357. All GBS isolates clustered into CC1 (43.9%), CC26 (25.9%), CC17 (10%), CC19 (7.2%), CC23 (7.2%) and CC10 (5.1%). Antibiotic resistance was low in GBS in The Gambia. No isolates were resistant to penicillin or clindamycin, but resistance to macrolides (5%), tetracycline (99%), and fluoroquinolones (2.3%) were observed. Using comparative genomics to identify genetic mutations that are associated with mother to infant GBS transmission, multiple mutations were identified in 94 mother-infant pairs colonised with the same ST. Mutations were found in key virulence factors such as bibA and bca, but no gene had a mutation in more than one mother-infant pair, except for mutations in ispE, bioB, rsmB, infB and nylA_1, where each of these genes were found in two mother-infant pairs. Overall, this work shows GBS strains in colonisation are heterogeneous and GBS can undergo genetic changes within a short duration of ≤89 days.Open Acces

Albumin-bilirubin grade predicts the outcomes of liver resection versus radiofrequency ablation for very early/early stage of hepatocellular carcinoma

Background and purposeWhether liver resection or ablation should be the first-line treatment for very early/early hepatocellular carcinoma (HCC) in patients who are candidates for both remains controversial. The aim of this study was to determine if the newly-developed Albumin-Bilirubin (ALBI) grade might help in treatment selections and to evaluate the survival of patients treated with liver resection and radiofrequency ablation (RFA).MethodsPatients with BCLC stage 0/A HCC who were treated with curative liver resection and RFA from 2003 to 2013 were included. Baseline clinical and laboratory parameters were retrieved and reviewed from the hospital database. Liver function and its impact on survival was assessed by the ALBI score. Overall and disease-free survivals were compared between the two groups.Results488 patients underwent liver resection (n = 318) and RFA (n = 170) for BCLC stage 0/A HCC during the study period. Liver resection offered superior survival to RFA in patients with BCLC stage 0/A HCC in the whole cohort. After propensity score matching, liver resection offered superior overall survival and disease-free survival to RFA in patients with ALBI grade 1 (P = 0.0002 and P ConclusionsLiver resection offered superior survival to RFA in patients with BCLC stage 0/A HCC. The ALBI grade could identify those patients with worse liver function who did not gain any survival advantage from curative liver resection

Systematic review of Group B Streptococcal capsular types, sequence types and surface proteins as potential vaccine candidates.

BACKGROUND: 21 million pregnant women worldwide (18%) are estimated to carry Group B Streptococcus (GBS), which is a risk for invasive disease in newborns, pregnant women, and stillbirths. Adults ≥ 60 years or with underlying health conditions are also vulnerable to invasive GBS disease. We undertook systematic reviews on GBS organism characteristics including: capsular polysaccharide (serotype), sequence type (multi-locus sequence types (MLST)), and virulence proteins. We synthesised data by at-risk populations, to inform vaccine development. METHODS: We conducted systematic reviews and meta-analyses to estimate proportions of GBS serotypes for at risk populations: maternal colonisation, invasive disease in pregnant women, stillbirths, infants 0-90 days age, and older adults (≥60 years). We considered regional variation and time trends (2001-2018). For these at-risk population groups, we summarised reported MLST and surface proteins. RESULTS: Based on 198 studies (29247isolates), 93-99% of GBS isolates were serotypes Ia, Ib, II, III, IV and V. Regional variation is likely, but data gaps are apparent, even for maternal colonisation which has most data. Serotype III dominates for infant invasive disease (60%) and GBS-associated stillbirths (41%). ST17 accounted for a high proportion of infant invasive disease (41%; 95%CI: 35-47) and was found almost exclusively in serotype III strains, less present in maternal colonisation (9%; 95%CI:6-13),(4%; 95%CI:0-11) infant colonisation, and adult invasive disease (4%, 95%CI:2-6). Percentages of strains with at least one of alp 1, alp2/3, alpha C or Rib surface protein targets were 87% of maternal colonisation, 97% infant colonisation, 93% infant disease and 99% adult invasive disease. At least one of three pilus islands proteins were reported in all strains. DISCUSSION: A hexavalent vaccine (serotypes Ia, Ib, II, III, IV and V) might provide comprehensive cover for all at-risk populations. Surveillance of circulating, disease-causing target proteins is useful to inform vaccines not targeting capsular polysaccharide. Addressing data gaps especially by world region and some at-risk populations (notably stillbirths) is fundamental to evidence-based decision-making during vaccine design

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Probable Airborne Transmission of Burkholderia pseudomallei Causing an Urban Outbreak of Melioidosis during Typhoon Season in Hong Kong, China. <subtitle>Urban Outbreak of Melioidosis in Hong Kong</subtitle>

ABSTRACTBetween January 2015 and October 2022, 38 patients with culture-confirmed melioidosis were identified in the Kowloon West (KW) Region, Hong Kong. Notably, thirty of them were clustered in the Sham Shui Po (SSP) district, which covers an estimated area of 2.5 km2. Between August and October 2022, 18 patients were identified in this district after heavy rainfall and typhoons. The sudden upsurge in cases prompted an environmental investigation, which involved collecting 20 air samples and 72 soil samples from residential areas near the patients. A viable isolate of Burkholderia pseudomallei was obtained from an air sample collected at a building site five days after a typhoon. B. pseudomallei DNA was also detected in 21 soil samples collected from the building site and adjacent gardening areas using full-length 16S rRNA gene sequencing, suggesting that B. psuedomallei is widely distributed in the soil environment surrounding the district. Core genome-multilocus sequence typing showed that the air sample isolate was phylogenetically clustered with the outbreak isolates in KW Region. Multispectral satellite imagery revealed a continuous reduction in vegetation region in SSP district by 162,255 m2 from 2016 to 2022, supporting the hypothesis of inhalation of aerosols from the contaminated soil as the transmission route of melioidosis during extreme weather events. This is because the bacteria in unvegetated soil are more easily spread by winds. In consistent with inhalational melioidosis, 24 (63.2%) patients had pneumonia. Clinicians should be aware of melioidosis during typhoon season and initiate appropriate investigation and treatment for patients with compatible symptoms