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Background A prophylactic Staphylococcus aureus four-antigen vaccine (SA4Ag) is under development for prevention of invasive S. aureus disease. A preliminary S. aureus three-antigen vaccine (SA3Ag) was reformulated to include a novel manganese transporter protein (MntC or rP305A). This study describes the first-in-human dose-finding, safety, and immunogenicity results for SA4Ag. Methods In this double-blind, sponsor-unblind, placebo-controlled, phase 1/2 study, 454 healthy adults aged 18–64 years were randomised to receive a single dose of one of three formulations of SA4Ag with escalating dose levels of rP305A or placebo. Functional immune responses were measured using opsonophagocytic activity (OPA) killing and fibrinogen-binding inhibition (FBI) assays; antigen-specific immunogenicity was assessed using a four-plex competitive Luminex® immunoassay (cLIA). Results A high proportion of SA4Ag recipients met the pre-defined antibody thresholds for each antigen at Day 29. A substantial and dose-level dependent immune response was observed for rP305A, with up to 18-fold rises in cLIA titres at Day 29. Robust functional responses were demonstrated, with >80-fold and >20-fold rises in OPA assay titres at Day 29 using S. aureus strains expressing capsular polysaccharide serotypes 5 and 8, respectively. Durable antibody responses were observed through month 12, gradually waning from peak levels achieved by days 11–15. SA4Ag was well tolerated, and no vaccine-related serious adverse events were reported. Conclusions Single-dose vaccination of SA4Ag in healthy adults aged 18–64 years safely induced rapid and robust functional immune responses that were durable through month 12, supporting further development of this vaccine. Trial registration number: NCT01364571

Introduction Native Americans in the southwestern United States have a higher risk for many infectious diseases and may be at higher risk for Staphylococcus aureus due to the high prevalence of risk factors for S. aureus. Recent data on invasive S. aureus infections among Native Americans are limited. Methods Active population- and laboratory-based surveillance was conducted in 2016–2017 on the Navajo Nation to document the rate of invasive S. aureus. A case of invasive S.aureus infection was defined as a Native American individual with S. aureus isolated from a normally sterile body site whose reported community of residence was on or around the Navajo Nation. Results One hundred and fifty-nine cases of invasive S. aureus from 152 individuals were identified. The median age of cases was 56.3 years and 35% were female. Thirty-five percent of cases had community-acquired infections. Ninety-three percent of cases had underlying medical conditions, including diabetes (60%) and obesity (42%), 28% of cases had a documented prior S. aureus infection, and 33% were infected with methicillin-resistant S. aureus. The annual incidence of invasive S. aureus and of invasive methicillin-resistant S. aureus was 64.9/100,000 persons and 21.2/100,000 persons, respectively. Conclusions This community has a high burden of invasive S. aureus infections. Further research is needed to identify prevention strategies and opportunities for intervention.

Invasive pneumococcal disease (IPD) is vaccine-preventable but few data on the incidence of PD exist for Indian children.To assess the feasibility of implementing prospective, population-based surveillance for PD among children less than five years of age. Settings and Design :Hospitals and health agencies, Bangalore, India. Retrospective review and analysis of hospitalization records as well as public health and demographic data.Records for 2006 hospitalizations for pneumococcal disease-associated syndromes (meningitis, pneumonia and sepsis) were identified at three pediatric referral hospitals (Indira Gandhi Institute of Child Health, Kempegowda Institute of Child Health and Vani Vilas Hospital) in Bangalore using International Classification of Diseases, 9th revision codes. Hospital microbiology laboratory records were assessed to ensure capacity for identifying S. pneumoniae. Population data were identified from national census and polio surveillance data.The Bangalore city southern zone includes 33 wards occupying 51 Km 2 with 150,945 children between 0-5 years of age served by three referral pediatric hospitals. From January--December 2006, records of these three hospitals showed 2,219 hospitalizations of children less than five years of age (967 pneumonia, 768 sepsis, and 484 meningitis) with PD-associated diagnoses (southern zone area incidence: 0.15/100,000 PD-associated hospitalizations, less than five years of age). There were 178 deaths in children less than five years of age, of which 87 were attributable to sepsis, 56 to pneumonia and 35 to meningitis.Our analysis suggests that the PD-associated disease burden in Bangalore is high and local institutions have capacity for population-based surveillance. In a prospective study, systematic attention to potential barriers in identifying children with pneumococcal infections will improve estimation of IPD incidence in India.

Coagulase-negative staphylococci (CoNS) are important pathogens in premature neonates; decreasing glycopeptide susceptibility has been observed among these isolates. The epidemiology of colonization with CoNS, the organisms' vancomycin susceptibilities, and genetic relatedness were studied over 6 months in a tertiary-care neonatal unit. A total of 321 isolates of CoNS were isolated. Seventy-five percent of the infants were colonized at admission, and virtually all were colonized thereafter. Common species were Staphylococcus epidermidis (69%), S. warneri (12%), S. haemolyticus (9.7%), and S. hominis (5.6%). A total of 3.9% of CoNS isolates had decreased vancomycin susceptibility (DVS) (MICs > 2.0 μg/ml); isolate recovery was associated with a stay in a neonatal intensive care unit for >28 days ( P = 0.039), vancomycin exposure ( P = 0.021), and S. warneri colonization ( P < 0.0001). Nine of 12 (75%) CoNS with DVS were S. warneri , had enhanceable high-level resistance in vitro, were indistinguishable or closely related by pulsed-field gel electrophoresis, and were different from 29 vancomycin-susceptible S. warneri isolates. Epidemiological analysis suggested unsuspected nosocomial spread. Species determination in certain settings may aid in the understanding of emerging nosocomial problems.