Protein Antigens Increase the Protective Efficacy of a Capsule-Based Vaccine against Staphylococcus aureus in a Rat Model of Osteomyelitis

Staphylococcus aureus is an invasive bacterial pathogen, and antibiotic resistance has impeded adequate control of infections caused by this microbe. Moreover, efforts to prevent human infections with single-component S. aureus vaccines have failed. In this study, we evaluated the protective efficacy in rats of vaccines containing both S. aureus capsular polysaccharides (CPs) and proteins. The serotypes 5 CP (CP5) and 8 CP (CP8) were conjugated to tetanus toxoid and administered to rats alone or together with domain A of clumping factor A (ClfA) or genetically detoxified alpha-toxin (dHla). The vaccines were delivered according to a preventive or a therapeutic regimen, and their protective efficacy was evaluated in a rat model of osteomyelitis. Addition of dHla (but not ClfA) to the CP5 or CP8 vaccine induced reductions in bacterial load and bone morphological changes compared with immunization with either conjugate vaccine alone. Both the prophylactic and therapeutic regimens were protective. Immunization with dHla together with a pneumococcal conjugate vaccine used as a control did not reduce staphylococcal osteomyelitis. The emergence of unencapsulated or small-colony variants during infection was negligible and similar for all of the vaccine groups. In conclusion, addition of dHla to a CP5 or CP8 conjugate vaccine enhanced its efficacy against S. aureus osteomyelitis, indicating that the inclusion of multiple antigens will likely enhance the efficacy of vaccines against both chronic and acute forms of staphylococcal disease.Fil: Lattar, Santiago Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Noto Llana, Mariangeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Denoël, Philippe. GlaxoSmithKline Vaccines; BélgicaFil: Germain, Sophie. GlaxoSmithKline Vaccines; BélgicaFil: Buzzola, Fernanda Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Lee, Jean C.. Harvard Medical School; Estados UnidosFil: Sordelli, Daniel Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Safety and Efficacy of a Single Procedure of Extraction and Reimplantation of Infected Cardiovascular Implantable Electronic Device (CIED) in Comparison with Deferral Timing: An Observational Retrospective Multicentric Study

(1) Background: Infections are among the most frequent and life-threatening complications of cardiovascular implantable electronic device (CIED) implantation. The aim of this study is to compare the outcome and safety of a single-procedure device extraction and contralateral implantation versus the standard-of-care (SoC) two-stage replacement for infected CIEDs. (2) Methods: We retrospectively included 66 patients with CIED infections who were treated at two Italian hospitals. Of the 66 patients enrolled in the study, 27 underwent a single procedure, whereas 39 received SoC treatment. All patients were followed up for 12 months after the procedure. (3) Results: Considering those lost to follow-up, there were no differences in the mortality rates between the two cohorts, with survival rates of 81.5% in the single-procedure group and 84.6% in the SoC group (p = 0.075). (4) Conclusions: Single-procedure reimplantation associated with an active antibiofilm therapy may be a feasible and effective therapeutic option in CIED-dependent and frail patients. Further studies are warranted to define the best treatment regimen and strategies to select patients suitable for the single-procedure reimplantation

99mTc-Ciprofloxacin Imaging: Still an Unsettled Issue?

The objective of this work consisted in the assessment of 99mTc-ciprofloxacin imaging performance as a diagnostic tool in an experimental rat model of osteomyelitis. Bone (tibia) infection was induced in adult rats by inoculation of a suspension containing S. aureus suspended in fibrin glue. In vivo studies by means of small animal imaging were conducted using a gamma camera. The study shows the correlation between 99mTc-ciprofloxacin positive images with bacterial bone count but also with histopathological findings in an osteomyelitis animal model, highlighting its potential as a tool in preclinical research and the accomplishment of 3Rs concept regarding welfare of laboratory animals. 99mTc-MDP scintigraphy, failed to show these correlations and therefore it may be proposed as a complementary method to diagnose and follow up the bone physiopathology in this animal model. Future perspectives of small animal imaging in order to potentiate osteomyelitis basic research will derive from numerous research works, and 99mTc-ciprofloxacin may still be a candidate for infectious diagnose and follow-up as demonstrated in this study

Range expansion and the origin of USA300 north american epidemic methicillin-resistant Staphylococcus aureus

The USA300 North American epidemic (USA300-NAE) clone of methicillin-resistant Staphylococcus aureus has caused a wave of severe skin and soft tissue infections in the United States since it emerged in the early 2000s, but its geographic origin is obscure. Here we use the population genomic signatures expected from the serial founder effects of a geographic range expansion to infer the origin of USA300-NAE and identify polymorphisms associated with its spread. Genome sequences from 357 isolates from 22 U.S. states and territories and seven other countries are compared. We observe two significant signatures of range expansion, including decreases in genetic diversity and increases in derived allele frequency with geographic distance from the Pennsylvania region. These signatures account for approximately half of the core nucleotide variation of this clone, occur genome wide, and are robust to heterogeneity in temporal sampling of isolates, human population density, and recombination detection methods. The potential for positive selection of a gyrA fluoroquinolone resistance allele and several intergenic regions, along with a 2.4 times higher recombination rate in a resistant subclade, is noted. These results are the first to show a pattern of genetic variation that is consistent with a range expansion of an epidemic bacterial clone, and they highlight a rarely considered but potentially common mechanism by which genetic drift may profoundly influence bacterial genetic variation. IMPORTANCE The process of geographic spread of an origin population by a series of smaller populations can result in distinctive patterns of genetic variation. We detect these patterns for the first time with an epidemic bacterial clone and use them to uncover the clone’s geographic origin and variants associated with its spread. We study the USA300 clone of methicillin-resistant Staphylococcus aureus, which was first noticed in the early 2000s and subsequently became the leading cause of skin and soft tissue infections in the United States. The eastern United States is the most likely origin of epidemic USA300. Relatively few variants, which include an antibiotic resistance mutation, have persisted during this clone’s spread. Our study suggests that an early chapter in the genetic history of this epidemic bacterial clone was greatly influenced by random subsampling of isolates during the clone’s geographic spread

Corrigendum: The silent epidemic of diabetic ketoacidosis at diagnosis of type 1 diabetes in children and adolescents in italy during the covid-19 pandemic in 2020(Front. Endocrinol., (2022), 13, (878634), 10.3389/fendo.2022.878634)

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Paleontology of leaf beetles

`The rate of evolution in any large group is not uniform; there are periods of relatise stability, and periods of comparatively rapid change.' Cockerell and LeVeque, 1931 To Yenli Ych, my beloved wife, a most wonderful person! The fossil record of the Chrysomelidae can be tentatively traced back to the late Paleozoic to early Mesozoic Triassic. Mesozoic records at least 9 subfamilies, 19 genera, and 35 species, are represented by the Sagrinae, the exclusively Mesozoic Proto scelinae, Clytrinae, Cryptocephalinae, Eumolpinae, Chrysomelinae. Galerucinac, Alticinae, and Cassidinae. Cenozoic records at least 12 subfamilies- 63 % of the extant- 12! genera, and 325 species, include the same extant subfamilies as well as the Donaciinae, Zeugophorinae, Criocerinae, and Hispinae and can be frequently identified to genus, especially if preserved in amber. Quaternary records are often identified to extant species. tn total, at least t3! genera about 4 % of total extant, and 357 species < 1 % have been reported. At least, 24 genera <1 % of the extant seem to be extinct. Although reliable biological information associated with the fossil chrysomelids is very scarce, it seems that most of the modern host-plant associations were established, at least, in the late Mesozoic to early Cenozoic. As a whole, stasis seems to be the general rule of the chrysomelid fossil record. Together with other faunal elements, chrysomelids, especially donaciines, have been used as biogeographic and paleoclimatological indicators in the Holocene. I

Modificaciones de la forma de la colonia de B. anthracis por acción del suero específico

Fil.: Sordelli, A. Instituto Bacteriológico. Departamento Nacional de Higiene; Argentina

Modificaciones de la forma de la colonia de B. anthracis por acción del suero específico

Fil.: Sordelli, A. Instituto Bacteriológico. Departamento Nacional de Higiene; Argentina

Las sensibilizatrices del suero anticarbuncloso

Fil.: Sordelli, A. Instituto Bacteriológico. Departamento Nacional de Higiene; Argentina