Isolation and Pathogenic Characterization of Vibrio bivalvicida Associated With a Massive Larval Mortality Event in a Commercial Hatchery of Scallop Argopecten purpuratus in Chile

The VPAP30 strain was isolated as the highly predominant bacteria from an episode of massive larval mortality occurring in a commercial culture of the Chilean scallop Argopecten purpuratus. The main aims of this study were, to characterize and identify the pathogenic strain using biochemical and molecular methods, to demonstrate its pathogenic activity on scallop larvae, to characterize its pathogenic properties and to describe the chronology of the pathology. The pathogenic strain was identified as Vibrio bivalvicida based on its phenotypic properties, the multilocus sequence analysis (MLSA) of eight housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA, and topA) and different in silico genome-to-genome comparisons. When triplicate cultures of healthy 10 days old scallop larvae were challenged with 1 × 105 colony forming units (CFU) mL-1 of the VPAP30 strain, percentages of larval survival of 78.9 ± 3.3%, 34.3 ± 4.9%, and 0% were observed at 12, 2,4 and 36 h, respectively, whereas uninfected larval cultures showed survival rates of 97.4 ± 1.2% after of 48 h. Clinical symptoms exhibited by the scallop larvae infected with the VPAP30 strain include the accumulation of bacteria around the scallop larvae, velum disruption and necrosis of digestive gland. The 50% lethal dose (LD50) of VPAP30 strain at 24 and 48 h was 1.3 × 104 and 1.2 × 103 CFU mL-1, respectively. The invasive pathogenic activity of the VPAP30 strain was investigated with staining of the bacterial pathogen with 5-DTAF and analyzing bacterial invasion using epifluorescence, and a complete bacterial dissemination inside the larvae at 24 h post-infection was observed. When scallop larvae were inoculated with cell-free extracellular products (ECPs) of VPAP30, the larval survival rate was 59.5 ± 1.7%, significantly (P < 0.001) lower than the control group (97.4 ± 1.2%) whereas larvae treated with heat-treated ECPs exhibited a survival rate of 61.6 ± 1.8% after 48 h of exposure. V. bivalvicida VPAP30 exhibits high pathogenic activity on scallop larvae, mediated both by bacterial invasion and the production of toxigenic heat-stable compounds. This report constitutes the first isolation of V. bivalvicida out of Europe and extends the host range of this species, having demonstrated its pathogenic activity on the Chilean scallop larvae (A. purpuratus). These results supporting the pathogenic potential of V. bivalvicida to kill the larvae of a broad range of bivalve species reared in hatcheries located in the Atlantic and the Pacific coasts.This study was financially supported by the Science and Technology National Council (CONICYT) of Chile by the Postdoctoral Project Grant No. 3150395 and FONDECYT grant No. 1140734 and FONDEF ID16I10291S

Isolation and Pathogenic Characterization of Vibrio bivalvicida Associated With a Massive Larval Mortality Event in a Commercial Hatchery of Scallop Argopecten purpuratus in Chile

The VPAP30 strain was isolated as the highly predominant bacteria from an episode of massive larval mortality occurring in a commercial culture of the Chilean scallop Argopecten purpuratus. The main aims of this study were, to characterize and identify the pathogenic strain using biochemical and molecular methods, to demonstrate its pathogenic activity on scallop larvae, to characterize its pathogenic properties and to describe the chronology of the pathology. The pathogenic strain was identified as Vibrio bivalvicida based on its phenotypic properties, the multilocus sequence analysis (MLSA) of eight housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA, and topA) and different in silico genome-to-genome comparisons. When triplicate cultures of healthy 10 days old scallop larvae were challenged with 1 × 105 colony forming units (CFU) mL-1 of the VPAP30 strain, percentages of larval survival of 78.9 ± 3.3%, 34.3 ± 4.9%, and 0% were observed at 12, 2,4 and 36 h, respectively, whereas uninfected larval cultures showed survival rates of 97.4 ± 1.2% after of 48 h. Clinical symptoms exhibited by the scallop larvae infected with the VPAP30 strain include the accumulation of bacteria around the scallop larvae, velum disruption and necrosis of digestive gland. The 50% lethal dose (LD50) of VPAP30 strain at 24 and 48 h was 1.3 × 104 and 1.2 × 103 CFU mL-1, respectively. The invasive pathogenic activity of the VPAP30 strain was investigated with staining of the bacterial pathogen with 5-DTAF and analyzing bacterial invasion using epifluorescence, and a complete bacterial dissemination inside the larvae at 24 h post-infection was observed. When scallop larvae were inoculated with cell-free extracellular products (ECPs) of VPAP30, the larval survival rate was 59.5 ± 1.7%, significantly (P &lt; 0.001) lower than the control group (97.4 ± 1.2%) whereas larvae treated with heat-treated ECPs exhibited a survival rate of 61.6 ± 1.8% after 48 h of exposure. V. bivalvicida VPAP30 exhibits high pathogenic activity on scallop larvae, mediated both by bacterial invasion and the production of toxigenic heat-stable compounds. This report constitutes the first isolation of V. bivalvicida out of Europe and extends the host range of this species, having demonstrated its pathogenic activity on the Chilean scallop larvae (A. purpuratus). These results supporting the pathogenic potential of V. bivalvicida to kill the larvae of a broad range of bivalve species reared in hatcheries located in the Atlantic and the Pacific coasts

Targeting a Newly Established Spontaneous Feline Fibrosarcoma Cell Line by Gene Transfer

Fibrosarcoma is a deadly disease in cats and is significantly more often located at classical vaccine injections sites. More rare forms of spontaneous non-vaccination site (NSV) fibrosarcomas have been described and have been found associated to genetic alterations. Purpose of this study was to compare the efficacy of adenoviral gene transfer in NVS fibrosarcoma. We isolated and characterized a NVS fibrosarcoma cell line (Cocca-6A) from a spontaneous fibrosarcoma that occurred in a domestic calico cat. The feline cells were karyotyped and their chromosome number was counted using a Giemsa staining. Adenoviral gene transfer was verified by western blot analysis. Flow cytometry assay and Annexin-V were used to study cell-cycle changes and cell death of transduced cells. Cocca-6A fibrosarcoma cells were morphologically and cytogenetically characterized. Giemsa block staining of metaphase spreads of the Cocca-6A cells showed deletion of one of the E1 chromosomes, where feline p53 maps. Semi-quantitative PCR demonstrated reduction of p53 genomic DNA in the Cocca-6A cells. Adenoviral gene transfer determined a remarkable effect on the viability and growth of the Cocca-6A cells following single transduction with adenoviruses carrying Mda-7/IL-24 or IFN-γ or various combination of RB/p105, Ras-DN, IFN-γ, and Mda-7 gene transfer. Therapy for feline fibrosarcomas is often insufficient for long lasting tumor eradication. More gene transfer studies should be conducted in order to understand if these viral vectors could be applicable regardless the origin (spontaneous vs. vaccine induced) of feline fibrosarcomas

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Cytological diagnostic features of late breast implant seromas. From reactive to anaplastic large cell lymphoma

Late breast implant seroma may be the presentation of a breast implant-associated anaplastic large cell lymphoma (BI-ALCL), which claims for a prompt recognition. However, BI-ALCL diagnosis on fine-needle aspiration (FNA) might be challenging for pathologists lacking experience with peri-implant breast effusions. Sixty-seven late breast implant seromas collected by FNA from 50 patients were evaluated by Papanicolaou smear stain and immunocytochemistry on cell blocks. A diagnostic algorithm based on the cellular composition, cell morphology and percentage of CD30+ cells was developed. Histological evaluation of the corresponding peri-prosthetic capsules was also performed. Most of the effusions (91% of the samples) were classified as reactive and 9% as BI-ALCL. In the BI-ALCL cases, medium-to-large atypical cells expressing CD30 represented more than 70% of the cellularity, whereas in in the reactive effusions CD30+ elements were extremely rare (<5%) and consisted of non-atypical elements. The reactive effusions were categorized into three patterns: i) acute infiltrate with prominent neutrophilic component (33% of the samples); ii) mixed infiltrate characterized by a variable number of neutrophils, lymphocytes and macrophages (30% of the samples); iii) chronic infiltrate composed predominantly of T lymphocytes or macrophages with only sporadic granulocytes (37% of the samples). The inflammatory cytological patterns were consistent with the histology of the corresponding capsules. Our results indicate that cytological analysis of late breast implant effusions, supported by the knowledge of the heterogeneous cytomorphological spectrum of late seromas, is a valuable approach for the early recognition of BI-ALCL