Transmission of multiresistant Salmonella Typhimurium DTI 04 between farms - investigated by the combined use of epidemiological and genotyping data

In the present investigation bacterial typing and epidemiological data was used to identity possible routes of introduction of DT104. The investigation was based on epidemiological data and isolates of 15 DT104 infected farms within a small area (15 kilometre in diameter) in Denmark, in which an almost local endemic situation has developed. In addition to the phenotypic characterisation (serotyping, phage typing, and antibiotic resistance typing) further characterisation was based on pulsed-field gel electrophoresis and plasmid profiling. The typing results combined with the epidemiological data available indicate that a DT104 infected farm might pose a risk for having DTl 04 introduced at the neighbouring farms. Furthermore, the results indicated that farms owned by the same owner are at risk of having DT104 introduced if the bacteria is found at one of the farms. Finally, sharing of manure tank or agricultural machines with a DT104 infected farm might pose a risk for DTl 04 introduction

Development of a hypoallergenic recombinant parvalbumin for first-in-man subcutaneous immunotherapy of fish allergy.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The FAST (food allergy-specific immunotherapy) project aims at developing safe and effective subcutaneous immunotherapy for fish allergy, using recombinant hypoallergenic carp parvalbumin, Cyp c 1.Preclinical characterization and good manufacturing practice (GMP) production of mutant Cyp (mCyp) c 1.Escherichia coli-produced mCyp c 1 was purified using standard chromatographic techniques. Physicochemical properties were investigated by gel electrophoresis, size exclusion chromatography, circular dichroism spectroscopy, reverse-phase high-performance liquid chromatography and mass spectrometry. Allergenicity was assessed by ImmunoCAP inhibition and basophil histamine release assay, immunogenicity by immunization of laboratory animals and stimulation of patients' peripheral blood mononuclear cells (PBMCs). Reference molecules were purified wild-type Cyp c 1 (natural and/or recombinant). GMP-compliant alum-adsorbed mCyp c 1 was tested for acute toxicity in mice and rabbits and for repeated-dose toxicity in mice. Accelerated and real-time protocols were used to evaluate stability of mCyp c 1 as drug substance and drug product.Purified mCyp c 1 behaves as a folded and stable molecule. Using sera of 26 double-blind placebo-controlled food-challenge-proven fish-allergic patients, reduction in allergenic activity ranged from 10- to 5,000-fold (1,000-fold on average), but with retained immunogenicity (immunization in mice/rabbits) and potency to stimulate human PBMCs. Toxicity studies revealed no toxic effects and real-time stability studies on the Al(OH)3-adsorbed drug product demonstrated at least 20 months of stability.The GMP drug product developed for treatment of fish allergy has the characteristics targeted for in FAST: i.e. hypoallergenicity with retained immunogenicity. These results have warranted first-in-man immunotherapy studies to evaluate the safety of this innovative vaccine.info:eu-repo/grantAgreement/EC/FP7/20187

Detection of Campylobacter Bacteria in Air Samples for Continuous Real-Time Monitoring of Campylobacter Colonization in Broiler Flocks▿

Improved monitoring tools are important for the control of Campylobacter bacteria in broiler production. In this study, we compare the sensitivities of detection of Campylobacter by PCR with feces, dust, and air samples during the lifetimes of broilers in two poultry houses and conclude that the sensitivity of detection of Campylobacter in air is comparable to that in other sample materials. Profiling of airborne particles in six poultry houses revealed that the aerodynamic conditions were dependent on the age of the chickens and very comparable among different poultry houses, with low proportions of particles in the 0.5- to 2-μm-diameter range and high proportions in the 2- to 5-μm-diameter range. Campylobacter could also be detected by PCR in air samples collected at the hanging stage during the slaughter process but not at the other stages tested at the slaughterhouse. The exploitation of airborne dust in poultry houses as a sample material for the detection of Campylobacter and other pathogens provides an intriguing possibility, in conjunction with new detection technologies, for allowing continuous or semicontinuous monitoring of colonization status

Phenol-chloroform-based RNA purification for detection of SARS-CoV-2 by RT-qPCR: Comparison with automated systems.

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly reached pandemic levels. Sufficient testing for SARS-CoV-2 has remained essential for tracking and containing the virus. SARS-CoV-2 testing capabilities are still limited in many countries. Here, we explore the use of conventional RNA purification as an alternative to automated systems for detection of SARS-CoV-2 by RT-qPCR. 87 clinical swab specimens were extracted by conventional phenol-chloroform RNA purification and compared to commercial platforms for RNA extraction and the fully integrated Cobas®6800 diagnostic system. Our results show that the conventional RNA extraction is fully comparable to modern automated systems regarding analytical sensitivity and specificity with respect to detection of SARS-CoV-2 as evaluated by RT-qPCR. Moreover, the method is easily scalable and implemented in conventional laboratories as a low cost and suitable alternative to automated systems for the detection of SARS-CoV-2

Verocytotoxin-Producing Escherichia coli in Wild Birds and Rodents in Close Proximity to Farms

Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission

Three-decade epidemiological analysis of <em>Escherichia coli</em> O15:K52:H1

The successful Escherichia coli O15:K52:H1 clonal group provides a case study for the emergence of multiresistant clonal groups of Enterobacteriaceae generally. Accordingly, we tested the hypotheses that, over time, the O15:K52:H1 clonal group has become increasingly (i) virulent and (ii) resistant to antibiotics. One hundred archived international E. coli O15:K52:[H1] clinical isolates from 100 unique patients (1975 to 2006) were characterized for diverse phenotypic and molecular traits. All 100 isolates derived from phylogenetic group D and, presumptively, sequence type ST393. They uniformly carried the F16 papA allele and papG allele II (P fimbria structural subunit and adhesin variants), iha (adhesin-siderophore), fimH (type 1 fimbriae), fyuA (yersiniabactin receptor), iutA (aerobactin receptor), and kpsM II (group 2 capsule); 85% to 89% of them contained a complete copy of the pap operon and ompT (outer membrane protease). Slight additional virulence profile variation was evident, particularly within a minor diarrhea-associated subset (biotype C). However, in contrast to the clonal group's fairly stable virulence profiles over the past 30+ years, during the same interval the clonal group members' antimicrobial resistance profiles increased by a mean of 2.8 units per decade (P < 0.001). Moreover, the numbers of virulence genes and resistance markers were positively associated (P = 0.046), providing evidence against antimicrobial resistance and virulence being mutually exclusive in these strains. Thus, the O15:K52:H1 clonal group has become increasingly resistant to antimicrobials while maintaining (or expanding) its virulence potential, a particularly concerning trend if other emerging multiresistant enterobacterial clonal groups follow a similar pattern