Swine are known reservoirs for Clostridioides difficile, formerly known as Clostridium difficile, and transmission from swine to human farm workers is strongly suggested by previous studies. This ...cross‐sectional study evaluated the potential role of farm environmental surfaces, including those in worker breakrooms and swine housing areas, in the possible transmission of C. difficile from swine to farm workers. Environmental surfaces and piglet faeces at 13 Ohio swine farms were sampled in 2015. Typical culturing techniques were performed to isolate C. difficile from samples, and amplification of toxin genes (tcdA, tcdB and cdtB) and PCR‐ribotyping were used to genetically characterize recovered isolates. In addition, sequencing of toxin regulatory gene, tcdC, was done to identify the length of identified deletions in some isolates. A survey collected farm‐level management risk factor information. Clostridioides difficile was recovered from all farms, with 42% (188/445) of samples testing positive for C. difficile. Samples collected from all on‐farm locations recovered C. difficile, including farrowing rooms (60%, 107/178), breakrooms (50%, 69/138) and nursery rooms (9%, 12/129). Three ribotypes recovered from both swine and human environments (078, 412 and 005) have been previously implicated in human disease. Samples taken from farrowing rooms and breakrooms were found to have greater odds of C. difficile recovery than those taken from nursery rooms (OR = 40.5, OR = 35.6, p < .001 respectively). Farms that weaned ≥23,500 pigs per year had lower odds of C. difficile recovery as compared to farms that weaned fewer pigs (OR = 0.4, p = .01) and weekly or more frequent cleaning of breakroom counters was associated with higher odds of C. difficile recovery (OR = 11.7, p < .001). This study provides important insights into the presence and characterization of C. difficile found in human environments on swine farms and highlights how these areas may be involved in transmission of C. difficile to swine farm workers and throughout the facility.
Next-generation sequencing (NGS) has revolutionized molecular systematics as well as population and conservation genetics. It is now possible to obtain enormous amounts of gene sequence data from any ...species in a short time at low cost. More technological advances are on the horizon, ensuring that this trend will continue throughout the coming decade. These rapid advances provide unprecedented opportunities in systematics; they also pose new challenges, requiring that the next generation of systematists be well-versed in new skill sets (e.g., bioinformatics). As examples of the potential of NGS, it is now possible to develop genetic resources for any plant system that poses intriguing evolutionary questions. During the next decade many new “evolutionary model systems” will become available as systematists rapidly develop the necessary genetic/genomic frameworks for many previously unstudied plants. Phylogenetic reconstruction will be conducted at an unprecedented pace at both deep and fine scales with datasets of numerous taxa and genes—this includes rapid progress on assembling a more comprehensive Tree of Life for green plants. For example, complete plastid genome sequencing is now routinely facilitating analyses of hundreds of taxa at deep levels, as well as enabling complete plastid genome phylogeographic analyses at the population level. Gene capture methods hold enormous promise for the rapid and inexpensive analyses of complete plastid genomes, as well as studies of hundreds of selected (targeted) nuclear loci. NGS has also had a big impact on population genetics, initially by dramatically simplifying microsatellite marker development, but more recently by opening new possibilities through various genotyping-by-sequencing (GBS) approaches that have great potential to expand on the types of questions that can be addressed at the population level. Transcriptome sequencing has enabled the construction of large datasets of nuclear genes while also providing a wealth of plastid and mitochondrial genes. NGS has also facilitated probe development for studies of chromosomes using FISH (fluorescence in situ hybridization). NGS is also making the rapid sequencing of complete nuclear genomes routine, thus transforming our field and opening up new avenues of systematic endeavor in comparative genomics. However, even as sequencing costs drop and technological advances make complete nuclear genome sequencing more commonplace, genome assembly will remain a major challenge.
Effective Haemophilus influenzae type b (Hib) conjugate vaccines were first licensed for use in US children at least 18 months old in December 1987 and for infants at least 2 months old in October ...1990. We evaluated trends in Hib disease associated with licensure of Hib conjugate vaccines.
Data from two sources, an intensive laboratory-based active surveillance system and the National Bacterial Meningitis Reporting System (NBMRS), were used separately to evaluate disease incidence. Data from vaccine manufacturers on Hib vaccine doses distributed in the United States were compared with trends in Hib disease incidence.
The age-specific incidence of Hib disease among children less than 5 years old decreased by 71% from 37 per 100,000 persons in 1989 to 11 per 100,000 persons in 1991 (active surveillance data). Haemophilus influenzae meningitis incidence decreased by 82% between 1985 and 1991 (NBMRS data). Increases in doses of Hib vaccine distributed in the United States coincided with steep declines in Hib disease. Both surveillance systems showed decreased rates of Hib disease in infants less than 1 year old before vaccine was licensed for use in this age group. Haemophilus influenzae type b disease incidence in persons at least 12 years old and pneumococcal meningitis incidence in children less than 5 years old did not change substantially during the same period; therefore, decreased Hib disease in children less than 5 years old is not likely to be explained solely by changes in surveillance sensitivity or decreases in bacterial disease due to changes in medical practice.
Our data suggest that conjugate vaccines have already had a marked impact on the incidence of Hib disease in the United States, preventing an estimated 10,000 to 16,000 cases of Hib disease in 1991. The decline of disease in infants less than 1 year old before licensure for this age group warrants further investigation.
Objective. To identify dietary risk factors for sporadic listeriosis. Design. Case-control study with blinded telephone interviews. Setting. Multistate population of 18 million persons, November 1988 ...through December 1990. Participants. One hundred sixty-five patients with culture-confirmed listeriosis and 376 control subjects matched for age, health care provider, and immunosuppressive condition. Results. The annual incidence of invasive listeriosis was 7.4 cases per million population; 23% of the infections were fatal. Cases were more likely than matched controls to have eaten soft cheeses (odds ratio OR, 2.6; 95% confidence interval CI, 1.4 to 4.8; P = 0.002) or food purchased from store delicatessen counters (OR, 1.6; 95% CI, 1.0 to 2.5; P = 0.04); 32% of sporadic disease could be attributed to eating these foods. Sixty-nine percent of cases in men and nonpregnant women occurred in cancer patients, persons with the acquired immunodeficiency syndrome, organ transplant recipients, or those receiving corticosteroid therapy. Among these immunosuppressed patients, eating undercooked chicken also increased the risk of listeriosis (OR, 3.3; 95% CI, 1.2 to 9.2; P = 0.02). Conclusions. Foodborne transmission may account for a substantial portion of sporadic listeriosis. Prevention efforts should include dietary counseling of high-risk patients and continued monitoring of food production
Increasing circuit complexity within quantum systems based on superconducting qubits necessitates high connectivity while retaining qubit coherence. Classical micro-electronic systems have addressed ...interconnect density challenges by using 3D integration with interposers containing through-silicon vias (TSVs), but extending these integration techniques to superconducting quantum systems is challenging. Here, we discuss our approach for realizing high-aspect-ratio superconducting TSVs\textemdash 10 \(\mu\)m wide by 20 \(\mu\)m long by 200 \(\mu\)m deep\textemdash with densities of 100 electrically isolated TSVs per square millimeter. We characterize the DC and microwave performance of superconducting TSVs at cryogenic temperatures and demonstrate superconducting critical currents greater than 20 mA. These high-aspect-ratio, high critical current superconducting TSVs will enable high-density vertical signal routing within superconducting quantum processors.
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