Changes in diversity of cultured bacteria resistant to erythromycin and tetracycline in swine manure during simulated composting and lagoon storage

This study investigated the impact of composting and lagoon storage on survival and change in diversity of tetracycline-resistant (Tc(r) ) and erythromycin-resistant (Em(r) ) bacteria and the resistance genes they carry in swine manure. Treatments were arranged as a 2 × 2 factorial design: composting vs lagoon storage and 0 vs 1% Surround WP Crop Protectant (a clay product) in three replicates. After 48 days of treatments, resistant bacteria were enumerated by selective plating and identified by 16S rRNA gene sequencing. The erm and the tet gene(s) carried by the resistant isolates were screened using class-specific PCR assays. The plate counts of Tc(r) and Em(r) bacteria decreased by 4-7 logs by composting, but only by 1-2 logs by the lagoon treatment. During the treatments, Acinetobacter gave way to Pseudomonas and Providencia as the largest resistant genera. The clay product had little effect on survival or diversity of resistant bacteria. Of six classes of erm and seven classes of tet genes tested, changes in prevalence were also noted. The results indicate that composting can dramatically shift Tc(r) and Em(r) bacterial populations, and composting can be an effective and practical approach to decrease dissemination of antibiotic resistance from swine farms to the environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presented research provided evidence that composting is much more effective than lagoon storage in dramatically decreasing culturable bacteria resistant to erythromycin and tetracycline in swine manure. Considerable diversity changes of resistant bacteria were also demonstrated during composting or lagoon storage. Overall, Acinetobacter was the major resistant genus in untreated swine manure, but pseudomonads and Providencia became the major resistant genera after the treatments. This is the first study that investigated diversity changes of cultured bacteria resistant to these two antibiotics during composting and lagoon storage of swine manure. New genes encoding resistance to the two antibiotics were also implied in the cultured isolates.

Abundance of pathogens in the gut and litter of broiler chickens as affected by bacitracin and litter management

Clostridium perfringens, Salmonella spp. and Campylobacter spp. are food-borne enteric pathogens that are commonly associated with poultry. The objective of this study was to investigate the effects of supplemental bacitracin and litter management (fresh vs. reused) on the abundance of these pathogens in commercial broiler chickens. Specific quantitative PCR (qPCR) assays were used to quantify C. perfringens, virulent C. perfringens that carried the genes encoding α-toxin (cpa) and NetB-toxin (netB), Salmonella, and Campylobacter in samples of ileal mucosa, cecal content, and litter. Campylobacter was not detected in any of the samples collected. The abundance of Salmonella was not affected by either bacitracin or litter condition. Generic C. perfringens was detected in the ileal mucosa at very low level at 10 days of age but was much higher at 35 days. Chickens reared on reused litter tended to have a lower abundance of generic C. perfringens compared with those reared on fresh litter. In the ileal mucosa, no cpa or netB was detected at day 10 but was detected at day 35 in the chickens that were not fed supplemental bacitracin. Chicks fed supplemental bacitracin had reduced abundance of generic C. perfringens as well as the cpa and netB genes in the ileal mucosa, cecal content, and litters. A strong positive correlation was found between the abundance of all three measurements of C. perfringens. The abundance of Salmonella spp. and C. perfringens was also shown to be correlated. This is the first study that has examined the effect of dietary bacitracin and litter conditions on the prevalence of these three common enteric pathogens. Unless contaminated from previous flocks, reused litter may not necessarily contain significantly greater abundances of C. perfringens or Salmonella.

Evolution of weedy giant ragweed (Ambrosia trifida): Multiple origins and gene expression variability facilitates weediness

Agricultural weeds may originate from wild populations, but the origination patterns and genetics underlying this transition remain largely unknown. Analysis of weedy-wild paired populations from independent locations may provide evidence to identify key genetic variation contributing to this adaptive shift. We performed genetic variation and expression analyses on transcriptome data from 67 giant ragweed samples collected from different locations in Ohio, Iowa, and Minnesota and found geographically separated weedy populations likely originated independently from their adjacent wild populations, but subsequent spreading of weedy populations also occurred locally. By using eight closely related weedy-wild paired populations, we identified thousands of unique transcripts in weedy populations that reflect shared or specific functions corresponding, respectively, to both convergently evolved and population-specific weediness processes. In addition, differential expression of specific groups of genes was detected between weedy and wild giant ragweed populations using gene expression diversity and gene co-expression network analyses. Our study suggests an integrated route of weedy giant ragweed origination, consisting of independent origination combined with the subsequent spreading of certain weedy populations, and provides several lines of evidence to support the hypothesis that gene expression variability plays a key role in the evolution of weedy species.

Collaboration of an Obstetrical Residency Program With a Community Hospice/Bereavement Agency to Implement an Obstetrician Specific Educational Curriculum to Improve Care to Bereaved Families and Support Staff During Difficult Delivery Situations

Obstetricians face significant emotional and professional challenges caring for pregnant women experiencing fetal life-limiting diagnoses or fetal demise. Many physicians are uncomfortable offering the emotional support parents need during an unexpected end-of-life neonatal situation. Physicians who deliver life-changing bad news to families experience significant emotional and physical stress. We conducted an obstetrician needs assessment documenting interest in an educational curriculum that could enhance physician comfort and competency in communication skills; particularly for fetal abnormalities, challenging deliveries with poor outcomes, providing condolences to bereaved families and supporting colleagues after adverse outcomes. Patient-centered care requires prioritizing the needs and autonomy of each patient. Ensuring patients receive comprehensive informed consent regarding fetal diagnosis/prognosis and all available treatment options including continuing the pregnancy, termination, compassionate induction based on gestational age and personal wishes in cases of life-limiting fetal diagnoses , and delivery options including labor induction vs dilation and evacuation (D&E) is essential. We identified significant barriers. Some providers were reluctant to present termination as an option for life-limiting fetal diagnosis before 24 weeks of gestation. Many residents and faculty lacked sufficient training in the D&E procedure. The COVID-19 pandemic had disrupted essential hospital support resources. Our obstetrics residency program implemented a joint quality improvement initiative and educational research study. We collaborated with a community perinatal hospice/bereavement support organization to develop an obstetrician educational curriculum. We emphasized teamwork and consistency in delivering parent-centered bereavement care and support. To our knowledge, no similar program specific to an obstetrical residency program has been previously published.

Assessment tool items for addressing physician-patient communication and reducing health care risk factors across multiple enterprise risk management domains

Expertise in physician-patient communication is a primary outcome measure for physicians. We evaluated residents' communication behaviors with clinic patients following an educational intervention as measured by the Communication Assessment Tool (CAT). Thirty-five internal medicine residents were assessed by patients using the CAT for 3 months before and after the educational intervention. The intervention included a simulated, videotaped patient encounter, mock CAT, and preceptor coaching during video review. The primary outcome was the percentage of CAT items receiving an "excellent" rating from patients before and after the intervention. Research results were compared to previously published CAT studies. Within-resident improvement in the percentage of excellent ratings was small with median changes between 0 and 3 percentage points. Compared to previously published studies, similar results were found for the highest and lowest-scored communication items. Many clinical encounters are time-limited, and physicians do not pursue time-consuming conversations that could reduce health care risk. This data and other published studies suggest seven communication items taking the most time to complete (i.e., shared decision-making) were items demonstrating little or no improvement. This study identified clinical performance risk factors applicable to the Enterprise Risk Management Framework that could impact complication and readmission rates if addressed by changes in physician-patient communication.