b Laminated, microbially produced stromatolites within the rock record provide some of the earliest evidence for life on Earth. The chemical, physical, and biological factors that lead to the initiation of these organosedimentary structures and shape their morphology are unclear. Modern coniform structures with morphological features similar to stromatolites are found on the surface of cyanobacterial/microbial mats. They display a vertical element of growth, can have lamination, can be lithified, and observably grow with time. To begin to understand the microbial processes and interactions required for cone formation, we determined the phylogenetic composition of the microbial community of a coniform structure from a cyanobacterial mat at Octopus Spring, Yellowstone National Park, and reconstituted coniform structures in vitro. The 16S rRNA clone library from the coniform structure was dominated by Leptolyngbya sp. Other cyanobacteria and heterotrophic bacteria were present in much lower abundance. The same Leptolyngbya sp. identified in the clone library was also enriched in the laboratory and could produce cones in vitro. When coniform structures were cultivated in the laboratory, the initial incubation conditions were found to influence coniform morphology. In addition, both the angle of illumination and the orientation of the surface affected the angle of cone formation demonstrating how external factors can influence coniform, and likely, stromatolite morphology.
V erona-integron-encoded metallo-β-lactamaseproducing carbapenem-resistant Pseudomonas aeruginosa (VIM-CRPA) and other carbapenemaseproducing organisms (CPOs) are emerging public health threats. CPOs cause infections that are often extensively drug-resistant and associated with substantial rates of illness and death. By colonizing faucet aerators and wastewater plumbing systems, CPOs can spread rapidly within healthcare facilities, including to patients (1-9). VIM is a carbapenemase, a type of enzyme that inactivates carbapenems and other β-lactam antimicrobial drugs that are frequently encoded on mobile genetic elements, which in turn can lead to horizontal spread. VIM-CRPA is uncommon in the United States; <150 isolates are reported to CDC annually (10). During June 2017-November 2019, in a city of 250,000 residents in western Texas, USA (city A), 36 patients with VIM-CRPA were identified. Most were hospitalized for >1 night at an acute-care hospital (hospital A) in the 6 months before VIM-CRPA was isolated, but patients did not have overlapping hospital stays or common procedures. We assessed water sources and plumbing in hospital A to identify potential VIM-CRPA reservoirs.Beginning in June 2017, the Texas Department of State Health Services asked clinical laboratories to voluntarily submit clinical P. aeruginosa isolates resistant to imipenem, meropenem, or doripenem to the Texas Department of State Health Services Laboratory for mechanism testing through the Antibiotic Resistance Laboratory Network (https:// www.cdc.gov/drugresistance/ar-lab-networks/ domestic.html). The 2 clinical laboratories that served hospitals in city A began submitting all CRPA for mechanism testing in June 2017 (hospital A) and April 2018 (hospital B). During July 2017-January 2019, a total of 36 patients with VIM-CRPA isolated from clinical cultures were identified from city laboratories; 21 (58%) had been admitted to hospital A for >1 night in the 6 months before culture collection.We reviewed medical records from hospital A of patients with VIM-CRPA. Median patient age was 57 (range 9-84) years; 57% were male. VIM-CRPA was isolated from wounds in 9 (43%) patients, respiratory sources in 7 (33%), and urine in 5 (24%). Most patients primarily received care on
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