15 research outputs found

    Genomic characterization of emerging bacterial uropathogen Neisseria meningitidis, which was misidentified as Neisseria gonorrhoeae by nucleic acid amplification testing

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    Neisseria meningitidis and Neisseria gonorrhoeae are pathogenic bacteria that can cause human infections. While N. meningitidis infections are associated with bacterial meningitis and bacteremia, a strain of N. meningitidis, isolated from the urogenital system, has recently been associated with urethritis. As this strain is becoming prominent as an emerging pathogen, it is essential to assess identification tools for N. meningitidis and N. gonorrhoeae urogenital isolates. Consecutive N. meningitidis isolates recovered from urogenital cultures of symptomatic patients with presumptive diagnoses of gonorrhea and a random selection of N. gonorrhoeae isolates recovered from the same population within the same time frame were characterized with routine identification systems, antimicrobial susceptibility testing, and whole-genome sequencing. Matrix-assisted laser desorption ionization鈥搕ime of flight mass spectrometry (MALDI-TOF MS), multilocus sequence typing, 16S rRNA gene sequence, and average nucleotide identity methods accurately identified 95% (18/19) of N. meningitidis and N. gonorrhoeae isolates. With the Aptima Combo 2 CT/NG test, 30% (3/10) of N. meningitidis isolates were misidentified as N. gonorrhoeae, but no misidentifications were found with the Xpert CT/NG nucleic acid amplification test (NAAT). Phylogenetic core genome and single nucleotide polymorphism (SNP)-based grouping analyses showed that urogenital N. meningitidis isolates were highly related and phylogenetically distinct from N. gonorrhoeae and respiratory N. meningitidis isolates but similar to urogenital N. meningitidis isolates from patients with urethritis in the United States. Urogenital N. meningitidis isolates were predominantly azithromycin resistant, while N. gonorrhoeae isolates were azithromycin susceptible. These data indicate that urogenital isolates of N. meningitidis can cause false-positive detections with N. gonorrhoeae diagnostic assays. Misidentification of urogenital N. meningitidis isolates may confound public health-related activities for gonorrhea, and future studies are needed to understand the impact on clinical outcome of N. meningitidis urogenital infection

    Manure microbial communities and resistance profiles reconfigure after transition to manure pits and differ from those in fertilized field soil

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    In agricultural settings, microbes and antimicrobial resistance genes (ARGs) have the potential to be transferred across diverse environments and ecosystems. The consequences of these microbial transfers are unclear and understudied. On dairy farms, the storage of cow manure in manure pits and subsequent application to field soil as a fertilizer may facilitate the spread of the mammalian gut microbiome and its associated ARGs to the environment. To determine the extent of both taxonomic and resistance similarity during these transitions, we collected fresh manure, manure from pits, and field soil across 15 different dairy farms for three consecutive seasons. We used a combination of shotgun metagenomic sequencing and functional metagenomics to quantitatively interrogate taxonomic and ARG compositional variation on farms. We found that as the microbiome transitions from fresh dairy cow manure to manure pits, microbial taxonomic compositions and resistance profiles experience distinct restructuring, including decreases in alpha diversity and shifts in specific ARG abundances that potentially correspond to fresh manure going from a gut-structured community to an environment-structured community. Further, we did not find evidence of shared microbial community or a transfer of ARGs between manure and field soil microbiomes. Our results suggest that fresh manure experiences a compositional change in manure pits during storage and that the storage of manure in manure pits does not result in a depletion of ARGs. We did not find evidence of taxonomic or ARG restructuring of soil microbiota with the application of manure to field soils, as soil communities remained resilient to manure-induced perturbation

    Acute and persistent effects of commonly used antibiotics on the gut microbiome and resistome in healthy adults

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    Antibiotics are deployed against bacterial pathogens, but their targeting of conserved microbial processes means they also collaterally perturb the commensal microbiome. To understand acute and persistent effects of antibiotics on the gut microbiota of healthy adult volunteers, we quantify microbiome dynamics before, during, and 6 months after exposure to 4 commonly used antibiotic regimens. We observe an acute decrease in species richness and culturable bacteria after antibiotics, with most healthy adult microbiomes returning to pre-treatment species richness after 2 months, but with an altered taxonomy, resistome, and metabolic output, as well as an increased antibiotic resistance burden. Azithromycin delays the recovery of species richness, resulting in greater compositional distance. A subset of volunteers experience a persistent reduction in microbiome diversity after antibiotics and share compositional similarities with patients hospitalized in intensive care units. These results improve our quantitative understanding of the impact of antibiotics on commensal microbiome dynamics, resilience, and recovery

    BBE355369.indd

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    gests that a reduced visual system evolved with the origins of an active electrosense, and that this one particular lineage secondarily evolved an enlarged visual system. Behavioral tests revealed that this enlargement of the visual system established increased visual acuity. Thus, our findings demonstrate that different lineages of mormyrids have evolved visual or electrosensory specializations, but that no lineages have specialized in both. This sensory divergence likely reflects fundamentally different ecologies and suggests that vision may play an especially important role in the social behavior of mormyrids that cannot detect variation in electric signal waveform. Our findings provide an example of evolutionary change in multiple sensory systems among closely related species that lays a foundation for relating ecological adaptation to evolutionary change in multisensory perception and social behavior. Introduction Sensory systems can evolve in response to selection arising from a variety of biotic and abiotic factors. In extreme cases, differences between the environments of closely related species can lead to lineage-specific sensory Key Words Mormyrids 路 Electric fishes 路 Electrosensory system 路 Exterolateral nucleus 路 Visual acuity 路 Optic tectum 路 Optomotor response Abstract African mormyrid fishes are by far the most diverse group of osteoglossomorph (bony tongue) fishes. Mormyrids communicate using pulses of electricity, and they process electric communication signals in the midbrain exterolateral nucleus (EL). In its ancestral form, the EL is relatively small and homogenous. In two different lineages, however, the EL expanded in size and increased in cytological complexity. This evolutionary change established the perceptual ability to distinguish variation in electric pulse waveform, which plays an important role in species recognition and mate choice. However, the sensory basis of social behavior in species with a small, homogenous EL remains unknown. Using published species descriptions, we found that species in one of these lineages have relatively large eyes. Using sectioned brains, we measured the volume of a major visual region, the optic tectum (OT), and found that this same lineage also has an enlarged OT. We also found that eye size and OT size are highly correlated across species. Phylogenetic analysis sug

    Sukhum_Energeticcostsdata

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    This file contains all the raw data, including dissection weights, behavior videos, and EOD recordings, as well as all R code for analyses used in the paper
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