Whole-Genome Comparative Analysis of Two Carbapenem-Resistant ST-258<i>Klebsiella pneumoniae</i>Strains Isolated during a North-Eastern Ohio Outbreak: Differences within the High Heterogeneity Zones

Ramírez, María Soledad; Xie, Gary; Traglia, Germán Matías; Johnson, Shannon L.; Davenport, Karen W.; Duin, David van; Ramazani, Azam; Pérez, Federico; Jacobs, Michael; Sherratt, David J.; Chain, Patrick; Tolmasky, Marcelo E.

doi:10.1093/gbe/evw135

Cited by 29 publications

(11 citation statements)

References 33 publications

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“…Klebsiella pneumoniae , although usually carried by healthy humans, is also the causative agent of community- and, more commonly, hospital-acquired infections, accounting for more than 30% of those caused by Gram-negative bacteria (Kalpoe et al, 2012; Shon et al, 2013; Li et al, 2014; Calfee, 2017; Navon-Venezia et al, 2017). K. pneumoniae became more dangerous in recent years due to the acquisition of multidrug resistance (Almaghrabi et al, 2014; Chen et al, 2014a; Ramirez et al, 2016; Rojas et al, 2017b) and the emergence of hypervirulent variants (Decre et al, 2011; Kalpoe et al, 2012; Shon et al, 2013). The most common diseases in Western countries, caused by classic (non-hypervirulent) strains, are urinary tract infections, pneumonia, septicemias, meningitis, and soft tissue infections (Shon et al, 2013; Ramirez et al, 2016; Calfee, 2017; Martel et al, 2017; Gupta et al, 2018; Osman et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Small Klebsiella pneumoniae Plasmids: Neglected Contributors to Antibiotic Resistance

et al. 2019

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Klebsiella pneumoniae is the causative agent of community-and, more commonly, hospital-acquired infections. Infections caused by this bacterium have recently become more dangerous due to the acquisition of multiresistance to antibiotics and the rise of hypervirulent variants. Plasmids usually carry genes coding for resistance to antibiotics or virulence factors, and the recent sequence of complete K. pneumoniae genomes showed that most strains harbor many of them. Unlike large plasmids, small, usually high copy number plasmids, did not attract much attention. However, these plasmids may include genes coding for specialized functions, such as antibiotic resistance, that can be expressed at high levels due to gene dosage effect. These genes may be part of mobile elements that not only facilitate their dissemination but also participate in plasmid evolution. Furthermore, high copy number plasmids may also play a role in evolution by allowing coexistence of mutated and non-mutated versions of a gene, which helps to circumvent the constraints imposed by trade-offs after certain genes mutate. Most K. pneumoniae plasmids 25-kb or smaller replicate by the ColE1-type mechanism and many of them are mobilizable. The transposon Tn1331 and derivatives were found in a high percentage of these plasmids. Another transposon that was found in representatives of this group is the bla KPC-containing Tn4401. Common resistance determinants found in these plasmids were aac(6)-Ib and genes coding for β-lactamases including carbapenemases.

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Section: Introductionmentioning

confidence: 99%

Small Klebsiella pneumoniae Plasmids: Neglected Contributors to Antibiotic Resistance

et al. 2019

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“…This facilitated the discovery of the first opsin-expressing cells in urchins, brittle stars and sea stars, using antibodies subsequently raised against Sp-Op targets [16,26,30], as well as many more opsin sequences in other echinoderms [25,26,31]. Brittle stars, like other echinoderms, possess both rhabdomeric (r-) and ciliary (c-) visual opsins as well as multiple non-visual classes [25,26,32], but exhibit multiple duplications of the rhabdomeric class (closest to Sp-Op4) [26]. These are considered non-visual in most deuterostomes, but are strongly implicated in visual behaviour in both urchins and sea stars [16,33], and sequencing of arm transcriptomes in two brittle stars demonstrated detectable levels of expression of r-opsins similar to Sp-Op4, but not c-opsins, though these were detected at low levels by immunolabelling against Sp-Op1 [25].…”

Section: Introductionmentioning

confidence: 99%

Whole-body photoreceptor networks are independent of ‘lenses’ in brittle stars

et al. 2018

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Photoreception and vision are fundamental aspects of animal sensory biology and ecology, but important gaps remain in our understanding of these processes in many species. The colour-changing brittle star is iconic in vision research, speculatively possessing a unique whole-body visual system that incorporates information from nerve bundles underlying thousands of crystalline 'microlenses'. The hypothesis that these might form a sophisticated compound eye-like system regulated by chromatophores has been extensively reiterated, with investigations into biomimetic optics and similar supposedly 'visual' structures in living and fossil taxa. However, no photoreceptors or visual behaviours have ever been identified. We present the first evidence of photoreceptor networks in three species, both with and without microlenses and colour-changing behaviour. High-resolution microscopy, immunohistochemistry and synchrotron tomography demonstrate that putative photoreceptors cover the animals' oral, lateral and aboral surfaces, but are absent at the hypothesized focal points of the microlenses. The structural optics of these crystal 'lenses' are an exaptation and do not fulfil any apparent visual role. This contradicts previous studies, yet the photoreceptor network in appears even more widespread than previously anticipated, both taxonomically and anatomically.

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“…Far less is known about the expression and function of neuropsin genes relative to r-opsins , particularly outside of the vertebrate lineage [16]. Two of the C. teleta neuropsin genes, Ct-n-opsin2 and Ct-n-opsin3 , are expressed in a small subset of cells in the brain region.…”

Section: Discussionmentioning

confidence: 99%

“…The cerebral eyes in larval and adult polychaetes typically have rhabdomeric photoreceptor cells, although there are exceptions [3,4,15]. In the last common ancestor of bilaterians, nine classes of opsin genes were thought to have been present [16]. The genome of C. teleta contains nine opsin genes that belong to only two opsin classes: three rhabdomeric opsin ( r-opsin) and six neuropsin genes [16,17].…”

Section: Introductionmentioning

confidence: 99%

“…In the last common ancestor of bilaterians, nine classes of opsin genes were thought to have been present [16]. The genome of C. teleta contains nine opsin genes that belong to only two opsin classes: three rhabdomeric opsin ( r-opsin) and six neuropsin genes [16,17]. Notably, C. teleta lacks ciliary opsin genes; a similar situation is found in most other lophotrochozoans [16].…”

Section: Introductionmentioning

confidence: 99%

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CRISPR/CAS9 mutagenesis of a single r-opsin gene blocks phototaxis in a marine larva

2019

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Many marine animals depend upon a larval phase of their life cycle to locate suitable habitat, and larvae use light detection to influence swimming behaviour and dispersal. Light detection is mediated by the opsin genes, which encode light-sensitive transmembrane proteins. Previous studies suggest that r-opsins in the eyes mediate locomotory behaviour in marine protostomes, but few have provided direct evidence through gene mutagenesis. Larvae of the marine annelid Capitella teleta have simple eyespots and are positively phototactic, although the molecular components that mediate this behaviour are unknown. Here, we characterize the spatio-temporal expression of the rhabdomeric opsin genes in C. teleta and show that a single rhabdomeric opsin gene, Ct-r-opsin1 , is expressed in the larval photoreceptor cells. To investigate its function, Ct-r-opsin1 was disrupted using CRISPR/CAS9 mutagenesis. Polymerase chain reaction amplification and DNA sequencing demonstrated efficient editing of the Ct-r-opsin1 locus. In addition, the pattern of Ct-r-opsin1 expression in photoreceptor cells was altered. Notably, there was a significant decrease in larval phototaxis, although the eyespot photoreceptor cell and associated pigment cell formed normally and persisted in Ct-r-opsin1 -mutant animals. The loss of phototaxis owing to mutations in Ct-r-opsin1 is similar to that observed when the entire photoreceptor and pigment cell are deleted, demonstrating that a single r-opsin gene is sufficient to mediate phototaxis in C. teleta . These results establish the feasibility of gene editing in animals like C. teleta , and extend previous work on the development, evolution and function of the C. teleta visual system . Our study represents one example of disruption of animal behaviour by gene editing through CRISPR/CAS9 mutagenesis, and has broad implications for performing genome editing studies in a wide variety of other understudied animals.

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Whole-Genome Comparative Analysis of Two Carbapenem-Resistant ST-258Klebsiella pneumoniaeStrains Isolated during a North-Eastern Ohio Outbreak: Differences within the High Heterogeneity Zones

Cited by 29 publications

References 33 publications

Small Klebsiella pneumoniae Plasmids: Neglected Contributors to Antibiotic Resistance

Small Klebsiella pneumoniae Plasmids: Neglected Contributors to Antibiotic Resistance

Whole-body photoreceptor networks are independent of ‘lenses’ in brittle stars

CRISPR/CAS9 mutagenesis of a single r-opsin gene blocks phototaxis in a marine larva

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