“We Stretch Our Limits and Change Our Lives”: Interspecies Communication in Contemporary American Pet Memoirs

2018 ◽  
pp. 105-121





2006 ◽  
Vol 73 (2) ◽  
pp. 650-654 ◽  
Author(s):  
Christophe Dubuis ◽  
Dieter Haas

ABSTRACT Signal extracts prepared from culture supernatants of Pseudomonas fluorescens CHA0 and Pseudomonas aeruginosa PAO stimulated GacA-dependent expression of small RNAs and hence of antibiotic compounds in both hosts. Pseudomonas corrugata LMG2172 and P. fluorescens SBW25 also produced signal molecules stimulating GacA-controlled antibiotic synthesis in strain CHA0, illustrating a novel, N-acyl-homoserine lactone-independent type of interspecies communication.





2015 ◽  
Vol 9 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Stephen J Smith

The art of riding imagines the human-horse relation in the image of the centaur. In synchronous motions, riding is a dance of sorts, contact of bodies in the skin of the moment. Yet always there is the possibility of fussing, flailing, falling and failing in moments of resistance, evasion and contrariness. Through phenomenological reflection on such moments, riding can be understood not simply in terms of its difficulties of centaurian mastery, but in terms of the postural, positional, gestural, expressive nuances of interspecies communication. It is on the off beats, and within the syncopations and momentary stresses of riding, that resistance can be addressed through quiet insistence, evasions overcome through persuasion, and contrariness can be felt otherwise. Through contemplation of such moments, we find the reminders of a sensual and essential intercorporeality and the configuration of an agogic practice.



Public ◽  
2019 ◽  
Vol 30 (59) ◽  
pp. 4-13
Author(s):  
Meredith Tromble


mBio ◽  
2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Laura C. Cook ◽  
Breah LaSarre ◽  
Michael J. Federle

ABSTRACTQuorum sensing (QS) regulates diverse and coordinated behaviors in bacteria, including the production of virulence factors, biofilm formation, sporulation, and competence development. It is now established that some streptococci utilize Rgg-type proteins in concert with short hydrophobic peptides (SHPs) to mediate QS, and sequence analysis reveals that several streptococcal species contain highly homologous Rgg/SHP pairs. In group A streptococcus (GAS), two SHPs (SHP2 and SHP3 [SHP2/3]) were previously identified to be important in GAS biofilm formation. SHP2/3 are detected by two antagonistic regulators, Rgg2 and Rgg3, which control expression of theshpgenes. In group B streptococcus (GBS), RovS is a known virulence gene regulator and ortholog of Rgg2, whereas no apparent Rgg3 homolog exists. Adjacent torovSis a gene (shp1520) encoding a peptide nearly identical to SHP2. Using isogenic mutant strains and transcriptional reporters, we confirmed that RovS/SHP1520 comprise a QS circuit in GBS. More important, we performed experiments demonstrating that production and secretion of SHP1520 by GBS can modulate Rgg2/3-regulated gene expression in GAS intrans; likewise, SHP2/3 production by GAS can stimulate RovS-mediated gene regulation in GBS. An isolate ofStreptococcus dysgalactiaesubsp.equisimilisalso produced a secreted factor capable of simulating the QS circuits of both GAS and GBS, and sequencing confirms the presence of an orthologous Rgg2/SHP2 pair in this species as well. To our knowledge, this is the first documented case of bidirectional signaling between streptococcal species in coculture and suggests a role for orthologous Rgg/SHP systems in interspecies communication between important human pathogens.IMPORTANCEPathogenic streptococci, such as group A (GAS) and group B (GBS) streptococcus, are able to persist in the human body without causing disease but become pathogenic under certain conditions that are not fully characterized. Environmental cues and interspecies signaling between members of the human flora likely play an important role in the transition to a disease state. Since quorum-sensing (QS) peptides have been consistently shown to regulate virulence factor production in pathogenic species, the ability of bacteria to signal via these peptides may prove to be an important link between the carrier and pathogenic states. Here we provide evidence of a bidirectional QS system between GAS, GBS, andStreptococcus dysgalactiaesubsp.equisimilis, demonstrating the possibility of evolved communication systems between human pathogens.



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