Comparative study of 7 fluorescent pseudomonad clinical isolates

Abstract

There is some debate about the potential survival of Pseudomonas fluorescens at temperatures above 37 degrees C and its consequences for infectious potential, owing to the heterogeneity of clinical strains. Seven clinical strains growing at 37 degrees C or more were submitted for polyphasic identification; 2 were identified as Pseudomonas mosselii and 4 were precisely characterized as P. fluorescens bv. I or II. The binding indexes on glial cells of the strains identified as P. fluorescens bv. I and P. mosselii were compared with that of a reference psychrotrophic strain, P. fluorescens MF37 (bv. V). Clinical P. fluorescens had a similar adherence potential range than strain MF37. Conversely, the binding indexes for P. mosselii strains were 3 times greater than that for strain MF37. These data, and those obtained by comparing the cytotoxic activities of P. fluorescens clinical strains, suggest the existence of different virulence mechanisms, leading either to a low infectious form or to a microorganism with cytotoxic activity in the same range as that of P. mosselii or even Pseudomonas aeruginosa.

Microbiology, Genomics, and Clinical Significance of the Pseudomonas fluorescens Species Complex, an Unappreciated Colonizer of Humans

“…3). Isolates of P. fluorescens derived from nonmammalian samples have a permissive growth range of 4 to 32°C (62), while isolates from humans and other mammals have an elevated upper range extending to 37°C (53,(57)(58)(59). As of the end of 2013, there were 16 fully sequenced strains from the P. fluorescens species complex, and all but one originated from plant surfaces, roots, or the surrounding soil (Table 4).…”

“…For example, we have a collection of over 30 P. fluorescens strains from cystic fibrosis patients that grow well at 37°C. Another study reported a series of P. fluorescens isolates from surface abscess, septicemia, and respiratory or urinary tract infections that were able to grow at 37°C (57). All seven were also able to grow at 4°C, often considered the lower limit of the optimal temperature range of Pseudomonas spp.…”

“…Environmental isolates of P. fluorescens have an optimal temperature growth range of 25 to 30°C and are not virulent to human cells, but certain strains of P. fluorescens isolated from clinical samples have a higher permissive growth range, up to 37°C, and show increased virulence against human cells (53,(57)(58)(59). Two P. fluorescens strains, MFY162 and MFN1032, can adhere to human glial cells in culture, and MFN1032 can induce apoptosis.…”

“…P. fluorescens has been studied most widely as an environmental microbe, most notably for its role in promoting plant health via a number of encoded antimicrobial mechanisms (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38). However, P. fluorescens also possesses a number of functional traits that provide it with the capability to grow and thrive in mammalian hosts, including production of bioactive secondary metabolites (26-30, 33, 39-42), siderophores (43)(44)(45), and a type III secretion system (46)(47)(48)(49)(50)(51), the ability to form biofilms (20,(52)(53)(54)(55)(56), and the plasticity of some strains to adapt to growth at higher temperature (53,(57)(58)(59).…”

Antimicrobial Sensitivity Pattern of Pseudomonas fluorescens after Biofield Treatment

“…P. fluorescens was isolated in bottled water and causing bacteremia and pseudo bacteremia in immunocompromised patients in hospitals from contamination of disinfectants and blood collecting tubes [22]. Although P. fluorescens considered to be non-pathogenic to humans, but recent reports on clinical strains of P. fluorescens have cause serious health problems [23][24][25] which require some alternative treatment approach.…”