Summary of Transporters Involved in Virulence or Toxin and Drug Efflux.

<p>Transporters involved in virulence are in bold.</p

The basic characteristics of the more frequently used model hosts.

<p>The blue color indicates that this feature is found in the specific model host. Utilizing the features of the chart can aid in determining which host(s) are most amenable to a particular study. Host genetic tools aiding in understanding host–pathogen interaction include sequenced genomes, available mutant strains, or RNAi. Once infected, some hosts can be used to identify compounds with antifungal activity. Also, while infected, some hosts are large enough that individual portions or tissues from the hosts can be removed and further analyzed either for host responses or to evaluate tissue invasion by the pathogen. As part of the host response, some hosts have phagocytic cells that engulf the foreign fungi and can be studied to elucidate information about host–pathogen interactions. When some fungi are engulfed by phagocytes, or establish an infection within the hosts, they produce hyphae. Because of the transparency or ability to recover tissue from some of the hosts, fungal hyphae formation can be further evaluated. For all of the infecting pathogens, temperature conditions are a consideration. The various hosts have conditions that are ideal for meeting their own survival needs, and the fungi will react differently in terms of gene expression and growth rate based on the temperatures in which the hosts are maintained. Temperature features marked in grey on the chart indicate hosts that can survive at temperature ranges as high as 37°C. Other invertebrate model hosts including <i>Bombyx mori</i>, <i>Culex quinquefasciatus</i>, <i>Blattella germanica</i>, and even a plant model of <i>Arabidopsis thaliana</i> have been developed. They are not as widely used and not mentioned here in detail because of space limitations.</p

Summary of findings generated by using the invertebrate infection models.

<p>Summary of findings generated by using the invertebrate infection models.</p

Dead C. elegans Nematodes Infected by C. albicans

<p>Filamentation is instrumental for <i>Candida</i> virulence in mammals and is also involved in the killing of C. elegans [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.0030101#ppat-0030101-b020" target="_blank">20</a>]. The four panels show consequences of infecting <i>C. elegans glp-4;sek-1</i> animals with C. albicans and then moving them into pathogen-free liquid medium. The top panels show that C. albicans cells persist within the C. elegans intestine and form hyphae (green) that break through the C. elegans cuticle, leaving a C. elegans “ghost” (dark structure) that outlines where the cuticle used to be. The bottom panels show that <i>Candida</i> cells develop filaments (green) that differentiate into hyphae, long continuous germ tubes separated by true septin rings, or pseudohyphae, chains of distinct cells that fail to separate. Pictures were taken with a confocal laser microscope (TCS NT; Leica Microsystems, <a href="http://www.leica-microsystems.com/" target="_blank">http://www.leica-microsystems.com/</a>). Concanavalin A-Alexafluor (fluorescence emission at 519 nm) is a fluorescent green dye that binds to polysaccharides. FUN-1, which was also used in the bottom right panel, is a fluorescent yellow dye that is absorbed by metabolically active fungal cells and fluoresces red when illuminated with a fluorescence emission 480 nm [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.0030101#ppat-0030101-b020" target="_blank">20</a>].</p

Wild-Type C. neoformans Accumulates in the Gastrointestinal Tract

<p>Intact yeast cells are present in the distended (A) proximal and (B) distal gastrointestinal tract of C. elegans after feeding for 36 h on C. neoformans strain KN99α. Black arrows point to the intestinal lumen. The white arrowheads note the pharyngeal grinder organ, which functions to disrupt ingested organisms.</p

The morphology of two tested <i>P. marneffei</i> strains after 7 days of incubation at 25°C and 37°C (a).

<p>Survival curves of <i>C. elegans</i> after infected with <i>P. marneffei</i> in solid medium (b) and liquid medium (c).</p

Prevalence of ESBL-Producing Enterobacteriaceae in Pediatric Bloodstream Infections: A Systematic Review and Meta-Analysis - Fig 2

<p><b>Prevalence of ESBL-PE among laboratory-confirmed bloodstream infections in pediatric patients:</b> forest plot of included studies and geographical distribution.</p

Progression of red pigment in the <i>C. elegans</i> intestine.

<p>Microscopy of wild-type <i>C. elegans</i> N2 at different time points after infected with <i>P. marneffei</i> strain 570 or 486. Red pigment was seen in the <i>C. elegans</i> swelling intestine and increased gradually with time after infected with live <i>P. marneffei</i> strain 570 (a). No obvious swelling or red pigment was seen in the <i>C. elegans</i> intestine after infected with live <i>P. marneffei</i> strain 486 (b).</p

Antifungal agents prolong the survival of wild-type <i>C. elegans</i> N2 infected by <i>P. marneffei</i> 570.

<p>Significant differences were found between 570 infected group and all the administration groups (<i>P</i><0.001).</p

PRISMA flow diagram.

<p>PRISMA flow diagram.</p