Escherichia coli interactions with Acanthamoeba: a symbiosis with environmental and clinical implications

Alsam, Selwa; Jeong, Seok Ryoul; Sissons, James; Dudley, Ricky; Kim, Kwang Sik; Khan, Naveed Ahmed

doi:10.1099/jmm.0.46497-0

Cited by 92 publications

(85 citation statements)

References 19 publications

(19 reference statements)

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“…pneumoniae, E. aerogenes, R. terrigena, and R. ornitholytica. Previous data demonstrated that Enterobacteriaceae can survive and multiply within amoeba host [23,[35][36][37][38][39] which is consistent with our findings. At 48h co-incubation, the intracellular counts for all bacteria in our study decreased onwards.…”

Section: Co-culture Of a Spelaea And Bacteriasupporting

confidence: 93%

Allovahlkampfia spelaea is a Potential Environmental Host for Pathogenic Bacteria

Mohamed¹,

Huseein²,

Farrag³

et al. 2016

J Bacteriol Parasitol

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Allovahlkampfia spelaea was identified for the first time in 2009. As a free living amoeba, it has been suggested to be a protective host for some bacterial pathogens against harsh environmental conditions and can transmit them to vulnerable hosts. We aimed in this study to test the interactions between Allovahlkampfia spelaea and some waterborne and foodborne bacteria and unravel if the tested bacteria can survive and multiply inside amoeba. We used a keratitis isolate of Allovahlkampfia spelaea grown in PYG medium containing proteose peptone, yeast extracts, and glucose. We examined amoeba interactions with Methicillin resistant Staphylococcus aureus, Escherichia coli 1, Klebsiella pneumoniae, Enterobacter aerogenes, Citrobacter cloaca, Proteus mirabilis, Raoultella terrigena, Raoultella ornitholytica, Aeromonas hydrophila and Pseudomonas aeruginosa using the co-culture assays. Amoebal survival rate with different bacterial strains were determined. With the exception of Proteus mirabilis that showed decreased survival rates inside amoebal cells, other bacterial isolates could survive and multiply inside Allovahlkampfia spelaea that was associated with decreased survival rates of the amoeba. Particularly, Pseudomonas aeruginosa, Aeromonas hydrophila and MRSA exhibited significantly increased multiplication rates inside amoeba. Our study demonstrated that Allovahlkampfia spelaea may act as a replicative host for pathogenic bacteria with environmental and clinical implications.

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Section: Co-culture Of a Spelaea And Bacteriasupporting

confidence: 93%

Allovahlkampfia spelaea is a Potential Environmental Host for Pathogenic Bacteria

Mohamed¹,

Huseein²,

Farrag³

et al. 2016

J Bacteriol Parasitol

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“…E. coli K1 strain RS218 (O18 : K1 : H7) is a cerebrospinal fluid isolate from a neonate with meningitis (Silver et al, 1980;Achtman et al, 1983). Several isogenic gene-deletion mutants of K1 were used, including a fimH-deletion mutant (DfimH) (Alsam et al, 2006;Khan et al, 2007), an ompAdeletion mutant (DompA) (Khan et al, 2003) and a cnf1-deletion mutant (Dcnf1) (Khan et al, 2002(Khan et al, , 2003. In addition, a capsuledeletion mutant (DneuDB) derived from K1 was used Jung et al, 2007).…”

Section: Methodsmentioning

confidence: 99%

Development of a novel ex vivo insect model for studying virulence determinants of Escherichia coli K1

Mokri-Moayyed

Goldsworthy

Khan

2008

Journal of Medical Microbiology

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A key step in Escherichia coli K1 meningitis is the crossing of the blood-brain barrier by the bacteria in order to gain entry into the central nervous system (CNS). In this study, a novel ex vivo model to study E. coli K1 invasion of the CNS is described that uses the African migratory locust, Locusta migratoria. By injecting bacteria into isolated locust head capsules, it was demonstrated that E. coli K1 invade the locust brain within 2 h in numbers depending on the concentration of bacteria injected. Using several mutants derived from K1, it was shown that outer-membrane protein A is a critical bacterial determinant required for the E. coli K1 invasion. The isogenic gene-deletion mutants, DfimH, Dcnf1, DneuDB and a rough LPS mutant showed significantly reduced invasion of locust brain. This novel model for the study of E. coli K1 pathogenesis offers several advantages over existing mammalian models in relation to its relative ease of use, cost-effectiveness and ethical acceptability. INTRODUCTIONNeonatal bacterial meningitis caused by Escherichia coli (more than 80 % due to E. coli strains possessing K1 antigen) contributes to more than 50 000 annual deaths worldwide, and it is of serious concern that these numbers remain significant, despite advances in antimicrobial chemotherapy (de Louvois et al., 1991;Unhanand et al., 1993;Kim, 2002Kim, , 2006. Although haematogenous spread is known to be a pre-requisite in E. coli meningitis, it is not clear how circulating bacteria cross the blood-brain barrier to gain entry into the central nervous system (CNS) to produce disease (reviewed by Kim, 2001Kim, , 2002Kim, , 2006. Over the last few decades only a handful of bacterial virulence determinants (such as outer-membrane protein A, FimH, cytotoxic necrotizing factor-1, Ibe proteins, Traj and AslA) have been identified as associated with E. coli K1 pathogenesis (Kim, 2006). The E. coli genome possesses approximately 5.3 Mbp, and approximately 500 kb of the E. coli K1 genome (RS218 strain) is not present in the genome of the E. coli K-12 strain MG1655, so it is reasonable to anticipate the existence of several as yet unknown virulence determinants involved in E. coli meningitis. Current studies have relied upon vertebrate models to study E. coli pathogenesis, but mammalian models are expensive, not routinely available in many laboratories, require labour-intensive management and have ethical implications. There are many parallels between the innate immune responses of mammals and insects, and it is envisaged that insects could make useful models for the study of disease pathogenesis (Scully & Bidochka, 2006), especially as insects possess a highly selective blood-brain barrier exhibiting functional properties comparable with that of vertebrates (Carlson et al., 2000). Here, Locusta migratoria, the African migratory locust, is used as a model to study E. coli pathogenesis.The aim of the present study was to develop an ex vivo locust model specifically to study invasion of the CNS by E. coli. To achieve this, ligated he...

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“…The role of free-living protozoa in the ecology and epidemiology of food-borne pathogens such as Campylobacter, Salmonella, and Escherichia coli has already been documented (31)(32)(33), but for Y. enterocolitica, only brief descriptions of intraprotozoan replication, probably followed by the killing and digestion of the bacterial strain (34), and increased resistance to free chlorine in their early intraprotozoan lifestyle (19) have been reported so far.…”

mentioning

confidence: 99%

Behavior of Yersinia enterocolitica in the Presence of the Bacterivorous Acanthamoeba castellanii

Lambrecht

Baré

Damme

et al. 2013

Appl Environ Microbiol

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c Free-living protozoa play an important role in the ecology and epidemiology of human-pathogenic bacteria. In the present study, the interaction between Yersinia enterocolitica, an important food-borne pathogen, and the free-living amoeba Acanthamoeba castellanii was studied. Several cocultivation assays were set up to assess the resistance of Y. enterocolitica to A. castellanii predation and the impact of environmental factors and bacterial strain-specific characteristics. Results showed that all Y. enterocolitica strains persist in association with A. castellanii for at least 14 days, and associations with A. castellanii enhanced survival of Yersinia under nutrient-rich conditions at 25°C and under nutrient-poor conditions at 37°C. Amoebae cultivated in the supernatant of one Yersinia strain showed temperature-and time-dependent permeabilization. Intraprotozoan survival of Y. enterocolitica depended on nutrient availability and temperature, with up to 2.8 log CFU/ml bacteria displaying intracellular survival at 7°C for at least 4 days in nutrient-rich medium. Transmission electron microscopy was performed to locate the Yersinia cells inside the amoebae. As Yersinia and Acanthamoeba share similar ecological niches, this interaction identifies a role of free-living protozoa in the ecology and epidemiology of Y. enterocolitica.

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Escherichia coli interactions with Acanthamoeba: a symbiosis with environmental and clinical implications

Cited by 92 publications

References 19 publications

Allovahlkampfia spelaea is a Potential Environmental Host for Pathogenic Bacteria

Allovahlkampfia spelaea is a Potential Environmental Host for Pathogenic Bacteria

Development of a novel ex vivo insect model for studying virulence determinants of Escherichia coli K1

Behavior of Yersinia enterocolitica in the Presence of the Bacterivorous Acanthamoeba castellanii

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