PA 20, a semi-selective medium for isolation and enumeration of Pantoea ananatis

Goszczynska, Teresa; Venter, Stephanus N.; Coutinho, Teresa A.

doi:10.1016/j.mimet.2005.05.004

Cited by 27 publications

(22 citation statements)

References 10 publications

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“…Pathogenicity of P. ananatis strains was determined on onion leaves as described previously with slight modifications (10). Briefly, a sterile needle was dipped into the bacterial colonies on TSB agar plates grown for 24 h. The needle was then inserted under the epidermis of a leaf.…”

Section: Methodsmentioning

confidence: 99%

The Plant Pathogen Pantoea ananatis Produces N -Acylhomoserine Lactone and Causes Center Rot Disease of Onion by Quorum Sensing

et al. 2007

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A number of gram-negative bacteria have a quorum-sensing system and produce N-acyl-L-homoserine lactone (AHL) that they use them as a quorum-sensing signal molecule. Pantoea ananatis is reported as a common colonist of wheat heads at ripening and causes center rot of onion. In this study, we demonstrated that P. ananatis SK-1 produced two AHLs, N-hexanoyl-L-homoserine lactone (C6-HSL) and N-(3-oxohexanoyl)-Lhomoserine lactone (3-oxo-C6-HSL). We cloned the AHL-synthase gene (eanI) and AHL-receptor gene (eanR) and revealed that the deduced amino acid sequence of EanI/EanR showed high identity to those of EsaI/EsaR from P. stewartii. EanR repressed the ean box sequence and the addition of AHLs resulted in derepression of ean box. Inactivation of the chromosomal eanI gene in SK-1 caused disruption of exopolysaccharide (EPS) biosynthesis, biofilm formation, and infection of onion leaves, which were recovered by adding exogenous 3-oxo-C6-HSL. These results demonstrated that the quorum-sensing system involved the biosynthesis of EPS, biofilm formation, and infection of onion leaves in P. ananatis SK-1.

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Section: Methodsmentioning

confidence: 99%

The Plant Pathogen Pantoea ananatis Produces N -Acylhomoserine Lactone and Causes Center Rot Disease of Onion by Quorum Sensing

et al. 2007

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“…In South Africa the pathogen causes disease on maize, onion and Eucalyptus spp. [2-5] but has also been reported to infect pineapple [6], rice [7], melon [8], sudan grass and sorghum [9,10]. The mechanism of spread of P. ananatis between host plants is largely unknown.…”

Section: Introductionmentioning

confidence: 99%

Comparative genomics of type VI secretion systems in strains of Pantoea ananatisfrom different environments

et al. 2014

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BackgroundThe Type VI secretion system (T6SS) has been identified in several different bacteria, including the plant pathogenPantoea ananatis. Previous in silico analyses described three different T6SS loci present in the pathogenic strain of P. ananatis LMG 20103. This initial investigation has been extended to include an additional seven sequenced strains of P. ananatis together with 39 strains from different ecological niches. Comparative and phylogenetic analyses were used to investigate the distribution, evolution, intra-strain variability and operon structure of the T6SS in the sequenced strains.ResultsThree different T6SS loci were identified in P. ananatis strain LMG 20103 and designated PA T6SS 1-3. PA T6SS-1 was present in all sequenced strains of P. ananatis and in all 39 additional strains examined in this study. In addition, PA T6SS-1 included all 13 core T6SS genes required for synthesis of a functional T6SS. The plasmid-borne PA T6SS-2 also included all 13 core T6SS genes but was restricted to only 33% (15/46) of the strains examined. In addition, PA T6SS-2 was restricted to strains of P. ananatis isolated from symptomatic plant material. This finding raises the possibility of an association between PA T6SS-2 and either pathogenicity or host specificity. The third cluster PA T6SS-3 was present in all strains analyzed in this study but lacked 11 of the 13 core T6SS genes suggesting it may not encoded a functional T6SS. Inter-strain variability was also associated with hcp and vgrG islands, which are associated with the T6SS and encode a variable number of proteins usually of unknown function. These proteins may play a role in the fitness of different strains in a variety of ecological niches or as candidate T6SS effectors. Phylogenetic analysis indicated that PA T6SS-1 and PA T6SS-2 are evolutionarily distinct.ConclusionOur analysis indicates that the three T6SSs of P. ananatis appear to have been independently acquired and may play different roles relating to pathogenicity, host range determination and/or niche adaptation. Future work will be directed toward understanding the roles that these T6SSs play in the biology of P. ananatis.

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“…Inner fleshy scales appearing healthy were removed with forceps to expose symptomatic scales. Approximately 8 mm 3 of tissue from symptomatic scales was then removed and macerated using a sterile scalpel; the macerate dilution-streaked onto nutrient agar (NA) (17) and a semiselective medium for P. ananatis (PA 20) (14), and the plates were incubated in the dark at 28°C for 1 to 3 days. Pure cultures of 18 bacterial strains isolated from onion bulbs grown in New York were stored at -80°C in 1.5-ml sterile tubes containing 1.0 ml of 15% (vol/vol) glycerol in water (Table 1).…”

Section: Methodsmentioning

confidence: 99%

“…There have been numerous reports describing onion leaf symptoms caused by P. ananatis in the field or under greenhouse and laboratory conditions (11,12,19). Furthermore, most published pathogenicity tests for P. ananatis and a closely related bacterium, P. agglomerans, in onion have relied on the development of leaf symptoms (8,10,11,14). Consequently, bulbs were rarely examined for symptoms.…”

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confidence: 99%

Infection of Onion Leaves by Pantoea ananatis Leads to Bulb Infection

et al. 2013

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PA 20, a semi-selective medium for isolation and enumeration of Pantoea ananatis

Cited by 27 publications

References 10 publications

The Plant Pathogen Pantoea ananatis Produces N -Acylhomoserine Lactone and Causes Center Rot Disease of Onion by Quorum Sensing

The Plant Pathogen Pantoea ananatis Produces N -Acylhomoserine Lactone and Causes Center Rot Disease of Onion by Quorum Sensing

Comparative genomics of type VI secretion systems in strains of Pantoea ananatisfrom different environments

Infection of Onion Leaves by Pantoea ananatis Leads to Bulb Infection

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