Cloning and nucleotide sequence of a flagellin encoding genetic locus from Xenorhabdus nematophilus: phase variation leads to differential transcription of two flagellar genes (fliCD)

ABSTRACT lisRK encodes a two-component regulatory system in the food pathogen Listeria monocytogenes LO28. Following identification of the operon in an acid-tolerant Tn917mutant, a deletion in the histidine kinase component was shown to result in a growth phase variation in acid tolerance, an ability to grow in high ethanol concentrations, and a significant reduction in virulence.

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DNA sequence adjacent to flagellar genes and evolution of flagellar-phase variation.

Journal of Bacteriology ◽

10.1128/jb.155.1.74-81.1983 ◽

1983 ◽

Vol 155 (1) ◽

pp. 74-81 ◽

Cited By ~ 29

Author(s):

E Szekely ◽

M Simon

Keyword(s):

Dna Sequence ◽

Phase Variation ◽

Flagellar Genes

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Development of a pcr system for the characterisation of Salmonella flagellin genes

Acta Veterinaria Hungarica ◽

10.1556/avet.53.2005.2.2 ◽

2005 ◽

Vol 53 (2) ◽

pp. 163-172 ◽

Cited By ~ 8

Author(s):

A. Imre ◽

F. Olasz ◽

B. Nagy

Keyword(s):

Phase Variation ◽

Pcr Primers ◽

The Other ◽

Pcr Analysis ◽

Structural Genes ◽

Flagellin Gene ◽

Specific Pcr ◽

Other Hand ◽

Genetic Interventions ◽

Flagellar Genes

Analysis of flagellin genes was carried out on strains of Salmonella Typhimurium, Salmonella Hadar, Salmonella Abortusequi, Salmonella Enteritidis and Salmonella Gallinarum serovars, using a PCR system designed in this study. The purpose of these studies was to explore the flagellin genes of biphasic and monophasic Salmonellae for future targeted genetic interventions. The PCR primers were designed for two different structural genes of flagellin (fliC, fljB), for the repressor of fliC (fljA), for the operator region of fliC, and for the invertase system responsible for phase variation in Salmonella (hin, hixL, hixR). PCR analysis revealed that all of the examined genes (fliC, fliC-operator, fljB, fljA, hin, hixL, hixR) were present in all S. Typhimurium (n = 10)and S. Hadar (n = 10) strains tested. The results obtained on S. Typhimurium and S. Hadar strains confirmed their biphasic character at DNA level. However, the S. Enteritidis (n = 46) and S. Gallinarum (n = 5) strains lacked the invertase system (hin, hixL, hixR) as well as the fljA and fljB genes, while fliC and its operator were detectable. Consequently, the S. Enteritidis strains could only express fliC gene resulting in phase H1 flagellin. The examined S. Gallinarum strains were also demonstrated to have a cryptic flagellin gene (fliC). On the other hand, PCR results on S. Abortusequi (n = 2) indicated that both flagellin genes (fliC, fljB) and the whole phase variation system were present in both strains tested but only the H2 phase gene (fljB) was expressed. The phenotype of these strains could be clarified by motility test and/or by classical flagellar serology. The findings are also substantiated by the results of serovar-specific PCR for S. Typhimurium and S. Enteritidis. In conclusion, the PCR system developed in this study proved to be suitable for characterisation of Salmonella flagellin genes and confirmed serological results regarding all S. Typhimurium, S. Hadar and S. Enteritidis strains. This system could also identify cryptic flagellar genes of S. Abortusequi and S. Gallinarum.

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Development of a multi-locus typing scheme for anEnterobacteriaceaelinear plasmid that mediates inter-species transfer of flagella

10.1101/664508 ◽

2019 ◽

Author(s):

James Robertson ◽

Janet Lin ◽

Amie Wren-Hedegus ◽

Gitanjali Arya ◽

Catherine Carrillo ◽

...

Keyword(s):

Sequence Data ◽

Phase Variation ◽

Public Health Importance ◽

The Public ◽

Mlst Scheme ◽

Population Structure Analysis ◽

Phenotypic Novelty ◽

Sequence Types ◽

Core Genes ◽

Flagellar Genes

AbstractDue to the public health importance of flagellar genes for typing, it is important to understand mechanisms that could alter their expression or presence. Phenotypic novelty in flagellar genes arise predominately through accumulation of mutations but horizontal transfer is known to occur. A linear plasmid termed pBSSB1 previously identified inSalmonellaTyphi, was found to encode a flagellar operon that can mediate phase variation, which results in the rare z66 flagella phenotype. The identification and tracking of homologs of pBSSB1 is limited because it falls outside the normal replicon typing schemes for plasmids. Here we report the generation of nine new pBSSB1-family sequences using Illumina and Nanopore sequence data. Homologs of pBSSB1 were identified in 154 genomes representing 25 distinct serotypes from 67,758Salmonellapublic genomes. Pangenome analysis of pBSSB1-family contigs was performed using Roary and we identified three core genes amenable to a minimal MLST scheme. Population structure analysis based on the newly developed MLST scheme identified three major lineages representing 35 sequence types, and the distribution of these sequence types was found to span multiple serovars across the globe. This MLST scheme has shown utility in tracking and subtyping pBSSB1-family plasmids and it has been incorporated into the plasmid MLST database under the name “pBSSB1-family”.

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Swarming and Swimming Changes Concomitant with Phase Variation in Xenorhabdus nematophilus.

Applied and Environmental Microbiology ◽

10.1128/aem.61.4.1408-1413.1995 ◽

1995 ◽

Vol 61 (4) ◽

pp. 1408-1413 ◽

Cited By ~ 35

Author(s):

A Givaudan ◽

S Baghdiguian ◽

A Lanois ◽

N Boemare

Keyword(s):

Phase Variation ◽

Xenorhabdus Nematophilus

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Phase Variation in Xenorhabdus nematophilus and Photorhabdus luminescens: Differences in Respiratory Activity and Membrane Energization

Applied and Environmental Microbiology ◽

10.1128/aem.60.1.120-125.1994 ◽

1994 ◽

Vol 60 (1) ◽

pp. 120-125 ◽

Cited By ~ 45

Author(s):

Adam J. Smigielski ◽

Raymond J. Akhurst ◽

Noël E. Boemare

Keyword(s):

Respiratory Activity ◽

Phase Variation ◽

Photorhabdus Luminescens ◽

Xenorhabdus Nematophilus ◽

Membrane Energization

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Heterogeneity in Tandem Octanucleotides within Haemophilus influenzae Lipopolysaccharide Biosynthetic Gene losA Affects Serum Resistance

Infection and Immunity ◽

10.1128/iai.01540-05 ◽

2006 ◽

Vol 74 (6) ◽

pp. 3408-3414 ◽

Cited By ~ 20

Author(s):

Alice L. Erwin ◽

Paul J. Bonthuis ◽

Jennifer L. Geelhood ◽

Kevin L. Nelson ◽

Kirk W. McCrea ◽

...

Keyword(s):

Haemophilus Influenzae ◽

Genetic Locus ◽

Phase Variation ◽

Surface Proteins ◽

Serum Resistance ◽

Biosynthetic Gene ◽

Repeat Region ◽

Repeat Units ◽

Selection For ◽

Simple Sequence

ABSTRACT Haemophilus influenzae is subject to phase variation mediated by changes in the length of simple sequence repeat regions within several genes, most of which encode either surface proteins or enzymes involved in the synthesis of lipopolysaccharides (LPS). The translational repeat regions that have been described thus far all consist of tandemly repeated tetranucleotides. We describe an octanucleotide repeat region within a putative LPS biosynthetic gene, losA. Approximately 20 percent of nontypeable H. influenzae strains contain copies of losA and losB in a genetic locus flanked by infA and ksgA. Of 30 strains containing losA at this site, 24 contained 2 tandem copies of the octanucleotide CGAGCATA, allowing full-length translation of losA (on), and 6 strains contained 3, 4, 6, or 10 tandem copies (losA off). For a serum-sensitive strain, R3063, with losA off (10 repeat units), selection for serum-resistant variants yielded a heterogeneous population in which colonies with increased serum resistance had losA on (2, 8, or 11 repeat units), and colonies with unchanged sensitivity to serum had 10 repeats. Inactivation of losA in strains R3063 and R2846 (strain 12) by insertion of the cat gene decreased the serum resistance of these strains compared to losA-on variants and altered the electrophoretic mobility of LPS. We conclude that expression of losA, a gene that contributes to LPS structure and affects serum resistance, is determined by octanucleotide repeat variation.

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Phase Variation in Xenorhabdus nematophilus

Applied and Environmental Microbiology ◽

10.1128/aem.64.4.1188-1193.1998 ◽

1998 ◽

Vol 64 (4) ◽

pp. 1188-1193 ◽

Cited By ~ 50

Author(s):

Antonia Volgyi ◽

Andras Fodor ◽

Attila Szentirmai ◽

Steven Forst

Keyword(s):

Stationary Phase ◽

Phase I ◽

Phase Ii ◽

Phase Variation ◽

Symbiotic Bacterium ◽

Phenotypic Traits ◽

Variant Form ◽

Cell Type ◽

Variant Cell ◽

Xenorhabdus Nematophilus

ABSTRACT Xenorhabdus nematophilus is a symbiotic bacterium that inhabits the intestine of entomopathogenic nematodes. The bacterium-nematode symbiotic pair is pathogenic for larval-stage insects. The phase I cell type is the form of the bacterium normally associated with the nematode. A variant cell type, referred to as phase II, can form spontaneously under stationary-phase conditions. Phase II cells do not elaborate products normally associated with the phase I cell type. To better define phase variation in X. nematophilus, several strains (19061, AN6, F1, N2-4) of this bacterium were analyzed for new phenotypic traits. An analysis of pathogenicity in Manduca sexta larvae revealed that the phase II form of AN6 (AN6/II) was significantly less virulent than the phase I form (AN6/I). The variant form of N2-4 was also avirulent. On the other hand, F1/II and 19061/II were as virulent as the respective phase I cells. Strain 19061/II was found to be motile, and AN6/II regained motility when the bacteria were grown in low-osmolarity medium. In contrast, F1/II remained nonmotile. The phase II cells did not produce the outer membrane protein, OpnB, that is normally induced during the stationary phase. Both phase I and phase II cells were able to support nematode growth and development. These findings indicate that while certain phenotypic traits are common to all phase II cells, other characteristics, such as virulence and motility, are variable and can be influenced by environmental conditions.

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