Bacteriophage resistance alters antibiotic mediated intestinal expansion of enterococci

2019 ◽  
Author(s):  
Yasmin Lau
Genetics ◽  
1984 ◽  
Vol 108 (3) ◽  
pp. 523-532
Author(s):  
Bert Ely ◽  
Ronda H Croft ◽  
Connie J Gerardot

ABSTRACT Mutations in more than 30 genes affect motility in Caulobacter crescentus. We have determined the chromosomal map locations for 27 genes involved in flagellar morphogenesis (fla), three genes involved in flagellar function (mot), and three genes that have a pleiotropic effect on both motility and bacteriophage resistance (ple). Three multigene clusters have been detected at widely separated chromosomal locations, but in addition, there are 12 fla and mot genes that are found at eight additional sites scattered around the C. cresentus chromosome. Thus, there is more scatter of genes involved in flagellar structure and function than has been observed in other bacterial systems.


2001 ◽  
Vol 67 (2) ◽  
pp. 929-937 ◽  
Author(s):  
David O' Sullivan ◽  
R. Paul Ross ◽  
Denis P. Twomey ◽  
Gerald F. Fitzgerald ◽  
Colin Hill ◽  
...  

ABSTRACT The bacteriophage resistance plasmid pAH90 (26,490 bp) is a natural cointegrate plasmid formed via homologous recombination between the type I restriction-modification specificity determinants (hsdS) of two smaller lactococcal plasmids, pAH33 (6,159 bp) and pAH82 (20,331 bp), giving rise to a bacteriophage-insensitive mutant following phage challenge (D. O'Sullivan, D. P. Twomey, A. Coffey, C. Hill, G. F. Fitzgerald, and R. P. Ross, Mol. Microbiol. 36:866–876; 2000). In this communication we provide evidence that the recombination event is favored by phage infection. The entire nucleotide sequence of plasmid pAH90 was determined and found to contain 24 open reading frames (ORFs) responsible for phenotypes which include restriction-modification, phage adsorption inhibition, plasmid replication, cadmium resistance, cobalt transport, and conjugative mobilization. The cadmium resistance property, encoded by the cadA gene, which has an associated regulatory gene (cadC), is of particular interest, as it facilitated the selection of pAH90 in other phage-sensitive lactococci after electroporation. In addition, we report the identification of a group II self-splicing intron bounded by two exons which have the capacity to encode a relaxase implicated in conjugation in gram-positive bacteria. The functionality of this intron was evident by demonstrating splicing in vivo. Given that pAH90 encodes potent phage defense systems which act at different stages in the phage lytic cycle, the linkage of these with a food-grade selectable marker on a replicon that can be mobilized among lactococci has significant potential for natural strain improvement for industrial dairy fermentations which are susceptible to phage inhibition.


1995 ◽  
Vol 4 (3) ◽  
pp. 297-314 ◽  
Author(s):  
Polly K. Dinsmore ◽  
Todd R. Klaenhammer

2006 ◽  
Vol 188 (18) ◽  
pp. 6629-6639 ◽  
Author(s):  
Jonathan O'Driscoll ◽  
Frances Glynn ◽  
Gerald F. Fitzgerald ◽  
Douwe van Sinderen

ABSTRACT The conjugative lactococcal plasmid pNP40, identified in Lactococcus lactis subsp. diacetylactis DRC3, possesses a potent complement of bacteriophage resistance systems, which has stimulated its application as a fitness-improving, food-grade genetic element for industrial starter cultures. The complete sequence of this plasmid allowed the mapping of previously known functions including replication, conjugation, bacteriocin resistance, heavy metal tolerance, and bacteriophage resistance. In addition, functions for cold shock adaptation and DNA damage repair were identified, further confirming pNP40's contribution to environmental stress protection. A plasmid cointegration event appears to have been part of the evolution of pNP40, resulting in a “stockpiling” of bacteriophage resistance systems.


PLoS Genetics ◽  
2015 ◽  
Vol 11 (11) ◽  
pp. e1005667 ◽  
Author(s):  
Ignacio Cota ◽  
María Antonia Sánchez-Romero ◽  
Sara B. Hernández ◽  
M. Graciela Pucciarelli ◽  
Francisco García-del Portillo ◽  
...  

2003 ◽  
Vol 185 (15) ◽  
pp. 4558-4563 ◽  
Author(s):  
Paul Sumby ◽  
Margaret C. M. Smith

ABSTRACT The phase-variable phage growth limitation (Pgl) system of Streptomyces coelicolor A3(2) is an unusual bacteriophage resistance mechanism that confers protection against the temperate phage φC31 and homoimmune relatives. Pgl is subject to phase variation, and data presented here show that this is at least partially due to expansion and contraction of a polyguanine tract present within the putative adenine-specific DNA methyltransferase gene, pglX. Furthermore, the pglX paralogue SC6G9.02, here renamed pglS, was shown to be able to interfere with the Pgl phenotype, suggesting that PglS could provide an alternative activity to that conferred by PglX.


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