Plasmid biology Chromosome (a)Plasmid replication inde of chromosom (c)Cell-to-cell transfer during conjugation p Somes (a) Integration of plasmid into chromosome
Plasmid Biology Episomes
Plasmid Biology Growth cuning (b) Curing of plasmid
Plasmid Biology
Types of Plasmids and Their Biological significance The presence of plasmids in a cell can have a profound influence on the cells phenotype the ability of conjugation the ability of rhizobium to interact with plants the resistance to antibiotics and heavy metals the degradation of octane, camphor et al the production of enterotoxin the applications in genetic engineering
Types of Plasmids and Their Biological Significance • The presence of plasmids in a cell can have a profound influence on the cell’s phenotype: – the ability of conjugation – the ability of Rhizobium to interact with plants – the resistance to antibiotics and heavy metals – the degradation of octane, camphor et al – the production of enterotoxin – the applications in genetic engineering
Types of Plasmids and Their functions TABLE9.3 Types of plasmids lype Organisms Conjugative plasmids F plasmid, Escherichia coli; Pfdm, K, Pseudomonas: P, Vibrio cholerae: SCP, Streptomyces R Wide variety of antibiotics(ao Section 11.13) Enteric bacteria, Staphylococcus Resistance to mercury, cadmium, nickel, cobalt, zinc, arsenic pseudomonas aO Section 14.18) Bacteriocin and antibiotic production Enteric bacteria; Clostridium; Streptomyces Physiological functions Lactose, sucrose, urea utilization, nitrogen fixation Enteric bacteria Degradation of octane, camphor, naphthalene, salicylate Ps seudomonas Pigment production Erwinia, Staphylococcus Nodulation and symbiotic nitrogen fixation(o Section 14.23 Rhizobium Virulence plasmids Enterotoxin, K antigen, endotoxin(oo Sections 19.8-19.11) Escherichia coli Tumorigenic plasmid (aD Section 14.22) Agrobacterium tumefaciens Adherence to teeth(dextran)(oo Section 19.3 Streptococcus mutans Coagulase, hemolysin, fibrinolysin, enterotoxin(oo Sections 19.7 and 19.9) Staphylococcus aureus "Plasmids have been found in most bacterial genera
Types of Plasmids and Their Functions
Resistance Plasmids(r-plasmids the most well studied plasmids onv The emergence of bacteria resistant to several antibiotics is IS medically Significant Resistance can be transferred via cell-to-cell contact 890 This could be one of the reasons for the rapid rise of multiply 75 resistant strains Plasmid recombination is one cml 725 mean by which multiply resistant organisms might have 50 first arisen Infectious nature of the r plasmids permits rapid spread of the characteristic through populations onT ter Typical example: plasmid R100
Resistance Plasmids (R-Plasmids): the most well studied plasmids • The emergence of bacteria resistant to several antibiotics is medically significant • Resistance can be transferred via cell-to-cell contact • This could be one of the reasons for the rapid rise of multiply resistant strains • Plasmid recombination is one mean by which multiply resistant organisms might have first arisen • Infectious nature of the R plasmids permits rapid spread of the characteristic through populations • Typical example: plasmid R100