The well-defined group is L. acidophilus dividing into phylogenetic subgroups of Lactobacillus. Its meaning, although moderately constructed by DNA-DNA homology, contains 32 to 50% of constituents existing in genomic species (GC) (Felis & Dellaglio., 2007). Between ephemeral and permanent residents of normal intestinal flora, Lactobacillus acts as a reservoir of antibiotic resistance genes and provides a model locus for parallel gene transfer (Devirgiliis et al., 2011). E. coli has the ability to colonize different anatomical sites in part through plasticity and genome transformation by gaining or losing genetic material from which it has obtained resistance or virulence influences. Horizontal transfer therefore remains an important factor in the adaptation and evolution of E. coli towards different niches (Ahmed et al., 2008; Mellata et al., 2010). Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay UPEC strains can trigger acute infections and recurrent infections that do not respond to common antimicrobial treatments. ß[n1][n2]-lactam antibiotics, fluoroquinolones or trimethoprim/sulfamethoxazole are generally included in the treatment of urinary tract infections (Chulain et al., 2005; Johnson et al., 2004; Molina-López et al., 2011). According to Johnson (2000), treatment depends on the patient's age, gender, involvement of the pathogen, course of the disease and anatomical areas of the urinary tract. The influence of resistance can be associated with variations in the bacterial genome by acquisition or mutation or by horizontal transmission of extra-chromosomal or chromosomal material (Moura et al., 2009; Backer et al., 2008; Hong et al. al., 2009). Randomly, antibiotic resistance occurs in connection with certain mutations. They represent the importance of defects during DNA duplication or disorganization of DNA deficiency repair mechanisms in bacterial cell division and are recognized as natural mutations. This results in few changes at seven positions of the gyrA gene and three positions of the parC gene. The quinolone-resistant phenotype of Escherichia coli is the result. Antibiotic resistance mechanisms involving efflux or import systems are genetically determined by mutations in gene regulatory regions and even promoter regions known as multidrug resistance (MDR) efflux pumps ( Piddock., 2006; Some changes occur in cells that do not divide or have a low division rate and are related to non-lethal selection pressure that favors bacterial cells. Such mutations are called adaptive and represent the main source of emergence of antibiotic-resistant phenotypes under natural conditions. The error-prone DNA polymerase V (umuCD) and DNA polymerase IV (dinB) that transiently increase the mutation rate are the main points of these processes. By increasing the rate of occurrence of antibiotic-resistant phenotypes of Escherichia coli, certain antibiotics are capable of producing bacterial DNA damage and triggering the SOS mutagenic response. Accumulation of single-stranded DNA due to damage that blocks bacterial chromosome replication leads to the formation of RecA nucleoprotein complexes. A step required for mutagen-dependent assembly of UmuD'2C DNA polymerase V is another role of the RecA coprotease which is to process UmuD into UmuD'. This allowed DNA replication.