Molecular Analysis of fimA Operon Genes among UPEC Local Isolates in Baghdad City

Abstract

Specialized Escherichia coli (E. coli) isolates, called uropathogenic E. coli (UPEC), cause most of urinary tract infections (UITs). Once bacteria reached the urinary tract of the host, they have to adhere to the host cell for the colonization. For this purpose, bacteria have different structures including fimbrial adhesins. Most of the UPECs contain type 1 fimbriae encoded by fim operon (fimB, E, A, I, C, D, F, G, H) which is responsible for the adhesive ability in these isolates. Ninety-four isolates of UPEC were obtained from UTI patients in Baghdad hospitals and their diagnosis were confirmed by the PCR method using 16srDNA as a housekeeping gene. The UPEC isolates were tested for their ability of adherence to the urothelial cells obtained from the mid-stream urine from healthy women. Fifty isolates were subjected to detect type1 fimbriae genes (fimA operon) using specific primers followed by sequencing the amplified fragment which they were analyzed by Geneious software. The results confirm that all the isolates were E. coli according to the genetic analysis by the PCR test, and also, the ability of attachment for all isolates were approved (100%). For type 1 fimbriae, the findings figured out that 100% of the isolates harbored fimA,fimI, fimC, fimD, fimG and fimH genes; while 96% of them were positive for fimB, fimF,and 82% of the isolates were positive for fimE. This result exhibited a higher prevalence of fim genes, as the attachment ability was 100%. Approximately, all UPEC have type 1fimbrial genes, so it could be used as a genetic marker in the investigation of E. coli adhesion ability.

Keywords: Uropathogenic Escherichia coli; attachment ability; fimA operon.

Figure 1

A: Genotypic identification for UPEC isolates, B: Pairwise identity and the DNA sequencing for 16s rRNA gene matched with the standard strain E.

Figure 2

A: Gel electrophoresis of DNA segment of the fimB and the standard strain (MK301554) B: Pairwise identity and nucleotide sequence for fimB as compared with the standard NCBI E. coli strain MK301554

Figure 3

A: Amplified PCR amplicon of fimE gene with molecular size reached 550 bp, B: Pairwise identity and nucleotide sequence for fimE as compared with the standard NCBI E. coli strain AP022362.

Figure 4

A: Amplified PCR amplicon of fimA gene with molecular size reached 446 bp, B: Pairwise identity and nucleotide sequence for fimA as compared with the standard NCBI E. coli strain LR883000.

Figure 5

A: Amplified PCR amplicon of fimI gene with molecular size reached 251 bp, B: Pairwise identity and nucleotide sequence for fimI as compared with the standard NCBI E. coli strain CP057888.

Figure 6

A: Amplified PCR amplicon of fimC gene with molecular size reached 477 bp, B: Pairwise identity and nucleotide sequence for fimC as compared with the standard NCBI E. coli strain CP054371.

Figure 7

A: Amplified PCR amplicon of fimD gene with molecular size reached 595 bp, B: Pairwise identity and nucleotide sequence for fimD as compared with the standard NCBI E. coli strain CP034595.

Figure 8

A: Amplified PCR amplicon of fimF gene with molecular size reached 261 bp, B: Pairwise identity and nucleotide sequence fimF as compared with the standard NCBI E. coli strain CP018252.

Figure 9

A: amplified PCR amplicon of fimG gene with molecular size reached 348 bp, B: Pairwise identity for fimG as compared with standard NCBI E. coli strain CP061337.

Figure 10

A: amplified PCR amplicon of fimH gene with molecular size reached 204 bp, B: Pairwise identity for fimH as compared with standard NCBI E. coli strain LR134208.