Occurrence of MexAB-oprm efflux pump operon on septicemic pseudomonas aeruginosa chromosome

P. aeruginosa remains an important cause of life-threatening bloodstream infection in immunocompromised patients, particularly those with hematologic malignancies complicated by neutropenia. One of the most worrisome characteristics of P. aeruginosa consists is its low antibiotic susceptibility. This low susceptibility is attributable to concerted action of chromosomally-encoded multidrug efflux pumps genes. These genes are often controlled by regulatory gene located on the same operon of efflux pump. One of particular significance is the MexAB-OprM efflux system, which is expressed constitutively, thereby contributing to the well-known intrinsic resistance of this organism to multiple antimicrobials. To detect the occurrence of mexAB-OprM operom on the chromosomes of septicemic P. aeruginosa[SPA]. This study was include 53 Pseudomonas aeruginosa isolates isolated from patients their ages ranging from two days to 73 years,28 males and 25 females. Some of the isolates were isolated from acute, 15[28.3%], and chronic, 7 [13.2%], leukemic patients, 5 [9.4%] from each lymphoma and gastrointestinal neoplasms patients. Nine [17%], 3[5.7%], 6 [11.3%] and 3[5.7%] from urogenital neoplasms, breast cancer patients, septicemic patients due to burn infections and neonatal septicemia respectively. Chromosomal DNA was extracted from SPA isolates and subjected to PCR to amplify three genes of mexAB-OprM efflux pump. Multiplex PCR of mexAB-OprM efflux pump genes revealed that 53 [100%] were positive to all three genes of operon, mexA, mexB and the regulatory gene, mexR. P. aeruginosa can cause septicemia in cancer patients and other compromised patients, like patients suffering from extensive burns and neonatal infants. mexAB-OprM efflux pump genes are a chromosomal encoded genes and can be used as a markers in identification of SPA by molecular methods. These genes can be used individually or collectively in rapid identification of SPA, and rapid detection for mexAB-OprM efflux pump occurrence on their chromosomes

Isolation of tRNA from uropathogenic escherichia coli

Transfer RNA is a type of RNA which during protein synthesis Act as an adaptor molecule, matching amino acids to their codons on mRNA. tRNA also functions in the formation of cross links during peptidoglycan synthesis. The aim of this study is that, extraction of tRNA from uropathogenic Escherichia coli then detect the presence of such molecules after extraction and measure the purity of the tRNA extract solutions. Thirty uropathogenic E.coli isolates were isolated from hospitalized and non hospitalized patients, complaining of urinary tract infections, of Al-Kadhymia Teaching Hospital and subjected to tRNA extraction. A method of tRNA extraction was modified by adding sodium dodecyl sulfate [SDS] instead of urea. Polyacrylamide gel electrophoresis and two methods of staining, ethidium bromide staining and silver staining, as well as spectrophotometric detection were used. Ethidium bromide stained gel reveals bands with molecular weight less than yeast rRNA .Silver stained gel shows bands with molecular weight less than ova albumin[45000 dalton] but with approximate molecular weight of chymotrpsinogen[24000 dalton]. The tRNA extracts were relatively pure with the modified method of extraction. In the present study, a modification of polyacrylamide gel electrophoresis to detect tRNA and to determine their molecular weigh was applied

location of aerobactin determinants of uropathogenic E. coil in association with hemolysin production antibiotic resistance and patient characteristics

Aerobactin, Hemolysin and the resistance to some antibiotics axe important Features of Uropathogenic E. coil [UPEC]. The characteristics of patients from which we isolate the UPEC have associate with these Features and their determinants location. We determined the phenotypic expression and gene location of Aerobactin and phenotypic expression of Hemolysin among 60 UPEC isolates. We correlated the presence of Aerobactin system with antibacterial agents resistance. The expression of Hemolysin and the characteristics of patients. Two methods of plasmid curin, sodium dodecyl sulfate and elevated temperature plasmid curing, are used then plasmid extraction and agarose gel electrophoresis are performed to determine the location of Aerobactin determinants and the size of Aerobactin plasmids, as well as the location of the determinants of some antibiotics resistance which were ampicillin [Am], Tetracycline [Tc], gentamicin [GM], Chloramphenicol [C] and co-trimazole [Co]. Aerobactin and hemolysin expression among UPEC isolates were 93.3% and 35% respectively. The isolates of non compromised patients produce statistically higher rate of expressed hemolysin [90.5% p<0.01]. Plasmid-borne Aerobactin was absent in UPEC isolates of non compromised patients [89.5%, p<0.01]. On the contrary compromised patient isolates express plasmid Aerobactin of 59.5% [p<0.02]. We also found that Aerobactin determinants are located on a plasmid in compromised patient isolates and associated with the absence of chromosomal Hemolysin production [82.9%, p<0.01]. Yet, The chromosomal aerobactin is associated with hemolysin production [61.9%, p<0.02]. Furthermore, UPEC isolates of compromised patients carry relatively large plasmid of Aerobactin [85.7%. p<0.05] and these large plasmids carry either chloramphenicol [83.3%.p<0.02] or gentamicin determinants [100%. P<0.01] but not co-trimazole, tetracycline or ampicillin. The isolates of non compromised patients carry chromosomal Aerobactin and hemolysin. While the isolates of compromised patients express plasmid Aerobactin and do not express chromosomal hemolysin. Aeobactin plasmids are relatively large plasmids and carry either chloramphenicol or gentamicin resistance determinants