The objective of this study was to investigate the prophylactic roles of human enteric derived Lactobacillus plantarum L1 (Ll) and Lactobacillus paracasei L2 (L2), on EHEC O157:H7 infection in rodent models (In vivo). The Lactobacillus suspensions (L1 and L2) were individually and orally administered to experimental rats at a daily two consecutives of 100 μl (108 CFU/ ml/rat) for up to two weeks. Thereafter, on the 8th day of experiment rats were orally challenged with one dose infection of EHEC (105 CFU/ml/rat). Animals mortality and illness symptoms have been monitored. There was no fatal EHEC infection in rats that had been pre‑colonized with the Lactobacillus strains, while most of EHEC infected rats were died (90%). The Stx1 and Stx2 levels were significantly lower (14 and 12 folds) in the L1and L2 pre-inoculated rates respectively, compared with those in the EHEC colonized group. Histological sections were proven the prophylactic roles of L1 and L2, whereas, no effective histological upsets were detected in Lactobacillus + EHEC- colonized rats. The cytopathic symptoms were predominant in kidney and intestinal sections of EHEC infected rats. The kidney sections cytopathy manifested to lining membrane ulceration, infiltration of mononuclear cells and glomerular and tubular epithelium necrosis. The striking attaching and effacing (A/E) lesions were prominent in intestinal sections of EHEC infected animal models.
Inhibitory effect of Lactobacillus plantarum was studied against Escherichia coli O157:H7 in minced beef , as well as the effect of some Spices ( Garlic , Cloves and Black Pepper ) was studied against this bacteria . Plate count method was used to estimate the viable cells of E. coli O157:H7 in the treated meat samples for incubation periods( 0 , 24 and 48) h. Results showed that Lactobacillus plantarum had inhibitory effect against E. coli O157:H7 , when reducing the number of cells after 24, 48 h., and reached to Zero after (24) h. As well as Spices in this study had inhibitory activity against E. coli O157:H7 .Garlic had
... Show MoreBackground: In recent years, the multidrug-resistant (MDR) Escherichia coli has increased in urinary tract infections (UTIs). One of the highly distributed chromosomally encoded traits of resistance is efflux pump. The current study aimed to investigate the most common members of 5 classes of efflux pumps among uropathogenic E. coil isolates.
Methodology: E. coli isolates were isolated using conventional bacteriology tests and confirmed by the uidA gene. An antibiotic susceptibility test has been done against 25 antibiotics using disc diffusion method. Efflux pump genes have been examined via polymerase chain reaction. Biofilm formation was investigated by a
... Show MoreInterferon’s plays a role in innate immune responses through upregulation of costimulatory molecules and induction of proinflammatory cytokines. Interferon alpha (IFN α) type of Interferons. The present study characterized IFNα cDNA . The interferon’s play a great role in protection from infections, caused by microorganisms, and have powerful antiproliferative and immunomodulation activity. In this study DNA was isolated from bovine blood leukocyte, which was used in the quality of matrix for amplification of α-interferon gene with the use of PCR, and isolation of gene α-interferon and transformation in vector pUC18 and expression vector pET24b (+). All plasmids contained an additional DNA fragment size corresponding to the gene
... Show MoreThis study proposed to synthesize iron oxide by biological method nanoparticles. The E.coli is used to reduce Ferric chloride salt into iron particles. The formation of iron oxide nanoparticle was initially monitored by visual observation and then characterized with the help of various characterization techniques such as Uv-vis spectroscopy, (AFM) and (FTIR) analysis, which revealed that the biosynthesized iron oxide nanoparticles were spherical within size 27.7 nm. Optimization of iron oxide nanoparticle biosynthesis by E.coli was performed for parameters (temperature and pH) and the results revealed that temperature 37°C and pH 5 were the optimum conditions for iron oxide nanoparticales biosynthesis by E.coli.<
... Show MoreSome Factors determining the virulence of Escherichia coli ( E. coli ) isolates were studied ,of 25 isolates , 17(group A) uropathogenic E. coli ,6 (group B) infected gastrointestinal tract , 2 (group C) infected wound , beside these group we use the standard strain E. coli HB101 as control group. The twenty five isolates were tested for adherence capability to human buccal cavity epithelial cells by in vitro experiment . The results showed that all isolates have different adhesion capability with mean ranging from (14.35±11.39) to (33.80 ± 22.68) bacteria / epithelial cell It was noticed that isolates EU9, ES6, EW17 displayed high adhesive capability with mean value (33.80 ± 22.68), (32.60 ± 21.19), (29.90±22.50) bacteria /epithelial
... Show MoreThe present study included a collecting of 165 specimens form different sources,
93 isolates were identified as Escherichia coli depending on morphological and
biochemical tests in addition to automated systems such as VITEK 2 and api 20E.
All isolates under study developed high resistance toward cefotaxime, ceftazidime,
ceftriaxone, and ciprofloxacin estimated by minimum inhibitory concentration. Stool
and wound specimens characterized by harbouring the highest resistant isolates in a
percentage reached 100% against antibiotics under study. Insignificant differences
were found between isolates collected from males and females. Upon using disk
displacement method to detect extended spectrum beta lactamases (ESBL),
The effect of crude colicin extracted from E. coli isolated from
urinary tract infection patients on phagocytosis in vitro was studied . Results showed that the effect of crude colicin on phagocytic cells and their activities were concentration dependent. Low concentration (50
Mg/ml) have no significant effect (p>O.OS) on shape, size, migration and engulfment activity of phagocytic cells, while (50, 100 Mg/ml)
enhanced killing activity and increase superoxide ( 02 ) production as indicated by (NBT) test. But high concentration (500 mg/ml) of crude colicin caused inhibition of phagocytic cel
... Show MoreBiofilm formation represents one of the biggest problems facing scientists because of this phenomenon linkage with virulence of bacteria and other clinical environmental problems. In the present study, two clinical isolates,
Escherichia coli, and Staphylococcus aureus were exposed to the non thermal plasma for different intervals of time (1, 2, 4, 8, and 16 min). The biofilm was measured post exposing. It was found that 2 min. exposing to non-thermal plasma reduced the biofilm formation by both clinical isolates significantly. It can be concluded that the ability of S. aureus to form biofilm higher than E. coli and exposing for 2 min to non-thermal plasma sufficient to reduce the biofilm formati
ABSTRACT The role of specific amino acids namely cysteine, methionine, threonine and asparagine in the protection provided by vamin solution against B-lactam inhibition to E. coli was evaluated in vitro. In minimal medium, Cells were treated with 32 ug/ml of penicillin G, carbencillin, hostacillin, cloxacillin and cephalotin in the presence of specific amino acid supplementations. Deletion of specific amino acids from the media abolished the protection provided by vamin. Threonine was essential for the protection of cells against all tested antibiotics, while cysteine was essential for protection against carbencillin and cephalotin Deletion of methionine or asparagine abolished the protec- tion against carbencillin and to a less extent ce
... Show MoreEscherichia coli infections are becoming difficult treated because of extensive resistance to antibiotic among these organisms and manufacturing extended-spectrum beta lactamases enzymes (ESBLs) make them resistant to beta-lactam antibiotics. This study aims to offer a summary of the main horizontal transmission apparatuses between E. coli as well as Staphylococcus aureus and emergence resistance to antibiotics. Fifty of the E. coli and 50 of S. aureus isolates were examined to obtain minimum inhibitory concentration (MIC) results. These isolates were then tested by conventional polymerase chain-reaction for the existence or absenc
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