Bacteriological, molecular, and pathological studies on the Gram‐positive bacteria Aerococcus viridans and Enterococcus faecalis and their effects on Oreochromis niloticus in Egyptian fish farms

2020 ◽  
Author(s):  
Islam Elgohary ◽  
Alaa Eldin Eissa ◽  
Nasser Gamal Fadel ◽  
Jehan Ibrahim Abd Elatief ◽  
Mahmoud A. Mahmoud
1988 ◽  
Vol 55 (4) ◽  
pp. 597-602 ◽  
Author(s):  
Lydia Bautista ◽  
Rohan G. Kroll

SummaryEffects of the addition of a proteinase (Neutrase 1–5S) and a peptidase (aminopeptidase DP-102) as agents for accelerating the ripening of Cheddar cheese on the survival of some non-starter bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coliand aSalmonellasp.) were studied throughout a 4-month ripening period. The enzymes were found to have no significant effect on the survival of the Gram-positive bacteria but some significant effects were observed, at some stages of the ripening period, with the Gram-negative bacteria in that lower levels were recovered from cheeses treated with the enzyme system.


2003 ◽  
Vol 69 (10) ◽  
pp. 5746-5753 ◽  
Author(s):  
Yukio Yamamoto ◽  
Yoshikazu Togawa ◽  
Makoto Shimosaka ◽  
Mitsuo Okazaki

ABSTRACT Lactic acid bacteria exhibiting activity against the gram-positive bacterium Bacillus subtilis were isolated from rice bran. One of the isolates, identified as Enterococcus faecalis RJ-11, exhibited a wide spectrum of growth inhibition with various gram-positive bacteria. A bacteriocin purified from culture fluid, designated enterocin RJ-11, was heat stable and was not sensitive to acid and alkaline conditions, but it was sensitive to several proteolytic enzymes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that enterocin RJ-11 had a molecular weight of 5,000 in its monomeric form. The amino acid sequence determined for purified enterocin RJ-11 exhibited high levels of similarity to the sequences of enterocins produced by Enterococcus faecium.


2017 ◽  
Author(s):  
Elizabeth V. K. Ledger ◽  
Vera Pader ◽  
Andrew M. Edwards

SummaryDaptomycin is a lipopeptide antibiotic with activity against Gram-positive bacteria. We have shown previously thatStaphylococcus aureuscan survive daptomycin exposure by releasing membrane phospholipids that inactivate the antibiotic. To determine whether other pathogens possess this defence mechanism, phospholipid release and daptomycin activity were measured after incubation ofStaphylococcus epidermidis, Group A or B streptococci,Streptococcus gordoniiorEnterococcus faecaliswith the antibiotic. All bacteria released phospholipid in response to daptomycin, which resulted in at least partial inactivation of the antibiotic. However,E. faecalisshowed the highest levels of lipid release and daptomycin inactivation. As shown previously forS. aureus, phospholipid release byE. faecaliswas inhibited by the lipid biosynthesis inhibitor platensimycin. In conclusion, several pathogenic Gram-positive bacteria, includingE. faecalis, inactivate daptomycin by releasing phospholipids, which may contribute to the failure of daptomycin to resolve infections caused by these pathogens.


2007 ◽  
Vol 2 (12) ◽  
pp. 1934578X0700201 ◽  
Author(s):  
Janne Rojas ◽  
Judith Velasco ◽  
Luis B. Rojas ◽  
Tulia Díaz ◽  
Juan Carmona ◽  
...  

The essential oils from leaves of Baccharis latifolia and B. prunifolia collected in January 2006 were analyzed by GC/MS. The yields of oils extracted by hydrodistillation were 0.27 and 0.29% for B. latifolia and B. prunifolia, respectively. Sixteen (B. latifolia) and twenty nine (B. prunifolia) components were identified by comparison of their mass spectra with the Wiley GC-MS Library data and by their retention indices (RI). The identified products may be divided into four different groups: monoterpenes (9.0% B. latifolia; 43.9% B. prunifolia), oxygenated monoterpenes (0.8% B. latifolia; 5.4% B. prunifolia), sesquiterpenes (20.4% B. latifolia; 45.9% B. prunifolia) and oxygenated sesquiterpenes (69.8% B. latifolia; 1.9% B. prunifolia). The oils showed antibacterial activity only against Gram positive bacteria, with MIC values for Staphylococcus aureus (ATCC 25923) of 80 μg/mL (B. latifolia) and Enterococcus faecalis (ATCC 29212) of 90 μg/mL and 260 μg/mL (B latifolia and B. prunifolia, respectively).


2002 ◽  
Vol 46 (4) ◽  
pp. 1108-1111 ◽  
Author(s):  
Junius Clark ◽  
Joan C. Fung-Tomc ◽  
Beatrice Minassian ◽  
Yuan-Hwang Tsai ◽  
Hyekyung Yang ◽  
...  

ABSTRACT BMS-247243, a novel cephalosporin inhibitory for methicillin-resistant staphylococci, primarily has activity against gram-positive bacteria. The activities of BMS-247243, cefotaxime, and ceftriaxone against streptococci and Streptococcus pneumoniae were similar. BMS-247243 inhibits Enterococcus faecalis but not Enterococcus faecium. BMS-247243 also inhibits many inherently vancomycin-resistant species (Leuconstoc, Lactobacillus, Pediococcus) and anaerobic gram-positive bacteria.


1999 ◽  
Vol 181 (18) ◽  
pp. 5790-5799 ◽  
Author(s):  
Martin H. Lee ◽  
Aphakorn Nittayajarn ◽  
R. Paul Ross ◽  
Cynthia B. Rothschild ◽  
Derek Parsonage ◽  
...  

ABSTRACT We have identified and characterized an Enterococcus faecalis alkaline phosphatase (AP, encoded by phoZ). The predicted gene product shows homology with alkaline phosphatases from a variety of species; it has especially high similarity with two alkaline phosphatases from Bacillus subtilis. Expression ofphoZ in Escherichia coli, E. faecalis, Streptococcus agalactiae (group B streptococcus [GBS]), or Streptococcus pyogenes (group A streptococcus [GAS]) produces a blue-colony phenotype on plates containing a chromogenic substrate, 5-bromo-4-chloro-3-indolylphosphate (XP or BCIP). Two tests were made to determine if the activity of the enzyme is dependent upon the enzyme’s subcellular location. First, elimination of the signal sequence reduced AP activity to 3% of the wild-type activity (or less) in three species of gram-positive bacteria. Restoration of export, using the signal sequence from C5a peptidase, restored AP activity to at least 50% of that of the wild type. Second, we engineered two chimeric proteins in which AP was fused to either a periplasmic domain or a cytoplasmic domain of lactose permease (a membrane protein). In E. coli, the periplasmic fusion had 17-fold-higher AP activity than the cytoplasmic fusion. We concluded that AP activity is export dependent. The signal sequence deletion mutant, phoZΔss, was used to identify random genomic fragments from GBS that encode exported proteins or integral membrane proteins. Included in this set of fragments were genes that exhibited homology with the Rib protein (a cell wall protein from GBS) or with DppB (an integral membrane protein from GAS). AP acts as a reporter enzyme in GBS, GAS, and E. faecalis and is expected to be useful in a variety of gram-positive bacteria.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Duan ◽  
Huikuan Chu ◽  
Katharina Brandl ◽  
Lu Jiang ◽  
Suling Zeng ◽  
...  

AbstractComplement receptor of immunoglobulin superfamily (CRIg) is expressed on liver macrophages and directly binds complement component C3b or Gram-positive bacteria to mediate phagocytosis. CRIg plays important roles in several immune-mediated diseases, but it is not clear how its pathogen recognition and phagocytic functions maintain homeostasis and prevent disease. We previously associated cytolysin-positive Enterococcus faecalis with severity of alcohol-related liver disease. Here, we demonstrate that CRIg is reduced in liver tissues from patients with alcohol-related liver disease. CRIg-deficient mice developed more severe ethanol-induced liver disease than wild-type mice; disease severity was reduced with loss of toll-like receptor 2. CRIg-deficient mice were less efficient than wild-type mice at clearing Gram-positive bacteria such as Enterococcus faecalis that had translocated from gut to liver. Administration of the soluble extracellular domain CRIg–Ig protein protected mice from ethanol-induced steatohepatitis. Our findings indicate that ethanol impairs hepatic clearance of translocated pathobionts, via decreased hepatic CRIg, which facilitates progression of liver disease.


2010 ◽  
Vol 5 (9) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Erich Schmidt ◽  
Stefanie Bail ◽  
Susanne Mirjam Friedl ◽  
Leopold Jirovetz ◽  
Gerhard Buchbauer ◽  
...  

Commercially available aroma samples were evaluated for their olfactory quality by professional perfumers and tested for their antimicrobial activity. Agar diffusion and agar-dilution were used as test methods and a set of two Gram-positive ( Staphylococcus Aureus and Enterococcus faecalis) and four Gram-negative bacterial strains ( Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris G, Klebsiella pneumoniae and Salmonella abony) and a yeast, Candida albicans, were the test microorganisms. All the investigated compounds were active against Gram-positive bacteria, especially β-caryophyllene against Enterococcus faecalis (MIC 6 ppm), but only few substances showed activity towards Gram-negative bacteria, except for cinnamic acid, which was active against all (MIC 60 ppm) and Candida albicans, against which cinnamic acid and caryophyllene oxide showed high activity (MIC < 60 ppm).


2008 ◽  
Vol 3 (3) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Janne Rojas ◽  
Judith Velasco ◽  
Antonio Morales ◽  
Luis Rojasa ◽  
Tulia Díaz ◽  
...  

The essential oil from the leaves of Baccharis trinervis (Lam.) Pers., collected in May 2006, was analyzed by GC/MS. A yield of 0.2% oil was obtained by hydrodistillation. Forty three components were identified by comparison of their mass spectra with those in the Wiley GC-MS Library data base. The major components were germacrene D (20.4%), limonene (15.4%), δ-cadinene (5.2%), β-caryophyllene (4.8%), α-pinene (4.5%) and bicyclogermacrene (4.0%). The essential oil showed antibacterial activity against the important human pathogenic Gram positive bacteria Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212, with MIC values of 80 and 200 μg/mL, respectively.


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