ABSTRACT
Due to the implication of docosahexaenoic acid (DHA) in neurogenesis, synaptogenesis, neurite outgrowth and to its high incorporation into the brain, this n-3 long chain polyunsaturated fatty acid (LCPUFA) is considered as crucial in the development and maintenance of the learning memory performance throughout life. In the present chapter we aimed at reviewing data investigating the relation between DHA and cognition during the perinatal period, young adult- and adulthood and neurodegenerative diseases such as Alzheimer disease (AD). In Humans, dietary DHA supplementation from the perinatal period to adulthood does not reveal a clear and consistent memory improvement whereas it is the case in animal studies. The positive effects observed in animal models may have been enhanced by using n-3 PUFA deficient animal models as controls. In animal models of AD, a general consensus on the beneficial effects of n-3 LCPUFA in attenuating cognitive impairment was established. These studies make DHA a potential suitable micronutrient for the maintenance of cognitive performance at all periods of life.
Subject(s)
Cognition/drug effects , Dietary Supplements , Docosahexaenoic Acids/administration & dosage , Adult , Alzheimer Disease/metabolism , Alzheimer Disease/physiopathology , Animals , Brain/drug effects , Brain/physiology , Child , Cognition/physiology , Female , Fetus , Humans , Infant , Learning/drug effects , Learning/physiology , Male , Memory/drug effects , Memory/physiology , PregnancyABSTRACT
We report here the clinical case of an Afro-Caribbean patient referred for complete atrioventricular block for whom a diagnosis of hereditary cardiac amyloidosis was eventually confirmed. Hereditary cardiac amyloidosis is an emerging threat in the Caribbean, and the main goal of this report is to raise the awareness of the disease among physicians.
Subject(s)
Aneurysm, False/therapy , Angiography , Cholecystitis/complications , Cystic Duct/blood supply , Embolization, Therapeutic/methods , Emergencies , Gallbladder/blood supply , Image Enhancement , Tomography, X-Ray Computed , Aged , Aneurysm, False/diagnosis , Cholecystitis/diagnosis , Follow-Up Studies , Humans , MaleABSTRACT
Background: Flies and cockroaches are two insects in close contact with human beings. They are carriers of human pathogenic bacteria on the external areas of their bodies or in their digestive tracts. This study examines Periplaneta americana and Musca domestica collected from the residential areas of six districts in Tangier; Morocco. Methodology: In total; 251 bacteria were isolated from external areas of the participants' bodies and the antimicrobial susceptibility was calculated. Results: The predominant bacterial species included Escherichia coli (17.9); Klebsiella spp. (14.7); Providencia spp. (9.6); Staphylococcus spp. (15.1) and Enterococcus spp. (11.6). The study showed no difference between the species of bacterial strains from American cockroaches and houseflies. Carbapenems and aminoglycosides were active against 100of the Gram-negative bacilli isolated in this study. Staphylococcus spp. strains were susceptible to linezolid; vancomycin; daptomycin; levofloxacin and cotrimoxazole; and no antibiotic resistance was found in Enterococcus spp. Conclusions: In our setting; although both cockroaches and flies collected from residential areas may be vectors of human pathogenic bacteria; the infections caused by them are easily treatable as a result of the high susceptibility of their bacteria to antibiotics routinely used in the community or in hospitals
Subject(s)
Houseflies , Periplaneta , Sprains and StrainsABSTRACT
Background: To investigate the incidence and antibiotic resistance of staphylococcal strains isolated from milk and milk products and to trace the ecological origin of the Staphylococcus aureus isolated. Methodology: Eighty-one samples of raw milk; lben (whey) and jben (cheese) were analyzed for the presence of staphylococcal strains. Isolates were identified by Gram stains; tests for coagulase; the API staph system and the WalkAwayr 40/96; which also determines the antimicrobial susceptibility profiles. The S. aureus strains were biotyped; and variable regions of the coagulase gene were amplified using the polymerase chain reaction. Results: The identification results showed a predominance of coagulase-negative staphylococci (54). Coagulase-positive staphylococci that were identified were divided into 3 groups comprising S. aureus (40); Staphylococcus intermedius (2) and Staphylococcus hyicus (4). Among the S. aureus that was isolated; biotype C was the predominant biotype. Among 40 coagulase gene PCR-amplification products; 37 produced a single band; while 3 isolates produced two bands. The antimicrobial susceptibility-profile of the staphylococcal strains revealed a high incidence of S. aureus to penicillin G. In addition; Staphylococcus lentus presented considerable resistance to the oxacillin; erythromycin and lincomycin. Conclusions: The presence of staphylococci in raw milk; lben and jben in areas of northern Morocco poses a health hazard; so it is necessary for the public health inspectors to properly examine the conditions during production; storage and commercialization of all products made with unpasteurized milk. Key Words: milk products; Staphylococcus; coagulase-gene typing; biotyping; antimicrobial susceptibility
Subject(s)
Coagulase , Cultured Milk Products , StaphylococcusABSTRACT
Antagonism between Bacillus licheniformis M-4 and the pathogenic amoeba Naegleria fowleri HB-1 during cocultivation was influenced by the composition of the medium and the initial amoeba/bacterium ratio. While a ratio of 50 caused complete lysis of amoebae in soil extract with 0.3% glucose (SEG) before 72 h, this ratio had to be at least 12-fold lower in order to obtain similar results in Cline medium. Sporulation of B. licheniformis M-4 took place much earlier in SEG. Amoebicin production was stimulated by the presence of amoebae by either shortening the time of production (as in SEG) or increasing the amount of amoebicins released (as in Cline medium). Electron microscopy showed that amoebae cocultivated in the Cline medium contained bacteria enclosed in digestive vacuoles, while amoebae from SEG cocultures did not.
Subject(s)
Amebicides/metabolism , Bacillus/metabolism , Naegleria fowleri/microbiology , Animals , Bacillus/growth & development , Bacillus/ultrastructure , Microscopy, Electron , Naegleria fowleri/growth & development , Naegleria fowleri/ultrastructureABSTRACT
Amoebicin m4-A from Bacillus licheniformis M-4 exerts a bactericidal and bacteriolytic action on Bacillus megaterium GR10. Protein, DNA, and RNA synthesis are inhibited, and the membrane electrical potential of this bacterium is depleted by amoebicin. Synthesis of DNA and RNA by Naegleria fowleri HB-1 is also inhibited. Liposomes constructed from L-alpha-phosphatidylcholine become permeable to ions, low-molecular-weight solutes, and high-molecular-weight polymers after treatment with amoebicin.
Subject(s)
Amebicides/pharmacology , Anti-Bacterial Agents/pharmacology , Bacillus megaterium/drug effects , Bacillus/metabolism , Naegleria fowleri/drug effects , Peptides , Animals , Liposomes/metabolism , Membrane Potentials/drug effectsABSTRACT
The strain Bacillus licheniformis M-4 produces a 3.4 kDa hydrophilic peptide with antifungal activity, named fungicin M4. Analysis of the purified peptide shows that it contains the amino acids Glu (8), Arg (5), Pro (4), Tyr (8), Val (3), Met (2) and Orn (4). Its inhibitory spectrum is restricted to Microsporum canis CECT 2797, Mucor mucedo CECT 2653, Mucor plumbeus CCM 443, Sporothrix schenckii CECT 2799, Bacillus megaterium and Corynebacterium glutamicum CECT 78. Fungicin M4 exerts biocidal activity on liquid cultures of Sporothrix schenckii CECT 2799.
Subject(s)
Anti-Bacterial Agents/isolation & purification , Antifungal Agents/isolation & purification , Bacillus/chemistry , Peptides , Amino Acids/analysis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Microbial Sensitivity TestsABSTRACT
The strain Bacillus licheniformis D-13 produces three hydrophobic peptides (amoebicins d13-A, d13-B, and d13-C) that elicit antiamoebic activity against human-pathogenic and nonpathogenic species of Naegleria and have a broad spectrum of antibacterial activity. The three amoebicins have the same amino acid composition (three Asp, two Glu, two Val, and nine Leu residues) and molecular weight (1,870). Amoebicin d13-B causes lysis of amoebae through disorganization of the cell membrane. It also induces permeability to 86Rb and membrane disruption in asolectin vesicles.
Subject(s)
Amebicides/pharmacology , Bacillus/metabolism , Bacterial Proteins/pharmacology , Naegleria fowleri/drug effects , Amebicides/chemistry , Amebicides/isolation & purification , Animals , Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purificationABSTRACT
Three antibiotic peptides with amoebolytic activity have been purified from culture supernatants of Bacillus licheniformis M-4 (amoebicins m4-A, m4-B, and m4-C). They were hydrophilic peptides consisting of six different amino acids (Asp, Glu, Ser, Thr, Pro, Tyr). Their molecular weights ranged from 3,000 to 3,200. Purified amoebicins were active against human pathogenic and non-pathogenic strains of Naegleria. They also showed a broad antifungal spectrum, but a narrow antibacterial activity.
Subject(s)
Amebicides/isolation & purification , Bacillus/metabolism , Peptides/isolation & purification , Amebicides/chemistry , Amebicides/metabolism , Amebicides/pharmacology , Animals , Naegleria/drug effects , Naegleria/growth & development , Peptides/chemistry , Peptides/metabolism , Peptides/pharmacologyABSTRACT
An antifungal substance named peptide A12-C has been purified to homogeneity from supernatants of sporulated cultures of Bacillus licheniformis A12. It consists of a 0.77-kDa hydrophilic peptide containing two residues of Glu and one of Arg, Ala, Pro, Tyr and Orn. No fatty acids, phosphorus or carbohydrates have been detected. Peptide A12-C is active on several fungi (Microsporum canis CECT 2797, Mucor mucedo CECT 2653, M. plumbeus (CCM F 443, Sporothrix schenckii CECT 2799 and Trichophyton mentagrophytes CECT 2793) and bacteria (Bacillus megaterium, Corynebacterium glutamicum, Sarcina and Mycobacterium), although the latter are less sensitive.
Subject(s)
Anti-Bacterial Agents/isolation & purification , Antifungal Agents/isolation & purification , Bacillus/chemistry , Peptides/isolation & purification , Amino Acids/analysis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Bacteria/drug effects , Biotechnology , Fungi/drug effects , Peptides/chemistry , Peptides/pharmacologyABSTRACT
Bacillus licheniformis A12 produces two amoebolytic substances (amoebicins A12-A and A12-B) in liquid media during sporulation. Both substances have been purified and characterized. They are heat- and protease-resistant peptides containing aspartic acid, glutamic acid, serine, proline, and tyrosine in a molar ratio of 5:2:2:2:2. No fatty acids or carbohydrates have been detected. Their molecular weight is 1,430. Purified amoebicins A12-A and A12-B exhibit amoebolytic action against Naegleria fowleri. They also exhibit antibiotic action against yeasts (Saccharomyces heterogenicus and Cryptococcus neoformans) and several fungal species (Aspergillus niger, Microsporum canis, Mucor plumbeus, and Trychophyton mentagrophytes). Their antibacterial spectrum appears to be restricted to Bacillus megaterium, Corynebacterium glutamicum, and Sarcina sp.
