The effects of a set of conditions on aminoglycoside uptake were determined. Membrane vesicles either with a membrane potential (A0,) of -125 mV (adequate to drive lysine uptake) or with succinate, lactate, or phenazine methosulfate did not accumulate gentamicin unless components of protein synthesis were included. Ribosomally resistant (rpsL) Escherichia coli cells demonstrated energy-dependent phase II uptake similar to that of a streptomycin-susceptible strain of E. coli when treated with 100 ,ug of puromycin per ml. Puromycin (100 ,ug/ml) also increased the uptake of the cationic compounds polyamine and arginine. These studies support a role of protein synthesis in aminoglycoside uptake and in the development of energy-dependent phase II. A* of cells did not increase either at the initiation of or during energy-denpendent phase II, showing that energydependent phase II is not due to an elevation of A+. In a Bacillus subtilis system, significant streptomycin uptake requires a threshold value of A* which varies depending upon the concentration of streptomycin used. At 25 ,ug/ml, the uptake of streptomycin reached maximal levels after exceeding the threshold value, whereas at 100 p.g/ml there was a gradual increase of the uptake to the maximal after the threshold value was exceeded. Several studies supported the view that electron transport has a specific role other than its requirement to produce the cellular &*. The uptake of gentamicin was stimulated to a greater extent by phenazine methosulfate-ascorbate than by the ionophore nigericin in strains of E. coli, although nigericin stimulated Ai, to a greater degree. Cells with 25% of the normal quinone concentration had values identical to cells with the normal quinone concentration, but the quinone-deficient cells had a significantly lower rate of gentamicin uptake. KCN prevented gentamicin uptake but did not prevent the development of A+. The effects of ubiquinone depletion in an E. coli strain were more evident on gentamicin uptake than on ATP-driven glutamine transport or proton motive force-driven proline transport, consistent with a specific requirement for quinones in aminoglycoside uptake. A detailed explanation of the mechanism of accumulation of streptomycin and gentamicin and a proposed mechanism for killing bacterial cells by these agents have been provided.The uptake of the aminoglycoside antibiotics streptomycin and gentamicin has been shown to be influenced by a complex set of conditions. It has been shown that the kinetics of uptake involve an initial energy-independent phase associated with ionic binding to the cell surface and cytoplasmic membrane. This is followed by two energy-dependent phases, a slow initial rate of uptake termed energy-dependent phase I (EDP-I) and a second accelerated rate termed energy-dependent phase II (EDP-II). Initiation of the latter phase requires binding to ribosomes (reviewed in references 2 and 11).The most effective energy source has been demonstrated to be electron transport involving quinone oxidation-reducti...

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Other components of electron transport and oxidative phosphorylation were normal. These mutants involve ferrocytochrome c551 oxidoreductase formed only on anaerobic growth but illustrate transport defects in aerobically grown cells.The selection of bacterial mutants with increased resistance to aminoglycoside antibiotics, particularly streptomycin and neomycin, has yielded target-and transport-type mutants. Target mutants show a narrow spectrum of resistance. Abnormalities of ribosomal 30S subunit proteins have been characterized for streptomycin and kanamycin resistance, and those of ribosomal ribonucleic acid have been characterized for kasugamycin resistance. A mutant affecting protein L6 of the 50S ribosomal subunit has been detected for gentamicin but only in association with a mutation affecting gentamicin transport

Food safety in Malaysia is not considered an issue yet. From the previous year (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) records, the incidence rate of food poisoning had been fluctuating and despite that, cases continue to occur especially among school students. As a developing nation, it is high-time that Malaysia begins to emphasize on food safety to reduce the burden of foodborne illness in the socio-economic development of the country, and at the same time, gain benefits in terms of economic returns and trade through food safety enforcement. Most importantly, public health is achieved through food safety implementation and accentuation. The current standing point of the Malaysia's food safety is discussed in this review. In addition, the review will also discuss the role of academicians as intervention contributions in tackling food safety issues. The review is hoped to provide valuable and concentrated information and knowledge to readers in the light to drive Malaysia into ensuring safer food for the public.

Shiga-toxin producing Escherichia coli bacteria are well known to be the pathogenic bacteria that cause traveler diarrhea. E. coli O157: H7 from the group of Shiga-toxin producing E. coli cause even severe infection which can lead to fatality for humans. In this study, local beef and Indian buffalo were selected to determine the presence of Shiga-toxin producing E. coli and E. coli O157: H7 using Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. Among 108 samples, eight (7.41%) samples from local beef and Indian buffalo were detected a positive on E. coli O157: H7 while thirteen (12.04%) samples were detected positive for Shiga-toxin producing E. coli gene. Out of 108 samples, eleven isolates of E. coli O157: H7 were successfully isolated in order to carry out the antibiotic susceptibility test. Shiga-toxin producing E. coli isolates were found susceptible to ceftazidime (100%), moxifloxacin (83.33%), sulphamethoxazole (66.67%), ampicillin (50%), amoxycillin (50%), ciprofloxacin (50%), erythromycin (33.33%) and penicillin G (33.33%). E. coli O157: H7 isolates were susceptible toward erythromycin (100%), ceftazidime (100%), ciprofloxacin (100%) and moxifloxacin (100%), sulphamethoxazole (60%), ampicillin (20%), amoxycillin (20%), and penicillin G (0%). The safety of both local beef and Indian buffalo was challenged by the presence of both Shiga-toxin producing E. coli and E. coli O157: H7. Better and safer ways of removing the pathogen from local beef and Indian buffalo should be researched more deeply.