Genetic diversity and risk factors for the transmission of antimicrobial resistance across human, animals and environmental compartments in East Africa: a review.

BACKGROUND The emergence and spread of antimicrobial resistance (AMR) present a challenge to disease control in East Africa. Resistance to beta-lactams, which are by far the most used antibiotics worldwide and include the penicillins, cephalosporins, monobactams and carbapenems, is reducing options for effective control of both Gram-positive and Gram-negative bacteria. The World Health Organization, Food and Agricultural Organization and the World Organization for Animal Health have all advocated surveillance of AMR using an integrated One Health approach. Regional consortia also have strengthened collaboration to address the AMR problem through surveillance, training and research in a holistic and multisectoral approach. This review paper contains collective information on risk factors for transmission, clinical relevance and diversity of resistance genes relating to extended-spectrum beta-lactamase-producing (ESBL) and carbapenemase-producing Enterobacteriaceae, and Methicillin-resistant Staphylococcus aureus (MRSA) across the human, animal and environmental compartments in East Africa. MAIN BODY The review of the AMR literature (years 2001 to 2019) was performed using search engines such as PubMed, Scopus, Science Direct, Google and Web of Science. The search terms included 'antimicrobial resistance and human-animal-environment', 'antimicrobial resistance, risk factors, genetic diversity, and human-animal-environment' combined with respective countries of East Africa. In general, the risk factors identified were associated with the transmission of AMR. The marked genetic diversity due to multiple sequence types among drug-resistant bacteria and their replicon plasmid types sourced from the animal, human and environment were reported. The main ESBL, MRSA and carbapenem related genes/plasmids were the CTX-Ms (45.7%), SCCmec type III (27.3%) and IMP types (23.8%), respectively. CONCLUSION The high diversity of the AMR genes suggests there may be multiple sources of resistance bacteria, or the possible exchange of strains or a flow of genes amongst different strains due to transfer by mobile genetic elements. Therefore, there should be harmonized One Health guidelines for the use of antibiotics, as well as regulations governing their importation and sale. Moreover, the trend of ESBLs, MRSA and carbapenem resistant (CAR) carriage rates is dynamic and are on rise over time period, posing a public health concern in East Africa. Collaborative surveillance of AMR in partnership with regional and external institutions using an integrated One Health approach is required for expert knowledge and technology transfer to facilitate information sharing for informed decision-making

Anatomical and biochemical studies of anthocyanidins in flowers of Anagallis monelli L. (Primulaceae) hybrids

Violet, lilac and red flower colors segregated in an F-3 population obtained from hybridizing blue and orange breeding lines of Anagallis monelli at UNH. One individual per color was studied, as well as true-blue cultivar \u27Skylover Blue\u27. Anatomical examination revealed typical petal layout with upper epidermis, loose mesophyll and lower epidermis. Cells in upper and lower epidermis were categorized by their vacuole color. Blue and red individuals had mostly blue and red cells, respectively. Lilac and violet individuals had blue and bicolored (red and blue) cells on both surfaces, and red cells on the lower epidermis only. Violet individuals had more blue cells on the upper epidermis than lilac individuals. Anthocyanidins were determined by HPLC for each petal epidermis. Blue flowers had only malvidin in both petal surfaces, red flowers had mostly delphinidin with traces of malvidin. Lilac and violet flowers had more malvidin than delphinidin. For violet and lilac flowers respectively, 2 and 3% delphinidin in upper petal surfaces result in a reddish tone while in the lower surface 33 and 25% delphinidin result in a red color. pH in upper and lower petal surfaces were significantly different for each individual, which may affect final flower color. (C) 2007 Elsevier B.V. All rights reserved

From cellular micro-compartmentation to inter-organ communications : the kinetic basis for molecular controls in photoperiodism

An autonomous self-sustained ~24 h oscillation of metabolic activity functions as a physiological clock to allow living systems seasonal adaptation of behaviour, like flowering or hibernation. Until recently circadian rhythms were considered to be a characteristic of eukaryotic cells despite a very early report by Halberg on the observation of a circadian rhythm in E. coli. With the detection of circadian oscillations of metabolic activity in Synechococcus, circadian rhythmicity has proven to exist on all levels of biological organisation from prokaryotic cells to unicellular eukaryotes to higher plants, animals and man. Circadian rhythmicity is an in viva feature of living cells and cannot be observed in vitro. Higher frequency oscillations, however, can be found in many biochemical reactions in vitro as well as in viva. This overview on rhythmic organisation of metabolism in living systems will discuss how macro-parameters like pH, ionic balances (osmos), redox state and phosphorylation potential or hydrophobicity control metabolic functions like photosynthesis, respiration, nitrogen fixation. The temporal control of metabolic pathways involves oscillatory networks in transcription, translation or posttranslational modulation of protein structure and function. Changes in macroparameter status are due to precise feedback networks in basic metabolism leading to a circadian rhythm in overall energy metabolism and thus in metabolic control of timing. Multifactorial changes in environmental conditions like light intensity and -quality, temperature, water status, ionic balances, pressure, etc. are transduced into a network of intracellular signal processing leading to a combinatorial interaction of transcription factors and outputs with cell-, tissue- and organ-specific response-patterns. Compartmentation is coupled to vectorial metabolism and electron transport and the involvement of membrane pores and ion channels. The generation of specific changes in membrane potential can be expected. The physical state of membranes is involved in the transduction of temperature signals and the control of expression of nuclear, mitochondrial and plastid genes which also can be modulated by photoreceptors like the red / far red reversible phytochromes, the blue / UV-A and the UV-B photoreceptors and the feeding of sugars. Membrane-bound processes are controlling and vice versa are controlled by voltage gated ion channels and pores, giving rise to an overall electro-chemical-hydraulic integration of organs and the whole organism on the basis of Mitchell's chemiosmotic theory of energy transduction. The electrophysiological integration offers the possibility for characterisation of cells, organs and organisms by electrophysiogrammes as a means for non-invasive continuous in vivo monitoring of physiology and behaviour

Uptake, translocation and fate of trichloroacetic acid in a Norway spruce/soil system.

Trichloroacetic acid (TCA) is a secondary atmospheric pollutant formed by photooxidation of chlorinated solvents in the troposphere––it has, however, recently been ranked among natural organohalogens. Its herbicidal properties might be one of the factors adversely affecting forest health. TCA accumulates rapidly in conifer needles and influences the detoxification capacity in the trees. The aim of the investigations––a survey of which is briefly given here––was to elucidate the uptake, distribution and fate of TCA in Norway spruce. For this purpose young nursery-grown plants of Norway spruce (Picea abies (L.) Karst.) were exposed to [1,2-14C]TCA and the fate of the compound was followed in needles, wood, roots, soil and air with appropriate radio-indicator methods. As shown by radioactivity monitoring, the uptake of TCA from soil by roots proceeded most rapidly into current needles at the beginning of the TCA treatment and was redistributed at later dates so that TCA content in older needles increased. The only product of TCA metabolism/biodegradation found in the plant/soil-system was CO2 (and corresponding assimilates). TCA biodegradation in soil depends on TCA concentration, soil humidity and other factors

Biodegradation of trichloroacetic acid in Norway spruce/soil system.

Trichloroacetic acid (TCA) belongs to secondary atmospheric pollutants affecting the forest health. Distribution of [1,2-C-14]TCA-residues and TCA biodegradation were investigated in 4-year-old nursery-grown trees of Norway spruce [Picea abies (L.) Karat.] in the whole plant/soil system. Radioactivity was monitored in needles, wood, roots and soil as well as in the air. During two weeks of exposure TCA was continuously degraded, especially in the soil. Estimates of radioactivity balance showed loss of radioactivity into the atmosphere in the form of (CO2)-C-14; unincorporated [1,2-C-14]TCA, chloroform, carbon monoxide and methane were not detected at all. TCA degradation to CO2 was indicated also in the spruce needles. Moreover, it was found that soil litter contained [1,2-C-14]TCA unavailable to microorganisms