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Introduction: New Delhi metallo-β-lactamase (NDM)-producing K. pneumoniae poses a high risk, especially among Egyptian pediatric patients who consume carbapenems antibiotics very widely and without adequate diagnostic sources. In addition, presence of efflux pump genes such as OqxAB increases resistance against many groups of antimicrobials which exacerbates the problem faced for human health. This study aimed to determine NDM variants among K. pneumoniae strains isolated from pediatric patients in Egypt, analyze the presence of OqxAB genes, and molecular characterization of blaNDM-5-positive K. pneumoniae.Methods: Fifty-six K. pneumoniae isolates were recovered from pediatric patients, and tested for carbapenemase by modified carbapenem inactivation methods (mCIM) test. Minimum inhibitory concentrations of meropenem and colistin were determined by meropenem E-test strips and broth microdilution, respectively. PCR was used for the detection of the resistant genes (ESBL gene (blaCTX-M), carbapenemase genes (blaNDM, blaKPC) colistin resistant (mcr1, mcr2)) and genes for efflux pump (oqxA and oqxB). BlaNDM was sequenced. The effect of efflux pump in NDM-5-producing isolates was assessed by measuring MIC of ciprofloxacin and meropenem before and after exposure to the carbonyl cyanide 3-chlorophenylhydrazone (CCCP). The horizontal gene transfer ability of blaNDM-5 was determined using liquid mating assay and PCR-based replicon typing (PBRT) was done to determine the major plasmid incompatibility group.Results: Twenty-nine isolates were positive for blaNDM-1, nine isolates were positive for blaNDM-5, and 15 isolates were positive for blaKPC. There is a significant increase of meropenem MIC of NDM-5-positive isolates compared with NDM-1-positive isolates. In addition, 38 isolates were positive for CTX-M, and 15 isolates were positive for mcr1. Both OqxA and OqxB were detected in 26 isolates and 13 isolates were positive for OqxA while 11 isolates were positive for OqxB only. All NDM-5-producing isolates except one isolate could transfer their plasmids by conjugation to their corresponding transconjugants (E. coli J53). Plasmid replicon typing showed that FII was predominant in NDM-5-producing K. pneumoniae. Similar strains were found between the three isolates and similarity was also detected between the two isolates.Conclusion: The highly resistant K. pneumoniae producing blaNDM-5 type was firstly isolated from pediatric patients. The association of efflux pump genes such as OqxAB is involved in resistance to ciprofloxacin. This highlighted the severity risk of blaNDM-5-positive K. pneumonia as it could transfer blaNDM-5 to other bacteria and has more resistance against carbapenems. This underlines the importance of continuous monitoring of infection control guidelines, and the urgent need for a national antimicrobial stewardship plan in Egyptian hospitals. [ABSTRACT FROM AUTHOR]

Recently, Mobile Ad hoc Networks (MANETs) have witnessed rapid development due to the low cost, diversity, and simplicity of mobile devices. Such devices can form a reliable network in a short time for use as a rescue information system after a natural disaster, where the communication infrastructure may no longer be available or accessible. Because the nodes in such a network are free to move at any time in the absence of centralized control, routing is considered to be the most challenging issue. Moreover, some routing protocols, such as Neighbor Coverage-Based Probabilistic Rebroadcast (NCPR), completely rely on preset variables, which are required to be set by the system administrator based on the scenario. Unfortunately, the setting that is proper for a specific scenario is not suitable for another scenario. In addition, some other routing protocols, such as Ad hoc On-demand Distance Vector (AODV), employ the Route REQuest message (RREQ) flooding scheme to find a path to a particular destination in the route discovery stage. Although the flooding scheme guarantees better reachability, it introduces undesirable routing overhead, which in turn leads to system performance degradation. Thus, this paper proposes a novel routing protocol, neighbor-based Dynamic Connectivity Factor routing Protocol (DCFP), that is able to dynamically probe the status of the underlying network without the intervention of a system administrator based on a novel connectivity metric, while reducing the RREQ overhead using a new connectivity factor. Furthermore, extensive simulation experiments are conducted to evaluate the performance of the proposed DCFP, where the NCPR and AODV are used as a benchmark. The proposed DCFP manages to address the need for preset variables in NCPR. Simulation results show that DCFP outperforms both NCPR and AODV in terms of end-to-end delay, normalized routing overhead, MAC collision, energy consumption, network connectivity, and packet delivery ratio due to its novel mechanism for reducing redundant RREQ.

Providing a seamless handover in the Internet of Thing (IoT) applications with minimal efforts is a big challenge in mobility management protocols. Several research efforts have been attempted to maintain the connectivity of nodes while performing mobility-related signalling, in order to enhance the system performance. However, these studies still fall short at the presence of short-term continuous movements of mobile nodes within the same network, which is a requirement in several applications. In this paper, we propose an efficient group-based handoff scheme for the Mobile Nodes (MNs) in order to reduce the nodes handover during their roaming. This scheme is named Enhanced Cluster Sensor Proxy Mobile IPv6 (E-CSPMIPv6). E-CSPMIPv6 introduces a fast handover scheme by implementing two mechanisms. In the first mechanism, we cluster mobile nodes that are moving as a group in order to register them at a prior time of their actual handoff. In the second mechanism, we manipulate the mobility-related signalling of the MNs triggering their handover signalling simultaneously. The efficiency of the proposed scheme is validated through extensive simulation experiments and numerical analyses in comparison to the state-of-the-art mobility management protocols under different scenarios and operation conditions. The results demonstrate that the E-CSPMIPv6 scheme significantly improves the overall system performance, by reducing handover delay, signalling cost and end-to-end delay.

Broadcasting is an essential and effective mechanism used to disseminate data on several types of networks such as mobile ad hoc network. Such method is adopted by a considerable number of routing protocols, in particular, in the route discovery stage since the broadcasting is easy to implement and certainly provides an ideal connectivity among nodes. However, the broadcasting increases the routing overhead, packet delay, which negativity affects the throughput due to the excessive use of the redundant Route REQuest message. In addition, the network is susceptible to so-called broadcast storm problem. Therefore, developing a new routing protocol, which is able to relieve the unnecessary Route REQuest messages while boosting the performance of the network, is required. In this article, a novel routing protocol for mobile ad hoc network, called scalable neighbor-based mobile routing, is proposed. The broadcasting in this protocol is governed by the inverse relation between the number of neighbors and the probability of the rebroadcasted Route REQuest messages. Extensive simulation experiments are carried out to evaluate the performance of the proposed protocol and to compare the state-of-the-art protocols, namely, neighbor coverage-based probabilistic rebroadcast, with the latest version of ad hoc on-demand distance vector protocol. Simulation results show that scalable neighbor-based mobile routing outperforms both protocols, the neighbor coverage-based probabilistic rebroadcast and the ad hoc on-demand distance vector, in terms of routing overhead, medium access control collision, end-to-end delay, packet delivery ratio, and energy consumption.

Bacterial ghosts (BGS) are empty non-living envelopes produced either genetically or chemically. This study investigated a novel chemical protocol for the production of Neisseria meningitidis ghost vaccine using tween 80 followed by a pH reduction with lactic acid. For our vaccine candidate, both safety and immunogenicity aspects were evaluated. The ghost pellets showed no sign of growth upon cultivation. BGS were visualized by scanning electron microscopy, illustrating the formation of trans-membrane tunnels with maintained cell morphology. Gel electrophoresis showed no distinctive bands of the cytoplasmic proteins and DNA, assuring the formation of ghost cells. In animal model, humoral immune response significantly increased when compared to commercial vaccine (p < 0.01). Moreover, serum bactericidal assay (SBA) recorded 94.67% inhibition compared to 64% only for the commercial vaccine after three vaccination doses. In conclusion, this is the first N. meningitidis ghost vaccine candidate, proven to be effective, economic, and with significant humoral response and efficient SBA values; however, clinical studies should be performed. [ABSTRACT FROM AUTHOR]

Pathogenic bacteria cause disease outbreaks and threaten human health, prompting the research on advanced detection assays. Herein, we developed a selective molecular imprinted aptasensor for sensitive and prompt quantitation of Staphylococcus aureus (S. aureus) bacteria. The aptasensor was constructed by immobilization of aptamer on gold nanoparticles modified magnetic nanoparticles (apt-AuNPs@ Fe3O4). A functional monomer (o-phenylenediamine, o-phen) was electro-polymerized on the surface of the as-synthesized nanocomposite in the presence of a template (S. aureus). After removing S. aureus, the formed imprinted sites were available to extract pathogenic bacteria from complicated matrices. The surface morphology of the as-fabricated nanocomposites was characterized using different spectroscopic and electrochemical methods. Moreover, we thoroughly evaluated factors affecting the synthesis and determination procedures. The molecular imprinted aptasensor exhibited a wide linear range of 101–107 CFU mL−1 with a Limit of Detection, LOD (signal to noise = 3) of 1 CFU mL−1. The aptasensor detected S. aureus in milk, conduit water, and apple juice samples with good recoveries % and satisfactory relative standard deviations (RSDs %) values. [ABSTRACT FROM AUTHOR]

Industrialization processes in Giza governorate (Egypt) brings various organic and inorganic contaminants to surface and ground waters therein. Arable lands located nearby these industrial activities use such waters for irrigation; nevertheless, the contaminants that may exist in irrigation waters adversely affect soil quality and crop yields. Accordingly, periodic monitoring of water quality in this area has become an obligation to ensure its safe use for irrigation. Eighteen irrigation (canals and drain) water samples were collected from different industrial locations nearby the arable lands across Giza governorate in 2019 for quality evaluation. A control (well water) sample was also collected from this governorate so far away from the industrial zone for data comparison. Generally, the studied locations are located within the arid region and maybe the ground waters there are hydraulically connected. The salinity of the collected waters ranged from medium to high according to the classification of FAO. No sodicity, B or Mg hazards were detected in all water samples. On the other hand, the studied water samples were all classified as very hard water since their values of total hardness (TH) ranged from 154.5- 293.5 mg L-1 . Concentrations of Co and Pb in all water samples were below the permissible levels while Cd toxicity was detected in almost all water samples. Ni-hazard was identified in only one location. Besides, soils were sampled from the locations nearby the water resources. The principal component analyses indicate that the abovementioned potentially toxic elements (PTEs) in soil originated from almost one distinct source (weathering of rocks along the river path and not from different industrial origins). Their concentrations were below the permissible levels in all soil locations, in spite of that, almost all soils exhibited low pollution levels with PTEs according to the calculations of pollution load index. Concerning the correlations between the total PTEs contents in soil versus soil characteristics, Cd and Co contents were correlated significantly and positively with the CaCO3 content in soils while Pb was significantly correlated with soil organic matter, and Ni with soil pH. In conclusion, the discharges of the factories in the industrial zone of Giza should be monitored periodically to avoid further negative environmental consequences on the surroundings. Also, there is an intensive need to remediate contaminated wastewater prior to their discharges to the surrounding environment. [ABSTRACT FROM AUTHOR]

Wheat is a strategic crop in Egypt. Its local consumption is increasing continuously accordingly; Egypt has become the largest wheat importer worldwide. The sustainable approach for increasing wheat productivity is probably through organic additives. For this reason, animal, chicken and plant residues were collected from an experimental farm for preparation of (1) plant residue compost (PRC) via composting a mixture of air-dried and chopped rice and soybean straw at a rate of 1:1 and (2) animal residue compost (ARC) via composting a mixture of chicken and cattle manure at a rate of 1:1. The main aim of this study is to compare between the implications of amending a clayey soil with animal versus plant residues for improving soil physical and chemical characteristics. Also, this study considers the changes in soil fertility owing to these additives, hence their outcomes on wheat growth and productivity. To achieve this goal, a field investigation was conducted following a split-split design in which the two types of composts were plotted in main plots while the rates of compost application (15 and 25 Mg per hectare) were plotted in subplots. Non-amended control plots were also included for data comparison. All plots were cultivated with wheat seeds in winter 2018 and received the recommended doses of NPK fertilizers to compare between the two types of composts as conditioners not as fertilizers. The experiment lasted for 160 days until maturity. All composts improved considerably soil physical (soil bulk density, total porosity, saturated hydraulic conductivity and penetration resistance) and chemical (soil organic matter and CEC) characterises, especially with increasing their rate of application. In this concern, the results of the two types of composts were comparable. Also, these additives boosted grain and straw yields, yield components (spike length, spike weight, number of spikelets/spike, 100-grain weight). Moreover, they enriched soils with N, P, K, Fe, Mn, Zn and Cu in available forms; hence raised their contents within wheat shoots and grains, with superiority for ARC versus PRC. There were significant positive correlations between shoot and grain yields in relation to the nutritional status of these plant parts. Accordingly, organic additives, especially animal residues, should be included in the coming sustainable approaches for increasing wheat production. [ABSTRACT FROM AUTHOR]