Antimicrobial resistance patterns and transferable traits in Enterobacteriaceae isolates from poultry in Tlemcen, Algeria

Background: Antibiotics are overused in poultry industry, and this has resulted in the emergence of multidrug resistant (MDR) bacteria. The current study is aimed at determining antimicrobial resistance (AMR) patterns of Enterobacteriaceae isolates from poultry in the west of Algeria.Methodology: Different chicken samples (kidney, bone and intestine) were collected and processed for culture using standard microbiological methods to isolate Enterobacteriaceae. Isolates were identified biochemically using API 20E, while isolated Escherichia coli was typed for O1, O2 and O78 antigens using slide agglutination with specific antisera. All identified isolates were tested against 26 antibiotic disks using the Kirby Bauer disk diffusion method according to the CLSI standards. The minimum inhibitory concentrations (MICs) of chloramphenicol, tetracycline, nalidixic acid, ofloxacin and ciprofloxacin were determined for selected isolates. Conjugative plasmid transfer, plasmid incompatibility and colicin tests were used to detect transferable resistance traits in 48 selected E. coli isolates.Results: One hundred and thirty-eight bacteria species were isolated, which included Escherichia coli (n=107), Salmonella spp (n=11), Klebsiella spp (n=8), Enterobacter spp (n=7), Pseudomonas spp (n=3) and Citrobacter spp (n=2). Serotyping identified 24 agglutinable E. coli isolates with O78:K80 (n=11), O1:K1 (n=9) and O2:K1 (n=4). Antibiotic susceptibility showed high frequency of E. coli resistance to nalidixic acid (89.7%), tetracycline (82.2%), streptomycin (82.2%), nitrofurantoin (68.2%), ampicillin (45.8%), ticarcillin (44.9%), piperacillin(42.1%), and chloramphenicol (15.9%). The percentage of multi-drug resistance isolates (resistance to more than 3 antibiotic classes) was 87.9%. The results of conjugative transfer in 48 E. coli isolates shows that the most important resistance traits transferred by plasmids are ASTeSuTmp (18.5%) and SuTmp (12.3%).Conclusion: This study confirmed the presence of multiple antibiotic resistant E. coli and other members of family Enterobacteriaceae in poultry in Algeria, and showed that these antibiotic resistance traits are easily disseminated by plasmids, with dire consequences on human health. Keywords : Poultry, Enterobacteriaceae, antimicrobial resistance, conjugation, plasmid.   French title:  Profils de résistance aux antimicrobiens et caractères transférables des isolats d'entérobactéries provenant de volailles à Tlemcen, Algérie   Contexte: Les antibiotiques sont surutilisés dans l'industrie de la volaille, ce qui a entraîné l'émergence de bactéries multirésistantes (MDR). L'étude actuelle vise à déterminer les profils de résistance aux antimicrobiens (RAM) des isolats d'Enterobacteriaceae provenant de volailles dans l'ouest de l'Algérie.  Méthodologie: Différents échantillons de poulet (rein, os et intestin) ont été prélevés et traités pour la culture en utilisant des méthodes microbiologiques standard pour isoler les Enterobacteriaceae. Les isolats ont été identifiés biochimiquement en utilisant l'API 20E, tandis que Escherichia coli isolé a été typé pour les antigènes O1, O2 et O78 en utilisant l'agglutination sur lame avec des antisérums spécifiques. Tous les isolats identifiés ont été testés contre 26 disques antibiotiques en utilisant la méthode de diffusion sur disque de Kirby Bauer selon les normes CLSI. Les concentrations minimales inhibitrices (CMI) du chloramphénicol, de la tétracycline,de l'acide nalidixique, de l'ofloxacine et de la ciprofloxacine ont été déterminées pour certains isolats. Des tests de transfert plasmidique conjugatif, d'incompatibilité plasmidique et de colicine ont été utilisés pour détecter des traits de résistance transférables dans 48 isolats sélectionnés d'E. coli.Résultats: Cent trente-huit espèces de bactéries ont été isolées, parmi lesquelles Escherichia coli (n=107), Salmonella spp (n=11), Klebsiella spp (n=8), Enterobacter spp (n=7), Pseudomonas spp (n=3) et Citrobacter spp (n=2). Le sérotypage a identifié 24 isolats d'E. coli agglutinables avec O78: K80 (n=11), O1: K1 (n=9) et O2: K1 (n=4). La sensibilité aux antibiotiques a montré une fréquence élevée de résistance d'E. coli à l'acide nalidixique (89,7%), à la tétracycline (82,2%), à la streptomycine (82,2%), à la nitrofurantoïne (68,2%), àl'ampicilline (45,8%), à la ticarcilline (44,9%), à la pipéracilline (42,1%) et le chloramphénicol (15,9%). Le pourcentage d'isolats de résistance multi-médicaments (résistance à plus de 3 classes d'antibiotiques) était de 87,9%. Les résultats du transfert conjugatif dans 48 isolats d'E. coli montrent que les traits de résistance les plus importants transférés par les plasmides sont ASTeSuTmp (18,5%) et SuTmp (12,3%).Conclusion: Cette étude a confirmé la présence de multiples E. coli résistants aux antibiotiques et d'autres membres de la famille des Enterobacteriaceae chez les volailles en Algérie et a montré que ces traits de résistance aux antibiotiques sont facilement disséminés par les plasmides, avec des conséquences désastreuses sur la santé humaine. Mots clés: volaille, entérobactéries, résistance aux antimicrobiens, conjugaison, plasmide

Klebsiella pneumoniae producing extended spectrum β-lactamase in Regional Military University Hospital of Oran, Algeria: antibiotic resistance, biofilm formation, and detection of blaCTX-M and blaTEM genes

Background: Klebsiella pneumoniae is a bacterial pathogen commonly associated with severe nosocomial and community acquired infections  especially through the acquisition of extended spectrum β-lactamases (ESβL) and biofilm formation capacity. The objectives of this study are to determine the prevalence of K. pneumoniae ESβL (KP-ESβL)-producing isolates in the Regional Military University Hospital of Oran (HMRUO) Algeria,characterize their antibiotic resistance profile, genetically detect blaTEM and blaCTX-M genes, and evaluate their biofilm formation capacity.Methodology: Different clinical specimens including blood, cerebrospinal fluids, urine and catheter, pus, perirectal abscess, and surgical wounds were collected from patients with suspected clinical infections in different units and departments of the hospital. The specimens were cultured on Blood, MacConkey and CLED agar (for urine only) plates and incubated aerobically for 24 hours at 37°C for preliminary identification of bacteria using conventional colony morphology, Gram stain reaction, and disk diffusion test for antibiotic susceptibility testing (AST). Confirmation of isolates, antibiogram, minimum inhibitory concentration (MIC) and detection of resistance phenotypes, were carried out by the automated Vitek 2 (BioMérieux) identification and susceptibility method. ESβL production was confirmed by the synergy and combination disk tests. ESβL genes were detected by conventional simplex PCR and biofilm formation was detected by the tissue culture plate (TCP) method.Results: A total of 630 patients’ clinical samples (one sample per patient) were processed. Klebsiella pneumoniae was isolated in 40 (6.3%) samples, and 15 of these (37.5%) produced ESβL. In the disk diffusion AST assay, all 40 K. pneumoniae isolates were resistant to ampicillin and ticarcillin while all 40 isolates were sensitive to cefoxitin, imipenem and ertapenem. KP-ESβL producing isolates were more frequently recovered from intensive care unit (33.3%) and from urine (46.7%) samples. Group 1 blaCTX-M genes were detected in 13 of the 15 (86.7%) KP-ESβL isolates, and 46.7% of these isolates were moderate biofilm producers.Conclusion: There is need for health departments to put in place preventative measures through regular surveillance of these resistant pathogens and initiating appropriate infection prevention and control strategies to limit their spread in Algerian hospitals and worldwide. Keywords: Klebsiella pneumoniae, ESβL, biofilm, PCR, antibacterial resistance   French title: Klebsiella pneumoniae productrice de-lactamase spectre tendu dans l'hôpital universitaire militaire régional d'Oran, Algérie: résistance aux antibiotiques, formation de biofilm et détection desgènes blaCTX-M et blaTEM Contexte: Klebsiella pneumoniae est un pathogène bactérien communément associé aux infectionsnosocomiales et communautaires sévères, en particulier par l'acquisition de β-lactamases à spectre étendu(ESβL) et la capacité de formation de biofilm. Les objectifs de cette étude sont de déterminer la prévalence desisolats de K. pneumoniae producteurs de βLSE (KP-βLSE) au CHU d'Oran (HMRUO) Algérie, caractériser leurprofil de résistance aux antibiotiques, détecter génétiquement les gènes blaTEM et blaCTX-M, et évaluer leurcapacité de formation de biofilm.Méthodologie: Différents échantillons cliniques, y compris du sang, des liquides céphalo-rachidiens, de l'urinemictionnelle et du cathéter, du pus, des abcès périrectal et des plaies chirurgicales ont été prélevés despatients suspectés d'infections cliniques dans différentes unités et départements de l'hôpital. Les échantillonsont été cultivés sur des milieu de culture: deglose au sang, MacConkey et CLED (pour l'urine uniquement) etincubés en aérobie pendant 24heures à 37°C pour l'identification préliminaire des bactéries en utilisant lamorphologie conventionnelle des colonies, la coloration de Gram et le test de diffusion sur disque pour les testsde sensibilité aux antibiotiques (AST). La confirmation des isolats, l'antibiogramme, la concentration minimaleinhibitrice (CMI) et la détection des phénotypes de résistance ont été réalisés par la méthode automatiséed'identification et de sensibilité sur Vitek 2 (BioMérieux). La production de βLSE a été confirmée par les tests desynergie et de double disques. Les gènes de βLSE ont été détectés par PCR simplex conventionnelle et laformation de biofilm a été détectée par la méthode de la plaque de culture tissulaire (TCP).Résultats: Un total de 630 échantillons cliniques de patients (un échantillon par patient) ont été traités.Klebsiella pneumoniae a été isolé dans 40 échantillons (6,3%) et 15 d'entre eux (37,5%) ont produit des βLSE.Dans le test AST à diffusion sur disque, tous les 40 isolats de K. pneumoniae étaient résistants à l'ampicilline età la ticarcilline, tandis que les 40 isolats étaient sensibles à la céfoxitine, à l'imipénème et à l'ertapénème. Lesisolats producteurs de KP-βLSE ont été plus fréquemment récupérés dans les unités de soins intensifs (33,3%)et dans les échantillons d'urine (46,7%). Les gènes blaCTX-M du groupe 1 ont été détectés dans 13 des 15 isolatsde KP-βLSE (86,7%), et 46,7% de ces isolats étaient des producteurs de biofilm modérés.Conclusion: Il est nécessaire que les services de santé mettent en place des mesures préventives grâce à unesurveillance régulière de ces pathogènes résistants et à la mise en place de stratégies appropriées deprévention et de contrôle des infections pour limiter leur propagation dans les hôpitaux algériens et dans lemonde. Mots clés: Klebsiella pneumoniae, βLSE, biofilm, PCR, résistance antibactérienne &nbsp

FETI DDM methodologies for the simulation of high gain Ka-band Transmit arrays (single and dual band)

This paper is presenting Finite Element Tearing and Interconnecting (FETI) simulation results of large scale single and dual Ka-band lens transmit-arrays obtained on massively parallel clusters. The computation times observed with the FETI method allow us to consider using it in the optimization phase of such transmit-arrays.info:eu-repo/semantics/publishedVersio

A review of knowledge on the mechanisms of action of the rare sugar D‐tagatose against phytopathogenic oomycetes

d-tagatose is a rare monosaccharide, naturally present at low concentrations in some fruits and dairy products. d-tagatose is "generally recognized as safe" and is used as a low-calorie sweetener in the food industry. It is able to inhibit the growth of numerous microorganisms, such as phytopathogenic oomycetes responsible for important crop diseases. Thanks to the negligible effects on human health and the environment, d-tagatose has been proposed as a sustainable product for crop protection. This review describes the current knowledge on modes of action of d-tagatose against phytopathogenic oomycetes and its potential uses in agriculture. d-tagatose can negatively affect the growth of phytopathogenic oomycetes by inhibiting key enzymes of sugar metabolism, such as β-glucosidase in Phytophthora infestans, and fructokinase and phosphomannose isomerase in Hyaloperonospora arabidopsidis. Moreover, d-tagatose affects sugar content, causes severe mitochondrial alterations, and inhibits respiration processes with the accumulation of reactive oxygen species in P. infestans, but not in P. cinnamomi. Differential effects of d-tagatose are associated with a global gene downregulation in P. infestans and with an efficient transcriptional reprogramming of multiple metabolic processes in P. cinnamomi. d-tagatose displays possible species-specific effects in Phytophthora spp. and nutritional properties on some plant-associated microorganisms. However, inhibitory effects are reversible and P. infestans growth can be restored in the absence of d-tagatose. Further functional studies are discussed in this review, in order to promote the use of d-tagatose for sustainable crop protectio

Trustworthy Federated Learning: A Survey

Federated Learning (FL) has emerged as a significant advancement in the field of Artificial Intelligence (AI), enabling collaborative model training across distributed devices while maintaining data privacy. As the importance of FL increases, addressing trustworthiness issues in its various aspects becomes crucial. In this survey, we provide an extensive overview of the current state of Trustworthy FL, exploring existing solutions and well-defined pillars relevant to Trustworthy . Despite the growth in literature on trustworthy centralized Machine Learning (ML)/Deep Learning (DL), further efforts are necessary to identify trustworthiness pillars and evaluation metrics specific to FL models, as well as to develop solutions for computing trustworthiness levels. We propose a taxonomy that encompasses three main pillars: Interpretability, Fairness, and Security & Privacy. Each pillar represents a dimension of trust, further broken down into different notions. Our survey covers trustworthiness challenges at every level in FL settings. We present a comprehensive architecture of Trustworthy FL, addressing the fundamental principles underlying the concept, and offer an in-depth analysis of trust assessment mechanisms. In conclusion, we identify key research challenges related to every aspect of Trustworthy FL and suggest future research directions. This comprehensive survey serves as a valuable resource for researchers and practitioners working on the development and implementation of Trustworthy FL systems, contributing to a more secure and reliable AI landscape.Comment: 45 Pages, 8 Figures, 9 Table

Neotectonics of the South Marmara Sub-Region

Neotektonik dönemde Kuzey Anadolu Fayı ve kolları, inceleme alanı ve Marmara Bölgesi’nde en etkin tektonik yapıyı oluşturmaktadırlar. KAF, Marmara Bölgesi’nde kuzey ve güney olmak üzere iki kola ayrılır. Bunlardan Marmara Denizi’nin kuzeyinden geçen kol kuzey kol, güneyinden ve inceleme alanından geçen kol ise güney koldur. İnceleme alanında kuzeyde Edincik, Kapıdağı, Bandırma-Mudanya yükselimleri, güneyde Uludağ yükselimi ve Söğütalan platosu yer alır. Bu iki yükselim alanının ortasında doğu-batı uzanımlı bir çöküntü (depresyon) alanı gelişmiştir. Bu yükselim alanları ve çöküntü alanı, neotektonik dönemde Kuzey Anadolu Fayı’nın güney kolunun etkinliği ve kontrolü ile meydana gelmişlerdir. Çöküntü alanı içerisinde ise bir çok çek-ayır biçiminde havzalar oluşmuştur. Bölgede KAF’ın güney koluna ait faylar Yenice-Gönen, Manyas-Mustafakemalpaşa, Uluabat ve Bursa faylarıdır. Sismolojik veriler bölgedeki depremlerin  büyük ölçüde KAF’a ait güney kol üzerinde meydana geldiğini, hasar yapıcı ve yıkıcı depremlerin  hem doğrultu atımlı hem de eğim atımlı faylar üzerinde oluştuğunu göstermektedir.Anahtar Kelimeler: Güney Marmara Bölgesi, Kuzey Anadolu Fayı, çek-ayır havza, yanal atımlı fay.  In neotectonic period, North Anatolian Fault and its branches are the most active in the study area and Marmara Region. NAF is divided into two bracnhes as north and south  in the Marmara Region. The northern branch is located in the north of the Sea of Marmara. The southern branch is located in study area and south of the Sea of Marmara. The South Marmara Region has ptwo uplift areas located at southern and northern margins and a depression between these uplifts. The north uplifts are Edincik, Kapıdağı and Bandırma-Mudanya, south uplifts are Uludağ uplift and Söğütalan Plateau. The uplift and depression areas are contrelled by the southern branch of the NAF in the neotectonic period. In the depression area a lot of pull-apart style basins happened. The southern branch of the North Anatolian Fault, which consists of the Yenice-Gönen, Manyas-M.Kemalpaşa, Uluabat and Bursa faults. According to seismological data of  South Marmara Region, earthquakes have occured on the southern branch of the NAF and earthquakes show that the faults have not only strike-slip but also normal fault characteristics.Keywords: South Marmara Region, North Anatolian Fault, pull-apart basin, strike-slip faul

Seismic tomography of the North Anatolian Fault: New insights into structural heterogeneity along a continental strike-slip fault

Knowledge of the structure of continental strike-slip faults within the lithosphere is essential to understand where the deformation occurs and how strain localizes with depth. With the aim to improve the constraints on the lower crust and upper mantle structure of a major continental strike-slip fault, we present a high-resolution teleseismic tomography of the North Anatolian Fault Zone (NAFZ) in Turkey. Our results highlight the presence of a relatively high velocity body between the two branches of the fault and significant along-strike variations in the NAFZ velocity structure over distances of ~20 km. We interpret these findings as evidence of laterally variable strain focussing caused by preexisting heterogeneity. Low velocities observed in the crust and upper mantle beneath the NAFZ support the presence of a narrow shear zone widening in the upper mantle, where we constrain its width to be ~50 km.Major funding was provided by the UK Natural Environment Research Council (NERC) under grant NE/I028017/1. Equipment was provided and supported by the NERC Geophysical Equipment Facility (SEIS-UK). This project is also supported by Bogaziçi University Scientific ˘ Research Projects (BAP) under grant 6922 and Turkish State Planning Organization (DPT) under the TAM project, number 2007K120610

An example of secondary fault activity along the North Anatolian Fault on the NE Marmara Sea Shelf, NW Turkey

Seismic data on the NE Marmara Sea Shelf indicate that a NNE-SSW-oriented buried basin and ridge system exist on the sub-marine extension of the Paleozoic Rocks delimited by the northern segment of the North Anatolian Fault (NS-NAF), while seismic and multi-beam bathymetric data imply that four NW-SE-oriented strike-slip faults also exist on the shelf area. Seismic data indicate that NW-SE-oriented strike-slip faults are the youngest structures that dissect the basin-ridge system. One of the NW-SE-oriented faults (F1) is aligned with a rupture of the North Anatolian Fault (NAF) cutting the northern slope of the Cinarcik Basin. This observation indicates that these faults have similar characteristics with the NS-NAF along the Marmara Sea. Therefore, they may have a secondary relation to the NAF since the principle deformation zone of the NAF follows the Marmara Trough in that region. The seismic energy recorded on these secondary faults is much less than that on the NAF in the Marmara Sea. These faults may, however, produce a large earthquake in the long term