4,623 research outputs found
Performance analysis of anaplasma antibody competitive ELISA using the ROC curve for screening of anaplasmosis in camel populations in Egypt
Anaplasmosis is a tick-born and potential zoonotic disease caused by Anaplasma (A.) phagocytophilum, A. ovis, A. platys and A. capra. Anaplasma marginale affecting bovines and camels causing significant economic losses. Camels as an integral part of the socio-economic lifestyle of nomads in semi-arid to arid ecosystems are prone to suffer from subclinical Anaplasma infections. This study aimed to determine the performance and adaptation of commercial competitive Anaplasma ELISA (cELISA) as a tool for screening the seroprevalence of anaplasmosis whitin the camel populations in Egypt. This study was based on the serological investigation of 437 camel sera collected between 2015 and 2016 during a Q fever prevalence study in Egypt using commercially available cELISA for the detection of antibodies specific for Anaplasma in bovine serum. The receiver operating characteristic (ROC) curve, an analysis method for optimizing cutoff values in cELISAs, was used to estimate the sensitivity and specificity using 76 true as serological positive (n = 7) and negative (n = 60) for Anaplasma antibodies. ROC curve analysis was done for 7 true positive and 60 true negative bovine samples and 7 true positive and 29 true negative camel samples serum. Real time PCR and/or conventional PCR was applied to confirm Anaplasma spp. specific-DNA in camel serum as an indication of a true positive and true negative for ROC analysis. Chi square analysis was performed to estimate the association between risk factors and anaplasmosis in camels. The cutoff value was determined as 0.42 (p value ≤ 0.001). Data simulation with randomly generated values revealed a cutoff value of 0.417 (p ≤ 0.001) with resulting 58.1% Se and 97.8% Sp. Seven true positive and 29 true negative camel serum samples was confirmed by PCR. Using the estimated cut off, the seroprevalence in the Nile Valley and Delta and the Eastern Desert domain was 47.4% and 46.4%, respectively. The potential risk factors as domains and origin of animals were less significantly associated with the prevalence of anaplasmosis (domains: χ(2) = 41.8, p value ≤ 0.001 and origin: χ(2) = 42.56, p value ≤ 0.001). Raising awareness especially for veterinarians and animal owners will significantly contribute to the best understanding of anaplasmosis in camels in Egypt. Alternative (in silico) validation techniques and preliminary prevalence studies are mandatory towards the control of neglected anaplasmosis in the camel population
Seroprevalence and Molecular Detection of Bovine Anaplasmosis in Egypt
Bovine anaplasmosis is a tick-borne disease with zoonotic potential, caused by the obligate intracellular bacterium Anaplasma marginale. The disease is distributed worldwide in tropical and subtropical regions. The economic losses from anaplasmosis in animals is of significant importance because it causes severe morbidity and mortality in cattle. Recovered animals may become persistent carriers. Epidemiological information on the actual status of bovine anaplasmosis in Egypt is scarce. Thus, this study aimed to determine anti-Anaplasma antibody and DNA in serum samples using ELISA and PCR, respectively. In total, 758 bovine sera were collected from cattle farms located in 24 Egyptian governorates in 2015 to 2016. Sera were analyzed with the commercially available ‘Anaplasma antibody competitive ELISA v2’ kit and ‘AmpliTest Anaplasma/Ehrlichia spp. real time TaqMan TM PCR. Anaplasma spp. antibodies were detected in 140 (18.5%) (CI: 15.8–21.4%) of the investigated sera by ELISA, and Anaplasma/Ehrlichia-DNA was detected in 40 (5.3%) (CI: 3.8–7.1%) of the positive sera by real time PCR. Co-detection of both Anaplasma spp. and Coxiella burnetii-specific antibodies was proven in 30 (4%) of the investigated sera. The results of this work confirm the significant prevalence of bovine anaplasmosis in Egypt. Raising awareness in decision makers of the public health, veterinarians and animal owners is required to reduce the spread of infection
Sprayer for Quantitative Application of Odor Stimuli
A novel device is described for the quantitative application of chemical stimuli. The device uses ultrasound to disperse a solution of volatile chemicals as an aerosol. A motor-driven syringe controls the rate at which the solution is released from a glass capillary. Vibration of the capillary disperses the released solution into microdroplets that evaporate completely within a few centimeters of the tip. The ratio of chemical stimulus to solvent is maintained until the liquid is dispersed and therefore the release rate of the chemical stimulus can be set and calculated straightforwardly from the dilution factor and the dynamically controllable speed of the syringe plunger. The sprayer permits the delivery of chemical stimulus independent of relative vapor pressures of the components and of environmental factors such as temperature. The sprayer is easy to operate, can be constructed from inexpensive materials, and can be used to emit odor stimuli in the wind tunnel or any other bioassay for pheromones and plant volatile
Supersymmetric mode converters
Originally developed in the context of quantum field theory, the concept of
supersymmetry (SUSY) can be used to systematically design a new class of
optical structures. In this work, we demonstrate how key features arising from
optical supersymmetry can be exploited to control the flow of light for mode
division multiplexing applications. Superpartner configurations are
experimentally realized in coupled optical networks, and the corresponding
light dynamics in such systems are directly observed. We show that SUSY can be
judiciously utilized to remove the fundamental mode of a multimode optical
structure, while establishing global phase matching conditions for the
remaining set of modes. Along these lines, supersymmetry may serve as a
promising platform for a new generation of versatile optical components with
novel properties and functionalities.Comment: 14 pages, 4 figure
Serological and Molecular Identification of Brucella spp. in Pigs from Cairo and Giza Governorates, Egypt
Brucellosis is considered as endemic disease of animals and humans since thousands of years in Egypt. However, brucellosis in pigs has never been reported in Egypt. Thus, serological and molecular assays were applied to detect anti-Brucella antibodies and DNA in serum samples collected from pigs. In total 331 blood samples collected from male and female pigs at slaughterhouses of Cairo and Giza governorates were investigated using Brucella c- and i-ELISA and Brucella real-time PCR. Anti-Brucella antibodies were detected in 16 (4.83%) and 36 (10.8%) sera by i-ELISA and c-ELISA, respectively. Brucella DNA was detected in 10 (3.02%) seropositive samples and identified as Brucella melitensis (7/10) and Brucella suis (3/10). A higher prevelance was found in boars. This is the first study investigating pig brucellosis in Egypt. The results of this study will raise awareness for brucellosis in these farm animals and will help to develop effective control strategies
Use of serology and real time PCR to control an outbreak of bovine brucellosis at a dairy cattle farm in the Nile Delta region, Egypt
Epidemiological, molecular characterization and antibiotic resistance of Salmonella enterica serovars isolated from chicken farms in Egypt
Background Salmonella is one of major causes of foodborne outbreaks globally.
This study was conducted to estimate the prevalence, typing and antibiotic
susceptibilities of Salmonella enterica serovars isolated from 41 broiler
chicken farms located in Kafr El-Sheikh Province in Northern Egypt during
2014–2015. The clinical signs and mortalities were observed. Results In total
615 clinical samples were collected from broiler flocks from different organs
(liver, intestinal content and gall bladder). Salmonella infection was
identified in 17 (41%) broiler chicken flocks and 67 Salmonella isolates were
collected. Recovered isolates were serotyped as 58 (86.6%) S. enterica serovar
Typhimurium, 6 (9%) S. enterica serovar Enteritidis and 3 (4.5%) were non-
typable. The significant high mortality rate was observed only in 1-week-old
chicks. sopE gene was detected in 92.5% of the isolates which indicating their
ability to infect humans. All S. enterica serovar Enteritidis isolates were
susceptible to all tested antimicrobials. The phenotypically resistant S.
enterica serovar Typhimurium isolates against ampicillin, tetracycline,
sulphamethoxazole and chloramphenicol were harbouring BlaTEM, (tetA and tetC),
(sul1 and sul3) and (cat1 and floR), respectively. The sensitivity rate of S.
enterica serovar Typhimurium to gentamycin, trimethoprim/sulphamethoxazole and
streptomycin were 100, 94.8, 89.7%, respectively. The silent streptomycin
antimicrobial cassettes were detected in all Salmonella serovars. A class one
integron (dfrA12, orfF and aadA2) was identified in three of S. enterica
serovar Typhimurium strains. Conclusions To the best of our knowledge, this
study considered first report discussing the prevalence, genotyping,
antibiotic susceptibility and public health significance of S. enterica
serovars in broilers farms of different ages in Delta Egypt. Further studies
are mandatory to verify the location of some resistance genes that are within
or associated with the class one integron
Identification, Genotyping and Antimicrobial Susceptibility Testing of Brucella spp. Isolated from Livestock in Egypt
Brucellosis is a highly contagious zoonosis worldwide with economic and public health impacts. The aim of the present study was to identify Brucella (B.) spp. isolated from animal populations located in different districts of Egypt and to determine their antimicrobial resistance. In total, 34-suspected Brucella isolates were recovered from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats from nine districts in Egypt. The isolates were identified by microbiological methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Differentiation and genotyping were confirmed using multiplex PCR for B. abortus, Brucella melitensis, Brucella ovis, and Brucella suis (AMOS) and Bruce-ladder PCR. Antimicrobial susceptibility testing against clinically used antimicrobial agents (chloramphenicol, ciprofloxacin, erythromycin, gentamicin, imipenem, rifampicin, streptomycin, and tetracycline) was performed using E-Test. The antimicrobial resistance-associated genes and mutations in Brucella isolates were confirmed using molecular tools. In total, 29 Brucella isolates (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were identified and typed. The resistance of B. melitensis to ciprofloxacin, erythromycin, imipenem, rifampicin, and streptomycin were 76.2%, 19.0%, 76.2%, 66.7%, and 4.8%, respectively. Whereas, 25.0%, 87.5%, 25.0%, and 37.5% of B. abortus were resistant to ciprofloxacin, erythromycin, imipenem, and rifampicin, respectively. Mutations in the rpoB gene associated with rifampicin resistance were identified in all phenotypically resistant isolates. Mutations in gyrA and gyrB genes associated with ciprofloxacin resistance were identified in four phenotypically resistant isolates of B. melitensis. This is the first study highlighting the antimicrobial resistance in Brucella isolated from different animal species in Egypt. Mutations detected in genes associated with antimicrobial resistance unravel the molecular mechanisms of resistance in Brucella isolates from Egypt. The mutations in the rpoB gene in phenotypically resistant B. abortus isolates in this study were reported for the first time in Egypt
Characterization of Enterococci- and ESBL-Producing Escherichia coli Isolated from Milk of Bovides with Mastitis in Egypt
This study aimed to investigate the prevalence and antimicrobial resistance of enterococci- and ESBL-producing E. coli isolated from milk of bovine mastitis cases in Egypt. Fifty milk samples of dairy animals were collected from localities in the Nile Delta region of Egypt. Isolates were identified using MALDI-TOF MS, and antibiotic susceptibility testing was performed by the broth microdilution method. PCR amplifications were carried out, targeting resistance-associated genes. Seventeen Enterococcus isolates and eight coliform isolates could be cultivated. Vancomycin resistance rate was high in Ent. faecalis. The VITEK 2 system confirmed all E. coli isolates as ESBL-producing. All Ent. faecalis isolates harbored erm(B), tetL and aac-aphD genes. The vanA gene was detected in Ent. faecalis isolate, vanB was found in other Enterococcus, while one isolate of E. casseliflavus exhibited the vanA gene. E. coli isolates exhibited high prevalence of erm(B) and tetL. E. coli isolates were analyzed by DNA microarray analysis. Four isolates were determined by O-serotyping as O8 (n = 1), O86 (n = 2) and O157 (n = 1). H-serotyping resulted in H11, H12, H21 (two isolates each) and one was of H16 type. Different virulence-associated genes were detected in E. coli isolates including lpfA, astA, celB, cmahemL, intI1 and intI2, and the iroN gene was identified by DNA microarray analysis
Characterization of Methicillin-Resistant Staphylococcus aureus Isolated from Healthy Turkeys and Broilers Using DNA Microarrays
Methicillin-resistant Staphylococcus aureus (MRSA) is a major human health
problem and recently, domestic animals are described as carriers and possible
reservoirs. Twenty seven S. aureus isolates from five turkey farms (n = 18)
and two broiler farms (n = 9) were obtained by culturing of choana and skin
swabs from apparently healthy birds, identified by Taqman-based real-time
duplex nuc-mecA-PCR and characterized by spa typing as well as by a DNA
microarray based assay which covered, amongst others, a considerable number of
antibiotic resistance genes, species controls, and virulence markers. The
antimicrobial susceptibility profiles were tested by agar diffusion assays and
genotypically confirmed by the microarray. Five different spa types (3 in
turkeys and 2 in broilers) were detected. The majority of MRSA isolates
(24/27) belonged to clonal complex 398-MRSA-V. The most frequently occurring
spa types were accordingly t011, t034, and t899. A single CC5-MRSA-III
isolated from turkey and CC398-MRSA with an unidentified/truncated SCCmec
element in turkey and broiler were additionally detected. The phenotypic
antimicrobial resistance profiles of S. aureus isolated from both turkeys and
broilers against 14 different antimicrobials showed that all isolates were
resistant to ampicillin, cefoxitin, oxacillin, doxycycline, and tetracycline.
Moreover, all S. aureus isolated from broilers were resistant to erythromycin
and azithromycin. All isolates were susceptible to gentamicin,
chloramphenicol, sulphonamides, and fusidic acid. The resistance rate against
ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All
tetracycline resistant isolates possessed genes tetK/M. All erythromycin-
resistant broiler isolates carried ermA. Only one broiler isolate (11.1%)
carried genes ermA, ermB, and ermC, while 55.6% of turkey isolates possessed
ermA and ermB genes. Neither PVL genes (lukF/S-PV), animal-associated
leukocidin (lukM and luk-P83) nor the gene encoding the toxic shock syndrome
toxin (tst1) were found in turkey and broiler isolates. In conclusion, the
detection of MRSA in healthy turkeys and broilers with even additional
antibiotic resistance markers is of major public health concern. The
difference in antibiotic resistance and virulence markers between MRSA
isolates from turkeys and broilers was addressed
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