We describe a spectral x-ray transmission method to provide images of independent material components of an object using a synchrotron x-ray source. The imaging system and process is similar to K-edge subtraction (KES) imaging where two imaging energies are prepared above and below the K-absorption edge of a contrast element and a quantifiable image of the contrast element and a water equivalent image are obtained. The spectral method, termed 'spectral-KES' employs a continuous spectrum encompassing an absorption edge of an element within the object. The spectrum is prepared by a bent Laue monochromator with good focal and energy dispersive properties. The monochromator focuses the spectral beam at the object location, which then diverges onto an area detector such that one dimension in the detector is an energy axis. A least-squares method is used to interpret the transmitted spectral data with fits to either measured and/or calculated absorption of the contrast and matrix material-water. The spectral-KES system is very simple to implement and is comprised of a bent Laue monochromator, a stage for sample manipulation for projection and computed tomography imaging, and a pixelated area detector. The imaging system and examples of its applications to biological imaging are presented. The system is particularly well suited for a synchrotron bend magnet beamline with white beam access.
A multiple energy imaging system that can extract multiple endogenous or induced contrast materials as well as water and bone images would be ideal for imaging of biological subjects. The continuous spectrum available from synchrotron light facilities provides a nearly perfect source for multiple energy x-ray imaging. A novel multiple energy x-ray imaging system, which prepares a horizontally focused polychromatic x-ray beam, has been developed at the BioMedical Imaging and Therapy bend magnet beamline at the Canadian Light Source. The imaging system is made up of a cylindrically bent Laue single silicon (5,1,1) crystal monochromator, scanning and positioning stages for the subjects, flat panel (area) detector, and a data acquisition and control system. Depending on the crystal's bent radius, reflection type, and the horizontal beam width of the filtered synchrotron radiation (20-50 keV) used, the size and spectral energy range of the focused beam prepared varied. For example, with a bent radius of 95 cm, a (1,1,1) type reflection and a 50 mm wide beam, a 0.5 mm wide focused beam of spectral energy range 27 keV-43 keV was obtained. This spectral energy range covers the K-edges of iodine (33.17 keV), xenon (34.56 keV), cesium (35.99 keV), and barium (37.44 keV); some of these elements are used as biomedical and clinical contrast agents. Using the developed imaging system, a test subject composed of iodine, xenon, cesium, and barium along with water and bone were imaged and their projected concentrations successfully extracted. The estimated dose rate to test subjects imaged at a ring current of 200 mA is 8.7 mGy s, corresponding to a cumulative dose of 1.3 Gy and a dose of 26.1 mGy per image. Potential biomedical applications of the imaging system will include projection imaging that requires any of the extracted elements as a contrast agent and multi-contrast K-edge imaging.
Aims: This study investigated the molecular diversity and extended spectrum beta-lactamase resistance of diarrheagenic E. coli isolated from patients attending selected healthcare facilities in Nasarawa State, Nigeria. Place and Duration of Study: Department of Microbiology, Nasarawa State University, P.M.B 1022, Keffi, Nasarawa State, Nigeria; between December 2017 and June, 2019. Methodology: A total of 207 confirmed E. coli isolates (using standard microbiological methods) from loose stool samples of patients with suspected cases of diarrhea (69 from Federal Medical Centre Keffi [MCK] 69 from General Hospital Akwanga [GHA] and 69 from Dalhatu Araf Specialist Hospital Lafia [DASHL]) were included in this study. Results: Phenotypic detection of ESBL production by β-lactam resistant isolates was done using double disc synergy test. Molecular detection of ESBL genes in phenotypically confirmed ESBL producers was done using Polymerase Chain Reaction. Out of 56 isolates jointly resistant to cefotaxime and/or ceftazidime and ciprofloxacin from DASHL, FMCK and GHA, 53.6% (30/56) were ESBL producers, distributed in relation to the hospitals as follows: blaCTX-M in DASHL was 6(66.7%), FMCK was 11(100.0%), and GHA was 10(100.0%); blaSHV in DASHL was 8(88.9%), FMCK was 7(63.6%), and GHA was 10(100.0%), and blaTEM in DASHL was 9(100.0%), FMCK was 10(90.9%), and GHA was 10(100.0%). Also, the occurrence of blaSHV was 100.0% in GHA but 88.9% in DASHL. The detection DEC was high in DASHL (88.9%) but low inGHA (58.8%). The occurrence of ETEC was high in GHA (60.0%) while EAEC was also high in FMCK (81.8%) and GHA (70.0%). The isolates were distributed into strain A – J based on RFLP pattern and the occurrence of strain A was high in GHA (70.0%) but low in DASHL (33.3%). Conclusion: Most of the isolates were both diarrheagenic and ESBL resistant, and the predominant ESBL and pathotypes genes were blaCTX-M, blaTEM and EAEC. Further studies on molecular detection of sub-types of ESBL and sequencing of diarrheagenic pathotypes genes should be carried out.
We evaluated the malaria burden in randomly selected pregnant women (PW) attending antenatal clinics in Abuja, Nigeria, to establish an association between pregnancies, malaria. Structured questionnaire was administered by the antenatal nursing staff and a research assistant. In total, 1400 pregnant women were screened between April and September 2004, and capillary blood samples were obtained and screened for malaria parasites in thin blood films and quantitative buffy coat analysis (QBC). In total, 1035 (73.9%) pregnant women were positive for Plasmodium falciparum; of which 578 (55.8%) were primigravidae; 299 (28.9%) second gravidae; and 158 (15.3%) were multigravidae, while 297 (28.7) were in their first trimester, 311 (30%) were in their second trimester, and 427 (41.3%) were in their third trimester. The highest prevalence of malaria parasite (31.6%) was found in those aged 26-30 years while the lowest prevalence (2.9%) occurred in those aged 41-46 years. Socio economically, prevalence of malaria parasite is highest in nonautomobile owners 84.4%, 66% in those with monthly income less than $100, and those living in vegetable thatched houses had 46.0%, while the lowest incidence (15.6%) was found in automobile owners. Of the 760 pregnant women who sought malaria treatment only 278 (34.2%) seek intervention in hospitals, while 59.4% got treatment outside the hospital or were on self medication. This study demonstrated a high prevalence of malaria in the population evaluated, and therefore underlines the need for urgent intervention through capacity building, implementation of intermittent preventive treatment (IPT), use of insecticides treated-nets (ITN) and effective case management of malaria illness. The delivery of these interventions through antenatal clinics in Nigeria is highly critical and needs to be encouraged; strategies that encourage pregnant women to attend antenatal clinics early and consistently need to be developed. It is also important to develop coherent and effective policies and tools to tackle malaria and poverty.
Aims: This study investigated the phenotypic detection of extended spectrum beta-lactamase resistance of diarrheagenic E. coli isolated from diarrheic patients attending some major health facilities in Nasarawa State, Nigeria. Place and Duration of Study: Department of Microbiology, Nasarawa State University, P.M.B 1022, Keffi, Nasarawa State, Nigeria; between December, 2017 to March, 2019. Methodology: A total of 207 confirmed E. coli isolates from loose stool samples of patients with suspected cases of diarrhea (69 from Federal Medical Centre Keffi [MCK] 69 from General Hospital Akwanga [GHA] and 69 from Dalhatu Araf Specialist Hospital Lafia [DASHL]) were included in this study. Results: E. coli was isolated and identified using standard microbiological methods. The antibiotic susceptibility testing for the isolates was carried out and interpreted in accordance with Clinical and Laboratory Standards Institute protocol. Phenotypic detection of ESBL production in isolates resistant to ciprofloxacin, cefotaxime and ceftazidime) was carried out using double disc synergy test. The occurrence of E. coli was 100% in all the hospitals. Age groups 0-5 and 6-10 years have the highest occurrence than age group 35 – >45 years. Isolates from DASHL were more resistant to amoxicillin/clavulanic acid (86.9%), Streptomycin (75.0%) and sulphamethoxazole/trimethoprim (68.1%), isolates from FMCK were more resistant to amoxicillin/clavulanic acid (84.1%), sulphamethoxazole/trimethoprim (69.6%), isolates from GHA were more resistant to amoxicillin/clavulanic acid (85.5%) and sulphamethoxazole/trimethoprim (73.0%). Multiple antibiotic resistance (MAR) was observed with the order of occurrence: FMCK (98.6%) > DASHL (92.8%) > GHA (89.9%). The most common MAR index of 0.2 in DASHL was 0.4 (20.3%); FMCK was 0.4 (15.9%) and GHA was 0.3 (17.4%). The order of occurrence of classes of antibiotic resistance in E. coli isolates in DASHL was MDR (84.0%) ˃ XDR(7.2%) > PDR and NMDR (4.3%); in FMCK was MDR (91.3%) ˃ XDR(4.3%) ˃ NMDR (2.9%) and PDR(1.4%); and in GHA was MDR (88.8%) ˃ NMDR(5.8%) > XDR and PDR(2.9%). Detection rate of ESBL was 53.6% (30/207), distributed in relation to the location as DASHL (60.0%), FMCK (50.0%) and GHA (52.6%). Conclusion: Most of the isolates from the study locations were antibiotic resistance. Further studies on molecular detection of ESBL, diversity and characterization of the E. coli into pathotypes are ongoing.
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