35 research outputs found
Detection of extended-spectrum beta-lactamase genes among Escherichia coli isolates from urinary tract infection in Mashhad
Urinary tract infections (UTIs) are known as one of the most important infections around the world, and Escherichia coli is the most important cause of UTI. Also, the empiric treatment and misusing of antimicrobial agents has led to increasing multi-drug resistance around the world which is a worldwide concern. Extended-spectrum beta-lactamase (ESBLs) is an enzyme group that is produced by the Enterobacteriaceae family. The three main ESBLs enzyme are as follow: blaCTX-M, blaTEM, and blaSHV, additionally, there are several types of each of them by the same mechanism. This study was conducted to evaluate the prevalence of ESBL genes among E. coli isolated from UTI patients. A total of 105 isolates were collected from UTI patients at two hospitals in Mashhad from 2017 to 2019. Bacterial identification was performed by standard microbiologic methods. The assessment of antimicrobial susceptibility was accomplished by the disk diffusion method. The presence of ESBL genes was investigated by multiplex-PCR. The prevalence of UTI, among females, was identified more than males. Furthermore, the blaTEM and blaCTX-M genes were detected in all isolates, but only six isolates (5.7%) were harboring blaSHV. The considerable role of E. coli in UTI infection, as well as the presence of ESBL genes in E. coli strains, emphasize the need for surveillance of antimicrobial therapy to prevent the extension of resistance among clinical strains
Detection of cadmium acute toxicity in oyster, Crassostrea sp.
Heavy metals in high concentrations in the environment, is caused serious damage in metabolic, physiologic and structural organisms. Cadmium as the second most toxic metal in marine environments is considered. Bivalvia especially oysters are Suitable bioindicators due to its high filtration rates, immobility and lack of regulatory systems for removing of heavy metals. Crassostrea sp. is new species has wide distribution in Bandar Emam Khomeini. This species is the best for using toxicity testing to determine the effects of heavy metal pollutants in the environment. The aim this study is determination of Medium Lethal Concentration (LC5096h), Maximum Allowable Toxicant Concentration (MATC) and Lowest Observed Effect Concentration (LOEC) of Cadmium in Crassostrea sp. oyster. Fifty oysters (5.3±0.76 gr) were collected from Bandar Emam Khomaini and transported to laboratory. After Acclimatization (for 7 days), the 96-h LC_50 tests were conducted (static Method) according to standard instruction O.E.C.D. The 96 h LC_50, NOEC and LOEC were 15.8, 1.58 and 2.9 mg/l respectively. The LC_50 correlation whit in 24 h and 96 h were showed Linear equation y=-0.4225x+54.35
Chromosomal Analysis Of Couples With Bad Obstetric Histoty
ABSTRACT Background and Objective: Pregnancy termination and recurrent abortion are one of th
Selection of peptides from random peptide libraries for a recombinant vaccine against dermatophilosis
Dermatophilosis commonly known as "lumpy wool" in sheep in Australia, is a skin disease of animals and man caused by Dermatophilus congolensis. In sheep dermatophilosis causes significant wool production losses both directly and indirectly due to down grading of wool and hides, low meat production and high mortality. particularly in young sheep. Control of the disease by vaccination is desirable but has only been partially successful and antigens are difficult to produce in sufficient quantity from D. congolensis. Dr T.M. Ellis and colleagues (Agriculture WA) have developed a vaccine that can produce a significant reduction in ovine dermatophilosis against several strains of the bacterium. In pen and field studies, the haemolysin based vaccine did not prevent initial infection but approximately 70% were protected against the development of lumpy wool. Their previous research showed that a vaccine prepared from a serine protease produced by D. congolensis also gave some protection against the disease. This antigen was expensive to prepare by conventional culture.
An alternative approach is to use recombinant protein as an antigen. However, this is not a simple task if the protective antigens have not been identified and even if they have been, it can be difficult to prepare a recombinant protein in high yield. Random peptide libraries provide an alternative approach to the identification of peptides which might be useful in a vaccine. While these libraries have been used to identify epitopes and prepare diagnostic tests, their potential to produce antigens which could generate a protective immune response has still to be explored. The main aim of this thesis was to use random peptide libraries to identify new antigens which could be used in the future to immunise sheep and other animals against dermatophilosis.
Because of the commercial availability of large random peptide libraries displayed on phage and flagellin there is an opportunity to produce low cost and immunologically potent peptide vaccines. To explore the effectiveness and reliability of random peptide libraries (Ph.D.â„¢ and FliTrxTM libraries) for the selection of peptides, polyclonal antibodies against a recombinant serine protease from D. congolensis were used to pan the libraries. This recombinant serine protease was produced using a pQE expression vector and purified by immobilised metal affinity chromatography. Clones selected from the libraries were sequenced and the peptides aligned with the original amino sequence of serine protease. Many of the peptides aligned with varying homology to the serine protease sequence which demonstrated that the antibodies were selecting specific sequences from the libraries rather than just random peptides.
To obtain peptides, which might be associated with a protective immune response to D. congolensis sheep which had been immunised with a crude enzyme preparation form D. congolensis by Dr T.M. Ellis were used as a source of antibodies.
Four peptides from Ph.D.TM and three peptides from FliTrxâ„¢ libraries were chosen for vaccination of sheep. Sheep were given two doses of vaccine one month apart. Twentyone days after the second vaccination each sheep was challenged with a zoospore suspension of the MB and W14 strains of D. congolensis and the presence of lesions and their severity were measured at 7, 14 and 21 days after challenge. The immune response to D. congolensis antigens was also studied. There was a striking production of antibodies to antigens from D. congolensis induced by the peptides selected from the random peptide libraries. Vaccination with recombinant serine protease and with the peptides selected from the Ph.D.â„¢ library increased the rate of resolution of the lesions caused by one strain of D. congolensis.
The results in this thesis provide the first demonstration in large animals that phage displayed peptides can induce a specific immune response against an infectious agent
The effect of mouse embryonic fibroblast in direct differentiation of mouse embryonic stem cells
Background: Since embryonic stem (ES) cells have the dual ability to
proliferate indefinitely and differentiate into multiple tissue types,
ES cells could potentially provide an unlimited cell supply for human
transplantation. Objective: In order to study the differentiation of
mouse embryonic stem (mES) cells, they were cultured in suspension by
using ES media without Leukemia Inhibitory Factor (LIF) to induce
spontaneous differentiation. Cellular morphology of differentiated
derivatives was then evaluated. Materials and Methods: Undifferentiated
mES from our laboratory were cultured in three different settings by
using ES media containing 0.1% / 1mM trypsin/EDTA and removing LIF; in
the absence of murine embryonic fibroblast (MEF) feeder cells (group
1), in the presence of MEF feeder cells with a density of 0.5×105
cells/ml (group 2), and 0.5×106 cells/ml (group 3). Five days
after the initiation of cell culture, and inducing mES cells to form
embryoid bodies (EBs), they were removed from dish by centrifugation,
and then they were cultured on collagen coated dishes for 20 days. The
dishes were fixed and stained by Wright-Gimsa method at the end of the
study period. Results: In group 1, mES cells showed spontaneous
differentiation to all derivatives of three germ cells, including:
epithelia like, fibroblast like and neron-like cells. In group 2,
almost all ES cells were found to be differentiated into granular
progenitor cells including hematopoietic cell lineages. In group 3,
various morphologies including nerve cell lineages and fibroblast-like
cells were detected. Conclusion: Differentiation of mES cells can be a
dose response process, depending on the factors that may be released
from MEF feeder layer to ES media in a coculture system. Our results
indicated that in the presence of low numbers of MEF cells, mES cells
can spontaneously differentiate into hematopoeitic cell lineages
Prevalence of Bovine Viral Diarrhoea Virus antibodies and antigen among the aborted cows in industrial dairy cattle herds in Mashhad area of Iran
The measurement of antibody responses of animals exposed to BVDV either through a natural exposure or an immunization protocol is still a standard procedure. For BVDV, the test formats have been largely limited to ELISA which is a valuable diagnostic test to measure the level of BVDV specific antibodies as well as antigen in blood samples. In the present study, 120 blood samples were collected from the cows with the history of abortion in different period of pregnancy from different industrial dairy cattle herds of Mashhad area of Iran. Also 30 samples were collected from the cows with no history of abortion as control. The presence of antibody against BVDV from the 120 serum samples was investigated by indirect ELISA. From 120 serum samples which were collected from aborted cows, 89 samples were positive (%74.16). From these positive samples, 12(13.48%), 54 (60.68%) and 23 (25.84%) samples belong to the first, second and third trimester of pregnancy, respectively. From 89 positive samples, 12 (13.48%) samples were related to stillbirth and 8 (8.99%) samples were belongs to the mummified fetus. From 89 positive samples, 71 (79.78%) were related to cattle between 2-5 years old and 18 (20.22%) were associated to cattle more than 5 years old. In control group, 20 samples (66.66%) were antibody positive. Also the presence of BVDV antigen in serum samples was investigated by Ag-capture ELISA. From 120 serum samples, 2 samples were positive (1.67%), which belongs to the second period of pregnancy. In control group, none of the samples were antigen positive. The results of this study showed that the prevalence of BVDV infection is high among the aborted cows of Mashhad area. Although this prevalence is higher than the control group, the observed difference is not significant
Isolation and differentiation of mouse embryonic stem cells
Background: Recently, embryonic stem (ES) cells have become very
important resources in basic medical researches. These cells can
differetiate into derivatives of all primary germ layers. Objectives:
In order to isolate embryonic stem cells in vitro, the blastocyst were
cultured and the morphological aspects, population doubling time,
alkalin phosphatse and differentiation properties of the cells were
investigated. Materials and Methods: The balstocysts from NMRI mice
were cultured for 3 days up to time that inner cell mass (ICM) reach to
the outgrowth stage. The cells were disaggregated and trypsinized every
3 days until the appearance of the colonies of ES cells. The colony
positive cells were fixed and stained for alkaline phosphatase. The ES
cells were cultured in suspension state for 5 days, at the same time
Leukaemia Inhibitory Factor (LIF) was removed from media to form
embryoid bodies(EBs). The EBs were cultured for 8 - 20 days on collagen
coated dish to induce the spontaneouse differentiation. Results: During
the 6-9 days after the disaggregation of ICM in the expansion stage,
the colony of ES cells appeared as a flat monolayer mass with strike
boundaries and nondistinguish cytoplasm including a few nuclei. In
colony formation stage, the morphology changed from flat monolayer to
round multilayer with strike define boundaries. Undifferentiated cells
were seen as intensely small cells attached together compactly with
high nucleus/cytoplasm (N/C) ratio. The cells of colonies tend to
differetiate by separation from each other and became larger and
diffused on substrate by attaching to dish. The positive alkaline
phosphatase cells were seen in typical morphology of ES colonies. The
EBs cells were seen in culture after 5 days in suspension and began to
spontaneously differentiate into various types of cells such as nerve
and hematopoitic lineages. Conclusion: Despite strike morphology of ES
colonies, it is difficult to distinguish the differentiated from
undifferentiated cell colonies in the colony formation stage. New ES
cells are capable to give rise into EBs and are susceptible of
spontaneously differentiation in various type of cells
Effect Of Aqueous And Hydroalcoholic Extract Of Beberis Vulgaris On Insulin Secretion From Islets Of Langerhans Isolated From Male Mice
Background & Aim: considering the use of Beberis vulgaris in traditional medicine as a blood sugar depressant, in this study, the effect of Beberis vulgaris extracts were investigated on the level of insulin secretion from islets isolated of langerhans in male mice.
Methods: This experimental study was carried out on 90 adult male mice, NMARI strains weighing 20-25 g. Pancreatic islets from normal mice were isolated by collagenase digestion method. Then the aqueous and hydro-alcoholic extract of Beberis vulgaris at 0.05, 0.1, and 1 mg/ml concentrations and glyburide at 1 and 10 μM concentrations were applied on islets isolated in three different concentration of glucose solution (2.8, 5.6 and 16.7 mM). Insulin secretion from hand-picked islets were evaluated in the static incubation system. The level of Insulin secretion was measured by the ELISA insulin kit. Data were analyzed with variance analysis.
Results: Insulin secretion was significantly increased at 16.7 mM glucose concentration in comparison with 2.8 and 5.6 mM glucose concentration (p<0.05). Incubation of pancreatic islets isolated at 2.8 and 5.6 mM glucose concentration and low concentrations of extract (0.05 and 0.1mg/ml) significantly increased the insulin secretion (p<0.05). Glyburide at 10 μM concentration was more effective than aqueous and hydro alcoholic extract of Beberis vulgaris at 16.7 mM glucose.
Conclusion: The present study supported the anti-diabetic effect of Beberis vulgaris extracts in vitro with low glucose concentration and it suggests that one of the anti diabetic mechanisms of this plant is via pancreatic islets
Application of lysine imprinted polymer as carbon dioxide colorimetric indicators for food packaging
Carbon dioxide is highly produced by microbial spoilage of food. Thus, the freshness of the marketed products can be represented by sensors visually highlighting the existence of CO2 within the food packages as labels. In the present work, FTIR and SEM, and XRD were used to synthesize and characterize l-lysine imprinted polymers. Then, it was utilized as a biosensor for CO2 sensing under phenyl red. By investigating its performance under CO2 gas, its applicability was proved via this synthesized biosensor for spoilage monitoring of packaged minced beef. The aerobic psychrotrophic count (PTC), aerobic plate count (APC), and Enterobacteriaceae counts were monitored to assess the samples’ microbial quality in this period. The results revealed that the synthesized biosensor can act as a prevailing senor to monitor meat quality and imprint lysine on this polymer thus improving and catalyzing its reversible performance