Fluorogenic Aptamer Optimizations on a Massively Parallel Sequencing Platform.

F luorogenic ap tamers (FAPs) have become an increasingly important tool in cellular sensing and pathogen diagnostics. However, fine-tuning FAPs for enhanced performance remains challenging even with the structural details provided by X-ray crystallography. Here we present a novel approach to optimize a DNA-based FAP (D-FAP), Lettuce, on repurposed Illumina next-generation sequencing (NGS) chips. When substituting its cognate chromophore, DFHBI-1T, with TO1-biotin, Lettuce not only shows a red-shifted emission peak by 53 nm (from 505 to 558 nm), but also a 4-fold bulk fluorescence enhancement. After screening 8,821 Lettuce variants complexed with TO1-biotin, the C14T mutation is found to exhibit an improved apparent dissociated constant ( vs. 0.82 µM), an increased quantum yield (QY: 0.62 vs. 0.59) and an elongated fluorescence lifetime (τ: 6.00 vs. 5.77 ns), giving 45% more ensemble fluorescence than the canonical Lettuce/TO1-biotin complex. Molecular dynamic simulations further indicate that the π-π stacking interaction is key to determining the coordination structure of TO1-biotin in Lettuce. Our screening-and-simulation pipeline can effectively optimize FAPs without any prior structural knowledge of the canonical FAP/chromophore complexes, providing not only improved molecular probes for fluorescence sensing but also insights into aptamer-chromophore interactions.

Engineering biomimetic scaffolds for bone regeneration: Chitosan/alginate/polyvinyl alcohol-based double-network hydrogels with carbon nanomaterials.

In this study, new types of hybrid double-network (DN) hydrogels composed of polyvinyl alcohol (PVA), chitosan (CH), and sodium alginate (SA) are introduced, with the hypothesis that this combination and incorporating multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) will enhance osteogenetic differentiation and the structural and mechanical properties of scaffolds for bone tissue engineering applications. Initially, the impact of varying mass ratios of the PVA/CH/SA mixture on mechanical properties, swelling ratio, and degradability was examined. Based on this investigation, a mass ratio of 4:6:6 was determined to be optimal. At this ratio, the hydrogel demonstrated a Young's modulus of 47.5 ± 5 kPa, a swelling ratio of 680 ± 6 % after 3 h, and a degradation rate of 46.5 ± 5 % after 40 days. In the next phase, following the determination of the optimal mass ratio, CNTs and GNPs were incorporated into the 4:6:6 composite resulting in a significant enhancement in the electrical conductivity and stiffness of the scaffolds. The introduction of CNTs led to a notable increase of 36 % in the viability of MG63 osteoblast cells. Additionally, the inhibition zone test revealed that GNPs and CNTs increased the diameter of the inhibition zone by 49.6 % and 52.6 %, respectively.

Fabrication of gelatin-based antibacterial bilayer wound dressing using direct writing and electrospinning methods.

Fabricating a fibrous well-ordered wound dressing for accelerating full-thickness wounds is a desirable treatment vector. Here, through modifications in the material extrusion device and adding a pneumatic-based injection, a material extrusion method for gelatin was introduced with the ability to fabricate 3D structure with repeat layers to support cell activity for the under layer. Furthermore, in the upper layer, the co-electrospinning of PU with gelatin was designed to simultaneously exploit the oxygen permeability and mechanical stability of PU with regenerative properties and collagen-like structure of gelatin. Moreover, zinc oxide nanoparticles (ZnO) was added into the 3D-printed under layer to synergistically benefit from the antibacterial properties of ZnO and the excellent biocompatibility of gelatin. The controllable porosity of the under layer, enabled through the additive manufacturing method, was adjusted to mimic the extracellular matrix of natural tissue with around (127.28 ± 20.70) µm pore size after swelling with smooth fibers. S. aureus, E. coli, Bacillus subtilis, and Pseudomonas with inhibition zone diameters at âˆ¼ 2.14 cm and âˆ¼ 1.96 cm, ∼ 4.01 cm, and âˆ¼ 2.24 cm, respectively. Moreover, the scaffold showed great biocompatibility toward fibroblast cells after 7 days of cell culture with âˆ¼ 89 % cell viability.

Protective effect of nanocurcumin on acetaminophen-induced hepatic and renal toxicities in pigeons.

In this study, the effects of nanocurcumin on acetaminophen-induced acute hepatorenal toxicity in domestic pigeons (Columba livia) were investigated. Fifteen pigeons were randomly assigned into three groups. Group I was served as a negative control group and received tap water as a placebo. Pigeons in groups II and III were administered acetaminophen at the beginning of the experiment (hr 0). Group III was further treated with nanocurcumin, at 12 hr after acetaminophen administration, being continued every 12 hr for two days. The birds were observed for clinical signs of acute drug toxicity. Blood samples were collected from the pigeons at hr 0, 12, 24 and 48 of the experiment for biochemical analysis of the serum. The results showed that acetaminophen toxicity increased the serum levels of aspartate aminotransferase, alanine aminotransferase, urea and uric acid in the pigeons. Nanocurcumin treatment of acetaminophen intoxicated pigeons attenuated increases in biomarkers of the liver and kidney functions towards control levels. Also, the consumption of nanocurcumin minimized histopathological changes in the liver and kidney. A mortality of 60.00% was seen in the acetaminophen-induced toxicity group; while, none of the birds treated with nanocurcumin died. It can be concluded that nanocurcumin alleviates the acetaminophen-induced acute toxic liver and kidney damages, which can lead to pigeon mortality.

Fabrication of heparinized bi-layered vascular graft with PCL/PU/gelatin co-electrospun and chitosan/silk fibroin/gelatin freeze-dried hydrogel for improved endothelialization and enhanced mechanical properties.

Fabricating a biocompatible small-diameter vascular graft (< 6 mm) with mechanical properties similar to the natural vein and adding good anti-thrombogenic, endothelialization, and hyperplasia properties remains a challenge. To this end, we fabricated a heparinized bilayer graft to address this problem. The proposed bilayer sample consisted of a heparinized polycaprolactone (PCL), polyurethane (PU), and gelatin (G) co-electrospun inner layer and chitosan, gelatin, and silk fibroin freeze-dried hydrogel crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) outer layer. The samples exhibited great ultimate stress, Young's module, and suture retention of 4.16±0.25MPa, 8.24±2.59MPa and 4.83±0.31N, respectively. The heparin release assay indicated a sustained release profile of around 70% after 4weeks, which can be attributed to the excellent control via emulsion. Furthermore, the heparinized samples demonstrated good anti-thrombogenic properties investigated in the platelet adhesion assay. For the outer layer, the hydrogel crosslinked with non-toxic materials was prepared through the freeze-drying method to achieve high porosity (64.63%), suitable for smooth muscle cell activity. Moreover, inner and outer layers showed high cell viability toward endothelial (78.96%) and smooth muscle cells (57.77%), respectively. Overall, the proposed heparinized graft exhibited excellent potential for vascular graft regeneration.

A novel multifunctional chitosan-gelatin/carboxymethyl cellulose-alginate bilayer hydrogel containing human placenta extract for accelerating full-thickness wound healing.

The replication of skin's dermal and epidermal morphology within a full-thickness wound using a bi-layer hydrogel to cater to their distinct needs is a compelling pursuit. Moreover, human placenta extract (HPE), containing a diverse array of bioactive agents, has proven to be effective in promoting the wound healing process and enhancing epidermal keratinocytes. This study presents a multifunctional bi-layer hydrogel incorporating HPE for accelerating full-thickness wound healing through sustained HPE release, inhibition of bacteria invasion, and promotion of cell proliferation. The upper layer of the scaffold, known as the dressing layer, is composed of carboxymethyl cellulose and sodium alginate, serving as a supportive layer for cell proliferation. The under layer, referred to as the regenerative layer, is composed of chitosan and gelatin, providing an extracellular matrix-like, porous, moist, and antibacterial environment for cell growth. The scaffold was optimized to replicate the morphology of the dermal and epidermal layers, with suitable fibroblast infiltration and a pore size of approximately 283µm. Furthermore, the degradation rate of the samples matched the wound healing rate and persisted throughout this period. The sustained HPE release rate, facilitated by the degradation rate, was optimized to reach ~98% after 28 days, covering the entire healing period. The samples demonstrated robust antibacterial capabilities, with bacterial inhibition zone diameters of and 2.63±0.12cm for S. aureus and E. coli, respectively. The biocompatibility of the samples remained at approximately 68.33±4.5% after 21 days of fibroblast cell culture. The in vivo experiment indicated that the HPE@Bilayer hydrogel promotes the formation of new blood vessels and fibroblasts during the early stages of healing, leading to the appropriate formation of granulation tissue and a wound contraction rate of (79.31±3.1)%. Additionally, it resulted in the formation of a thick epidermal layer (keratinization) that effectively covered all the impaired areas, achieving a wound contraction rate of 95.83±6.3% at the late stage of wound healing. Furthermore, immunohistochemistry staining for CD31 and TGF-ß revealed that the HPE@Bilayer group had 22 blood vessels/field and 34%-66% immunoactive cells, respectively, after 14 days of healing. However, by day 21, angiogenesis and TGF-ß expression had declined, demonstrating that the wounds had been successfully treated with minimal scarring.

Investigating the correlation between the protein adhesion simulation and the biocompatibility of polymeric substrate for skin-tissue-engineering applications.

Investigating the protein adhesion properties of polymeric scaffolds through computational simulations can predict the biocompatibility of scaffolds before an experimental assay is carried out. This prediction can be highly beneficial since it can cut costs and the time it takes for experimental assays. The current study aims to test the hypothesis that there is a correlation between the biocompatibility of a composite scaffold and the molecular dynamics simulations of protein adhesion. To this end, chitosan and gelatin were selected for fabricating a composite skin-tissue wound scaffold with five different polymer ratios. This polymeric blend has not been simulated for protein adhesion. The cell proliferation and viability of the samples were quantified via MTT assay using fibroblast cells. Then a series of molecular dynamics simulations were performed to measure the adhesion energy of two prominent extracellular matrix proteins - fibronectin, and collagen type I. Besides, a higher gelatin percentage in the scaffold leads to a decrease in the porosity. The results demonstrated a strong correlation between the experimental data and molecular dynamics simulations. The sample with equal amounts of chitosan and gelatin had the highest cell viability and the strongest adhesion energy, of 239 kcal mol-1 for collagen type I, and 149 kcal mol-1 for fibronectin. This correlation was also evident in other samples: samples with gelatin-to-chitosan ratios of 3 : 1 and 1 : 3 had the lowest cell viability and the weakest adhesion energy, respectively.

Novel bilayer coating on gentamicin-loaded titanium nanotube for orthopedic implants applications.

Fabricating a multifunctional orthopedic implant which prevents post-surgery infection is highly desirable in advanced materials applications. However, designing an antimicrobial implant, which simultaneously promotes a sustained drug release and satisfactory cell proliferation, remains a challenge. The current study presents a drug-loaded surface-modified titanium nanotube (TNT) implant with different surface chemistry which was developed to investigate the effect of surface coating on drug release, antimicrobial activity, and cell proliferation. Accordingly, sodium alginate and chitosan were coated on the surface of TNT implants with different coating orders through layer-by-layer assembly. The coatings' swelling ratio and degradation rate were around 613% and 75%, respectively. The drug release results showed that surface-coatings prolonged the releasing profile for about 4 weeks. Chitosan coated TNTs demonstrated greater inhibition zone at 16.33mm compared with the other samples where no inhibition zone was observed. However, chitosan and alginate coated TNTs exhibited smaller inhibition zones at 48.56mm and 43.28mm, respectively, compared to bare TNT, which can be attributed to the coatings preventing the antibiotic burst release. Higher viability of cultured osteoblast cells was observed for chitosan-coated TNT as the top layer compared to the bare TNT at 12.18%, indicating improved bioactivity of TNT implants when the chitosan has the most contact with cells. Coupled with the cell viability assay, molecular dynamics (MD) simulations were carried out by placing collagen and fibronectin near the considered substrates. In agreement with cell viability results, MD simulations also indicated that chitosan had the highest adsorption energy approximately 60Kcal/mol. In summary, the proposed bilayer chitosan-coated drug-loaded TNT implant with chitosan and sodium alginate coating as the top and the bottom layers, respectively, can be a potential candidate for orthopedic applications in the light of its bacterial biofilm prevention, better osteoconductivity, and providing an adequate drug release profile.

Melt electrowriting of PLA, PCL, and composite PLA/PCL scaffolds for tissue engineering application.

Fabrication of well-ordered and bio-mimetic scaffolds is one of the most important research lines in tissue engineering. Different techniques have been utilized to achieve this goal, however, each method has its own disadvantages. Recently, melt electrowriting (MEW) as a technique for fabrication of well-organized scaffolds has attracted the researchers' attention due to simultaneous use of principles of additive manufacturing and electrohydrodynamic phenomena. In previous research studies, polycaprolactone (PCL) has been mostly used in MEW process. PCL is a biocompatible polymer with characteristics that make it easy to fabricate well-arranged structures using MEW device. However, the mechanical properties of PCL are not favorable for applications like bone tissue engineering. Furthermore, it is of vital importance to demonstrate the capability of MEW technique for processing a broad range of polymers. To address aforementioned problems, in this study, three ten-layered box-structured well-ordered scaffolds, including neat PLA, neat PCL, and PLA/PCL composite are fabricated using an MEW device. Printing of the composite PLA/PCL scaffold using the MEW device is conducted in this study for the first time. The MEW device used in this study is a commercial fused deposition modeling (FDM) 3D printer which with some changes in its setup and configuration becomes prepared for being used as an MEW device. Since in most of previous studies, a setup has been designed and built for MEW process, the use of the FDM device can be considered as one of the novelties of this research. The printing parameters are adjusted in a way that scaffolds with nearly equal pore sizes in the range of 140 µm to 150 µm are fabricated. However, PCL fibers are mostly narrower (diameters in the range of 5 µm to 15 µm) than PLA fibers with diameters between 15 and 25 µm. Unlike the MEW process of PCL, accurate positioning of PLA fibers is difficult which can be due to higher viscosity of PLA melt compared to PCL melt. The printed composite PLA/PCL scaffold possesses a well-ordered box structure with improved mechanical properties and cell-scaffold interactions compared to both neat PLA and PCL scaffolds. Besides, the composite scaffold exhibits a higher swelling ratio than the neat PCL scaffold which can be related to the presence of less hydrophobic PLA fibers. This scaffold demonstrates an anisotropic behavior during uniaxial tensile test in which its Young's modulus, ultimate tensile stress, and strain to failure all depend on the direction of the applied tensile force. This anisotropy makes the composite PLA/PCL scaffold an exciting candidate for applications in heart tissue engineering. The results of in-vitro cell viability test using L929 mouse murine fibroblast and human umbilical vein endothelial (HUVEC) cells demonstrate that all of the printed scaffolds are biocompatible. In particular, the composite scaffold presents the highest cell viability value among the fabricated scaffolds. All in all, the composite PLA/PCL scaffold shows that it can be a promising substitution for neat PCL scaffold used in previous MEW studies.

Investigation of the motion of fullerene-wheeled nano-machines on thermally activated curved gold substrates.

The current study presents one of the first investigations in which the simultaneous effect of the curved gold substrates and temperature changes on C60 and C60-wheeled nano-machines' migration was evaluated. For this aim, the cylindrical and concave substrates with different radii were chosen to attain the size of the most appropriate substrate for nano-machines. Results indicated that the chassis' flexibility substantially affected the nanocar's mobility. Nano-machines' deviation from their desired direction was adequately restricted due to selected substrate geometries (The cylindrical and concave). Besides, for the first time, the effect of the substrate radius changes on nano-machine's motion has been investigated. Our findings revealed that adjusting the value of radius results in a long-range movement for nano-machines as well as a sufficient amount of diffusion coefficient even at low temperatures ([Formula: see text] or [Formula: see text]). As a result, the aforementioned substrates could be utilized as the optimized geometries for C60 and nanocar at all temperatures. At the same time, the nanotruck displayed an appropriate performance merely on the small cylindrical substrate ([Formula: see text]) at high temperatures ([Formula: see text] and [Formula: see text]).

Investigation of fullerene motion on thermally activated gold substrates with different shapes.

In the current study, the regime of motion of fullerene molecules on substrates with different shapes at a range of specific temperatures has been investigated. To do so, the potential energy of fullerene molecules was analyzed using the classical molecular dynamics method. C20, C36, C50, C60, C72, C76, C80, and C90 fullerene molecules were selected due to their spherical shapes with different sizes. In addition, to completely analyze the behavior of these molecules, different gold substrates, including flat, concave, the top side of the step (upward step), and the downside of the step (downward step) substrates, were considered. Specifying the regime of the motion at different temperatures is one of the main goals of this study. For this purpose, we have studied the translational and rotational motions of fullerene molecules independently. In the first step of the investigation, Lennard-Jones potential energy of fullerene molecules was calculated. Subsequently, the regime of motion of different fullerenes has been classified, based on their displacement and sliding velocity. Our findings indicated that C60 is appropriate in less than [Formula: see text] of the conditions. However, C20, C76 and C80 molecules were found to be appropriate candidates in most cases in different conditions while they were incompetent only in seven situations. As far as a straight-line movement is considered, the concave geometry demonstrated a better performance compared to the other substrates. In addition, C72 indicated less favorable performance concerning the range of movement and diffusion coefficients. All in all, our investigation helps to understand the performance of different fullerene molecules on gold substrates and find their probable application, especially as a wheel in nano-machine structures.

Protective effects of Aloe vera powder supplementation on some quantitative and qualitative characteristics of egg, histopathological changes and serum biochemistry of laying hens fed by Aflatoxin B1.

In the recent years, the use of medicinal plants to reduce the effects of mycotoxins in foods and feeds has been considered. This study was conducted to investigate the effects of Aloe vera on performance, serum biochemical parameters and liver histopathology in laying hens fed on aflatoxin B1 (AFB1)-contaminated diet. Seventy-two White Leghorns (Hy-Line W-36) were randomly allocated to four treatments. 1) basal diet (control), 2) control plus 1.00 mg kg-1 AFB1, 3) control diet plus 1.00 mg kg-1 AFB1 + 100 ppm Aloe vera powder, and 4) control diet plus 1.00 mg kg-1 AFB1 + 300 ppm Aloe vera powder. Each treatment consisted of three replicates of 6 birds. Egg weight and Haugh units were not affected by AFB1. Egg production and eggshell thickness were lower for groups fed 1.00 mg kg-1 AFB1. Egg production, egg weight and eggshell thickness were improved by incorporation of Aleo vera in the AFB1 contaminated feed but were not significant. Chickens fed AFB1 had significantly lower aspartate aminotransferase (AST), alanine aminotransferase (ALT) and uric acid and higher cholesterol than other groups. Aloe vera powder improved levels of cholesterol, uric acid, AST, and ALT. AFB1 also caused histopathological changes in liver tissues, such as vacuolar degeneration, fatty infiltration, and necrosis. The addition of Aloe vera powder to the aflatoxin containing diet reduced the severity of lesions in liver. The data demonstrated the ability of Aloe vera to reduce the adverse effects of AFB1 exposure in laying hens.

Pathomorphologial investigation of spondylolisthesis leaded to spondylosis in commercial broiler chicken with posterior paralysis: A case study.

Spondylolisthesis known as kinky back syndrome is a deformity of the free sixth thoracic vertebra including enlargement and rotation resulting in posterior paralysis in broiler chicken. Genotype, feeding regimes and environment are involved in occurrence of this congenital anomaly. Spondylolisthesis may result in or happen simultaneously with two other major axial skeleton pathologies including spondylosis and spondylitis as a result of occurrence of degenerative necrobiotic lesions and inflammation of the vertebrae, respectively. This report deals with a male broiler chicken with posterior paralysis in the second week of rearing. After euthanasia, the specimen was evaluated at macroscopic and microscopic levels. Macroscopic findings showed the unilateral enlargement of body and transverse process of sixth thoracic vertebra and downward rotation of the body. The histopathological studies revealed the focal chondronecrosis and degenerative changes in articular facets and cranial process of the vertebra. In conclusion, a diagnosis of spondylolisthesis followed by spondylosis was made based on macroscopic and histopathological findings that to the authors' best knowledge, is the first report in a broiler farm in Iran.

Effect of dietary supplementation of nanocurcumin on oxidant stability of broiler chicken breast meat infected with Eimeria species.

Poultry meat is very susceptible to oxidation because of the high concentration of polyunsaturated fatty acids, which negatively affects the quality and nutritional values of chicken meat. Coccidiosis is the most common parasitic disease of poultry. Intending to limit anti-parasites usage in poultry feed and also because of the concerns about antibiotic resistance and residues in poultry products, there is a need for research to discover natural alternatives. The effect of nanocurcumin on antioxidant profile (carotenoid and vitamin E contents, lipid oxidation and antioxidant capacity) and pH of broiler chicken breast meat infected with Eimeria species was investigated. Fifty, one-day-old male Ross 308 broiler chickens were assigned to five treatments including non-infected and non-medicated control (NNC), infected non-supplemented control (INC), infected and medicated with nanocurcumin 300 mg kg-1 feed (NCRM1), infected and medicated with nanocurcumin 400 mg kg-1 feed (NCRM2) and infected and antibiotic medicated group. Infection with Eimeria acervulina, E. maxima, and E. tenella decreased vitamin E and carotenoid contents of chicken breast meat significantly. The NCRM2 had significantly enhanced carotenoid and vitamin E levels in chicken breast meat, so  there was no significant difference between NCRM2 and NNC group. No significant change was observed in pH value among groups. Malondialdehyde value of breast meat was significantly lower in NCRM1 and NCRM2 than the INC group. The NCRM2 and NCRM1 showed the best antioxidant capacity even better than NNC. In conclusion, nanocurcumin could be a potential feed additive that can increase oxidant stability of broiler chicken breast meat.

Isolation and characterization of mycoflora of chicken hatcheries in Mazandaran province, north of Iran.

Fungal infections cause significant economic losses in the poultry industry either due to their direct infectious nature or due to mycotoxins production. Hatchery contamination with fungi can threaten chicken health. In this regard, geographical and seasonal distributions of airborne fungal contamination of 25 hatcheries in Mazandaran province, northern Iran, were investigated using an open plate method. The results of this study showed that hatcheries have various fungal contaminations, among which the most common were respectively Cladosporium (31.07%), Penicillium (24.00%), Aspergillus (20.63%), sterile hyphae (14.70%) and Alternaria (6.20%) from different regions. The results revealed that the highest level of fungal isolation was in spring and autumn. This study also showed that the concentration of fungal air spora in forest and seaside locations was significantly greater than mountainous ones. In spite of the regular disinfection in commercial hatcheries, fungal contamination was found in different parts.

Safety assessment of rice bran oil in a chicken embryo model.

OBJECTIVE: Rice Bran Oil (RBO) is extracted from the outer layer of rice. Little information is available regarding its safety. The present study was conducted to assess its safety in chicken embryo model. MATERIALS AND METHODS: RBO was injected on day 4 of incubation of chickens. The tissues and serum samples were collected. Oxidative stress parameters in the liver, kidney and brain and biochemical parameters of serum were measured. The deformities were also investigated. RESULTS: The changes in the liver enzymes activity were not statistically significant. There was significant decrease and increase in lipid peroxidation and glutathione level, respectively. It is suggested that RBO is a natural antioxidant source. Low-density lipoprotein cholesterol (LDL) also decreased. No abnormal findings were observed in the chickens. CONCLUSION: No toxic effect was observed following RBO administration in chicken embryos. This study showed that RBO is not a safety concern.

Genetic Characterization of Campylobacter Jejuni and C. coli Isolated From Broilers Using flaA PCR-Restriction Fragment Length Polymorphism Method in Shiraz, Southern Iran.

BACKGROUND: Thermophilic campylobacters, particularly Campylobacter jejuni and C. coli are the main agents of human campylobacteriosis. Campylobacter contaminated chicken products is the most important source of foodborne gastroenteritis. Evaluation of genetic diversity among Campylobacter population is critical for understanding the epidemiology of this bacterium and developing effective control strategies against Campylobacter infections and other related disorders. OBJECTIVES: The aim of this study was to investigate the polymorphism of thermophilic Campylobacter isolated from broiler fecal samples in Shiraz, southern Iran. MATERIALS AND METHODS: Ninety Campylobacter isolates were recovered from broiler feces using enrichment process followed by cultivation method. The isolates were species typing on the basis of polymerase chain reaction (PCR) detection of 16SrRNA and multiplex PCR for determining two thermophilic species. To evaluate strain diversity of thermophilic Campylobacter isolates, flaA PCR-Restriction Fragment Length Polymorphism (RFLP) was performed using DdeI restriction enzyme. RESULTS: All 90 Campylobacter isolates confirmed by m-PCR were successfully typed using flaA-PCR-RFLP. Eleven different types were defined according to flaA-typing method and the RFLP patterns were located at three separate clusters in RFLP image analysis dendrogram. CONCLUSIONS: Campylobacter jejuni isolates significantly showed more variety than C. coli isolates. A relatively low genetic diversity existed among C. jejuni and C. coli isolated from broilers in Shiraz, southern Iran. In our knowledge, this was the first report of genetic diversity among broiler originated human pathogen thermophilic campylobacters in Shiraz, southern Iran.

Prevalence and risk factors for subclinical coccidiosis in broiler chicken farms in Mazandaran province, Iran.

Coccidiosis is a disease of almost universal importance in Poultry production. The subclinical form of coccidiosis has most significant economic impact due to impaired growth rate and feed conversion. Some factors such as: age, size of flock, season, etc., may effect on severity of this disease. In this study, the relationships between some major risk factors and prevalence of subclinical coccidiosis were investigated. This study was done in 120 broiler farms in five different cities of Mazandaran province, north of Iran. Five chicks (3-8 weeks of ages) were taken randomly from every 120 farms and post-mortem and parasitological examinations were performed. Five Eimeria spp. were recognized: Eimeria tenella, Eimeria maxima, Eimeria acervulina, Eimeria brunetti, and Eimeria necatrix. The prevalence rate of subclinical coccidiosis among them is 75% (90 farms out of 120). E. acervulina was the most prevalent species (65.5%) followed by E. maxima (17.7%), E. tenella (15.5%), E. brunetti (10%), and E. necatrix (5.5%). According to what the results approve, the occurrence of subclinical coccidiosis is significantly related to the age and size of flock, whereas the other factors such as the season of year, industrial strains, chicken's keeping system, and anticoccidial drugs do not affect this phenomenon remarkably.