Bandgap tailoring and enhancing the aromatization in cysteine-based carbon dots.

Cysteine, as a non-aromatic precursor, was used to produce Nitrogen (N) and Sulfur (S) sources for preparing N, S-doped carbon dots (CDs) with tunable luminescence emission. Despite the tremendous investigations, the photoluminescence (PL) mechanism of CDs is still unclear due to its complex core-shell structure, variety of surface functional groups, and structure dependency. This study focuses on controlling aromatization and graphitization processes during the hydrothermal synthesis on CDs by using Citric Acid (CA) and Ammonium persulfate. Detailed characterizations by FTIR spectroscopy, XPS, and HR-TEM are provided to suggest both chemical and bandgap structures. Results reveal that the red-shift of PL occurred due to the graphitization and increasing content of graphitic nitrogen in the core, as well as the Pyridinic and Amine groups creating sub-bands on the surface. These findings resolve the controversy on the PL mechanism of Cysteine-based CDs and provide a general guide for increasing the aromatization and graphitization degree from non-aromatic precursors which clarify the mechanism exploration and structural analysis of other types of CDs.

Evaluation of viral load and expression level of apoptotic genes in selected tissues of two hybrids of commercial broiler chickens challenged with infectious bronchitis virus: a comparative study.

Background: Infectious bronchitis virus (IBV) causes severe economic losses worldwide. IBV has a broad tissue distribution with different viral loads in different tissues. Additionally, IBV can induce apoptosis in infected cells. Aims: The present study aimed to evaluate the role of the genetic background of chickens in viral load and the expression level of apoptotic genes in different tissues of two hybrids of commercial broiler chickens (Ross 308 and Cobb 500) challenged with IBV. Methods: Chickens at 21 days of age were nasally challenged with 200 µL of allantoic fluid containing 104 EID50/ml of Iranian variant-2-like IBV (IS/1494). The expression level of apoptotic genes (Fas, FasL, Bax, and Bcl-2) in the tracheal and renal tissues and the amount of viral load in the tracheal, renal, and cloacal swab samples were investigated two, five, and seven days after IBV infection by RT-qPCR assay. Results: The amount of viral load and apoptotic the expression level of apoptotic genes in the tracheal (two and five days after infection) and renal samples (seven days after infection) were significantly higher in the Ross challenged group than in the Cobb challenged group.Furthermore, no difference was observed in the cloaca viral load on sampling days. Conclusion: To our knowledge, this is the first report that evaluated the role of the chickens' genetic background in the amount of viral load and the expression level of apoptotic genes against IBV. Further studies are needed to investigate the pathogenic characteristics of IBV in Ross 308 and Cobb 500 chickens.

Report of a new meq gene size: The first study on genetic characterisation of Marek's disease viruses circulating in Iranian commercial layer and backyard chicken.

1. In recent months, several outbreaks with clinical signs of MDV-1 were reported in Iranian parent and laying hen farms, in addition to backyard chickens. Several meq gene sequences from these outbreaks were amplified and molecularly characterised.2. The meq protein sequences revealed three different sizes, namely the standard 339 aa, a shorter form of 338 aa lacking a proline residue at position 191, and a very short (vs) size of 265 aa. Based on sequence and size, the 265 aa meq has never been reported from international research groups before. The protein has only one PPPP repeat motif suggesting it belongs to a highly virulent strain.3. The standard meq sequences showed 100% BLAST identity to the vv+ isolate Polen5. However, the 338 aa form clustered to the clade usually reported from North America.4. This is the first report on genetic analysis of MDV-1 from Iran, but further study is required to obtain a better picture of the diversity and prevalence of different MDV-1 strains circulating in the country's farms, backyard poultry and other bird species.

Controlled temperature-mediated curcumin release from magneto-thermal nanocarriers to kill bone tumors.

Systemic chemotherapy has lost its position to treat cancer over the past years mainly due to drug resistance, side effects, and limited survival ratio. Among a plethora of local drug delivery systems to solve this issue, the combinatorial strategy of chemo-hyperthermia has recently received attention. Herein we developed a magneto-thermal nanocarrier consisted of superparamagnetic iron oxide nanoparticles (SPIONs) coated by a blend formulation of a three-block copolymer Pluronic F127 and F68 on the oleic acid (OA) in which Curcumin as a natural and chemical anti-cancer agent was loaded. The subsequent nanocarrier SPION@OA-F127/F68-Cur was designed with a controlled gelation temperature of the shell, which could consequently control the release of curcumin. The release was systematically studied as a function of temperature and pH, via response surface methodology (RSM). The bone tumor killing efficacy of the released curcumin from the carrier in combination with the hyperthermia was studied on MG-63 osteosarcoma cells through Alamar blue assay, live-dead staining and apoptosis caspase 3/7 activation kit. It was found that the shrinkage of the F127/F68 layer stimulated by elevated temperature in an alternative magnetic field caused the curcumin release. Although the maximum release concentration and cell death took place at 45 °C, treatment at 41 °C was chosen as the optimum condition due to considerable cell apoptosis and lower side effects of mild hyperthermia. The cell metabolic activity results confirmed the synergistic effects of curcumin and hyperthermia in killing MG-63 osteosarcoma cells.

Lesion Border Detection of Skin Cancer Images Using Deep Fully Convolutional Neural Network with Customized Weights.

Deep learning techniques have been widely employed in semantic segmentation problems, especially in medical image analysis, for understanding image patterns. Skin cancer is a life-threatening problem, whereas timely detection can prevent and reduce the mortality rate. The aim is to segment the lesion area from the skin cancer image to help experts in the process of deeply understanding tissues and cancer cells' formation. Thus, we proposed an improved fully convolutional neural network (FCNN) architecture for lesion segmentation in dermoscopic skin cancer images. The FCNN network consists of multiple feature extraction layers forming a deep framework to obtain a larger vision for generating pixel labels. The novelty of the network lies in the way layers are stacked and the generation of customized weights in each convolutional layer to produce a full resolution feature map. The proposed model was compared with the top four winners of the International Skin Imaging Collaboration (ISIC) challenge using evaluation metrics such as accuracy, Jaccard index, and dice co-efficient. It outperformed the given state-of-the-art methods with higher values of the accuracy and Jaccard index.

Molecular characterization of circulating avian metapneumovirus, subgroup B, in broiler chickens, Iran, 2016-2018.

BACKGROUND: Avian metapneumovirus (aMPV) infection has significant economic impacts on the poultry industry all around the world. AIMS: The aim of this study is molecular investigations of different types of aMPV in broiler farms in different provinces of Iran from 2016 to 2018. METHODS: Tracheal and oropharyngeal swabs were collected from two hundred broiler chickens with respiratory signs in ten provinces of Iran, including Kurdistan, West Azerbaijan, Semnan, Esfahan, Sistan and Baluchistan, Qazvin, Khuzestan, Fars, Gilan, and Khorasan Razavi from February 2016 to December 2018. After RNA extraction, the presence of aMPV was confirmed using N gene special primers. Then, subtype-specific primers were utilized to differentiate the specific subtype. All positive samples were sequenced. RESULTS: As a general trend, the percentage of aMPV positive chickens increased gradually over time. All samples were clustered together and placed in the subtype B aMPV group. Although 2 samples from 2016 and 2 samples from 2018 were placed in a separate branch, most of the current study samples of 2016, 2017, and 2018 revealed six segregated sub-branches, and they were placed close to other isolates of 2011 and 2013 from Iran. CONCLUSION: The current field study indicated the presence of aMPV in a considerable number of areas in Iran. Thus, the role of this virus in broiler respiratory complex should not be neglected.

Molecular detection of fowl adenovirus 7 from slaughtered broiler chickens in Iran: the first report.

BACKGROUND: Fowl adenoviruses (FAdVs) are responsible for a variety of clinical symptoms, with an increasing significance in the poultry industry throughout the world. Typical diseases caused by FAdVs include inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HHS), gizzard erosion (GE), respiratory disease, and hemorrhage in muscles and organs. AIMS: During 2020, broiler chickens from the north of Iran showed ecchymotic and petechial hemorrhages in thigh and breast muscles at the slaughterhouse. Hemorrhages were observed in 10% to 60% (with an average of 20-30%) of chicks per flock. To find out the etiology of these lesions, the present study was conducted. METHODS: Different environmental factors were investigated, and FAdV, infectious bursal disease virus (IBDV), and chicken infectious anemia virus (CIAV) were detected using molecular assays. RESULTS: Among the viruses tested, FAdV was detected by polymerase chain reaction (PCR), and sequence analysis clustered the virus into species E, serotype 7. CONCLUSION: This is the first report on FAdV-7 existence among poultry in Iran. Effective screening of the chicks at slaughtering age should be performed from the whole country.

Hemagglutinin-neuraminidase Sequence and Phylogenetic Analysis of Two Newcastle Disease Virus Isolated from Chickens in Iran.

Newcastle disease is a highly contagious viral infection affecting many species of birds that can spread fast between poultry houses and cause a heavy economic burden on the poultry industry all around the world. Fusion and hemagglutinin-neuraminidase (HN) protein are important in the pathogenesis of the Newcastle disease virus (NDV). The HN protein is a critical viral protein with multiple functions and plays a key role in the formation of the virulence of NDV. Head of HN protein is responsible for receptor binding, neuraminidase activity. This study aimed to investigate the sequence homology of hemagglutinin-neuraminidase of two NDV isolates sampled from infected farms in Iran. The samples were collected from flocks that had been vaccinated by both types of live and killed vaccines for NDV. After isolation of NDV, the viruses were subjected to the polymerase chain reaction (PCR) amplification using two pairs of specific primers designed for the HN gene to amplify the complete HN gene (1730bp). Afterward, the PCR products were sequenced and analyzed by phylogenetic tree construction software. Based on the analysis, substantial sequence homology among Iranian isolates is within the range of 97.1-100%. Moreover, the sequence homology searching revealed a level of similarity between HN sequences of Iranian isolates and the HN sequences from other countries, particularly Asian ones. For instance, a high homology ratio (95.34%) was found between Iranian isolates and the sequences registered on online molecular databases from China. Based on phylogenetic analysis, the NDV isolates belong to the VIId genotype. Finally, it can be concluded that monitoring the circulation of NDVs among poultry and other birds can help to obtain an insight into the evolution of NDVs and control of panzootic viruses in the future.

Clinical description of the broad range of neurological presentations of COVID-19: A retrospective case series.

BACKGROUND: Neurological disorders associated with SARS-CoV-2 infection represent a clinical challenge because they encompass a broad neurological spectrum and may occur before the diagnosis of COVID-19. METHODS: In this monocentric retrospective case series, medical records from patients with acute neurological disorders associated with SARS-CoV-2 infection from medicine departments of an academic center in Paris area were collected between March 15th and May 15th 2020. Diagnosis of SARS-CoV-2 was ascertained through specific RT-PCR in nasopharyngeal swabs or based on circulating serum IgG antibodies. RESULTS: Twenty-six patients diagnosed with SARS-CoV-2 infection presented with neurological disorders: encephalitis (N=8), encephalopathy (N=6), cerebrovascular events (ischemic strokes N=4 and vein thromboses N=2), other central nervous system (CNS) disorders (N=4), and Guillain-Barré syndrome (N=2). The diagnosis of SARS-CoV-2 was delayed on average 1.6 days after the onset of neurological disorder, especially in case of encephalitis 3.9 days, encephalopathy 1.0 day, and cerebrovascular event 2.7 days. CONCLUSIONS: Our study confirms that COVID-19 can yield a broad spectrum of neurological disorders. Because neurological presentations of COVID-19 often occur a few days before the diagnosis of SARS-COV-2 infection, clinicians should take preventive measures such as patient isolation and masks for any new admission to avoid nosocomial infections. Anti-SARS-CoV2 antibody detection in RT-PCR SARS CoV-2 negative suspected cases is useful to confirm a posteriori the diagnosis of atypical COVID-19 presentations.

laying Farm: Up to Date Data on a Fowlpox Outbreak in Phylogenetic Analysis in Iran, 2018.

Fowlpox is an economically significant viral disease in poultry, characterized by two forms of clinical signs, including cutaneous and diphtheritic lesions. This infection can have several adverse effects on flock performance, such as a reduction in egg production and growth and an increase in mortality. In winter 2018, an infection suspected to fowlpox was reported from a Hy-line W-36 laying farm in Isfahan province, Iran. The birds were 38 weeks of age and showed obvious diphtheritic signs in mucous membranes with increased mortality and reduced egg production. In total, 20 samples were collected from diphtheritic lesions (Trachea and Esophagus) of infected birds. The Polymerase Chain Reaction method was used to amplify a 578 bp fragment of the poxvirus 4b core protein gene. Phylogenetic relationships of avian poxviruses are usually analyzed using the 4b core protein-coding gene sequences with molecular weights of 75.2 kDa. The major elements had the fowlpox genome, and sequencing was performed for one isolate as representative. The nucleotide sequence result showed that this isolate (FP\UT-POX-2018) had a similarity rate of 99.53% with the previous Iranian fowlpox isolate (FP\GHPCRLAB.3) sequenced in the GenBank.Moreover, there was a 100% similarity among the current isolate nucleotide sequence, FP/NobilisVarioleW, and FP/FPV-VR250. The derived phylogenetic tree showed that these isolates were clustered in A1 subclades. Therefore, Iranian isolates of fowlpox virus have remained in the same subclade of phylogenetic classification (subclade A1), and they show high genomic similarity with previous isolates of Iran. Veterinarians and farmers must not underestimate fowlpox. However, they should consider the importance of vaccination against this disease like any other disease care.

Molecular characterization and the first full sequencing genome of chicken infectious anemia virus (CIAV) in Iran.

BACKGROUND: The chicken infectious anemia virus (CIAV) is an important pathogen that causes severe immunosuppression in young chickens. AIMS: The study aims to characterize the genotype and full-length sequencing of CIAV strains in Iran. METHODS: First, the collected thymus samples were investigated by conventional PCR for CIAV detection. Second, one of the CIAV positive samples (UT-Zahraee) was chosen for full genome sequencing. RESULTS: Throughout 2017, we detected 13 CIAVs isolated from 40 broiler flocks of different provinces of Iran. A comparison of the complete sequences of the genome and homologies of the nucleotides revealed that UT-Zahraee had a high similarity with American and Egyptian CIAV isolates. Moreover, VP1 sequence analysis showed that UT-Zahraee shared high homology with previously reported Iranian CIAV strains, Chinese, and Egyptian isolates. CONCLUSION: This study is the first report of full genome sequencing of CIAV strain from Iran. It will be beneficial to understand better the epidemiology and molecular characteristics of CIAV circulating in Iran.

Stroke symptoms impact on mental and physical health: A Lebanese population based study.

BACKGROUND/OBJECTIVE: Stroke symptoms in the absence of diagnosed stroke are common worldwide and associated with stroke risk factors and great impact on the physical and mental health functioning. The aim of this study was to assess, at the national level, the association of stroke symptoms with mental and physical health. METHODS: Quality of life was assessed using physical and mental component summary scores (PCS and MCS) of the Short Form 12v2 Health Survey in the Lebanese population. We assessed the differences in the mean PCS and MCS scores among asymptomatic individuals with no stroke/transient ischemic attack (TIA) history (n=1167), symptomatic individuals with no stroke/TIA history (n=125) and those with stroke/TIA history (n=46). Psychometric properties of the Lebanese version of the SF- 12v2 were evaluated using principal component analysis. RESULTS: Symptomatic individuals had an average PCS scores of 2.31 (95%CI: 0.75-3.88) points lower and those with stroke/TIA history had 3.26 (95%CI: 1.01-5.51) points lower when compared with asymptomatic individuals with no stroke/TIA history. Similarly, MCS scores for symptomatic individuals were 2.58 (95%CI: 1.02-4.13) points lower and those with stroke/TIA history had 3.28 (95%CI: 1.06-5.50) points lower than asymptomatic individuals. CONCLUSION: Physical and mental health functioning declined among symptomatic individuals and those with stroke/TIA history. Thus, frequent monitoring for the early detection of stroke symptoms may be recommended.

The emergence of Q1 genotype of avian infectious bronchitis virus in Iran, 2019: the first report.

BACKGROUND: Avian infectious bronchitis (IB) is an infectious viral disease of chickens. The effective protection of chickens against many different infectious bronchitis virus (IBV) variants is not achieved unless the circulating genotypes in the region are identified and the cross-protection of the potential of vaccines in use is assessed. AIMS: In a monitoring program of IBVs, a new genotype was identified in the north of Iran, 2019. This work was conducted to isolate and characterize this new IBV genotype. METHODS: Tracheal tissues were collected from chickens showing signs of respiratory involvement. Specimens were homogenized and inoculated to the allantoic fluid of embryonated specific pathogen-free (SPF) eggs. Infectious bronchitis virus was detected using real time-polymerase chain reaction (RT-PCR). The hypervariable region of the IBV S1 gene was amplified for sequencing. RESULTS: Positive samples were phylogenetically analyzed, and both positive isolates were clustered with Q1 IBV strains. CONCLUSION: This is the first report of the Q1 outbreak in Iran. More investigations are needed to find the role of Q1 IBV in the respiratory disease complex of chickens.

Comparison of autogenous and commercial H9N2 avian influenza vaccines in a challenge with recent dominant virus.

BACKGROUND: Avian influenza (AI) caused by AI virus subtype H9N2 is a prevalent viral disease with enormous economic losses in poultry farms through significant respiratory and gastrointestinal manifestations. The degree of protection obtained from a vaccine strongly depends on the level of antigenic similarity between challenge and vaccine virus. AIMS: The study aimed at investigating the possible effects of continuous antigenic changes occurring in circulating Iranian viruses since 1998 on the commercial vaccines outcome by using vaccine seeds from earlier outbreaks for inhibiting viral replication in target organs of broilers challenged with the recent isolate. METHODS: Ninety broilers at one day of age were randomly allocated into 5 groups and vaccinated with autogenous or commercial vaccines (A or B). Two remaining groups consisted of challenged without vaccination and intact birds. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed on the trachea and faecal samples of challenged chickens with recent H9N2 virus to determine viral load. Moreover, humoral antibodies titers were evaluated by hemagglutination inhibition (HI) assay. RESULTS: There was no significant difference in H9N2 viral load in the trachea among vaccinated groups on 5 days post challenge (DPC), but on 15 DPC, the autogenous vaccine significantly lowered viral load compared to commercial vaccines (P≤0.05). No significant differences in faecal swab's viral load was observed between autogenous and commercial vaccine A, and both of them significantly inhibited viral load compared to unvaccinated group (P≤0.05). In addition, the autogenous vaccine elicited the highest HI titer. CONCLUSION: Inactivated vaccines that use isolates from previous outbreaks are no longer able to induce proper immunity against recent H9N2 viruses. It seems the time to change vaccine strains to more recent isolates that have better antigenic similarity with current circulating H9N2 viruses in the region has come.

Probing Flow-Induced Biomolecular Interactions With Micro-Extensional Rheology: Tau Protein Aggregation.

Biomolecules in solutions subjected to extensional strain can form aggregates, which may be important for our understanding of pathologies involving insoluble protein structures where mechanical forces are thought to be causative (e.g., tau fibers in chronic traumatic encephalopathy (CTE)). To examine the behavior of biomolecules in solution under mechanical strains requires applying rheological methods, often to very small sample volumes. There were two primary objectives in this investigation: (1) To probe flow-induced aggregation of proteins in microliter-sized samples and (2) To test the hypothesis that tau protein aggregates under extensional flow. Tau protein (isoform:3R 0 N; 36.7 kDa) was divided into 10 µl droplets and subjected to extensional strain in a modified tensiometer. Sixteen independent tests were performed where one test on a single droplet comprised three extensional events. To assess the rheological performance of the fluid/tau mixture, the diameter of the filament that formed during extension was tracked as function of time and analyzed for signs of aggregation (i.e., increased relaxation time). The results were compared to two molecules of similar and greater size (Polyethylene Oxide: PEO35, 35 kDa and PEO100, 100 kDa). Analysis showed that the tau protein solution and PEO35 are likely to have formed aggregates, albeit at relatively high extensional strain rates (∼10 kHz). The investigation demonstrates an extensional rheological method capable of determining the properties of protein solutions in µl volumes and that tau protein can aggregate when exposed to a single extensional strain with potentially significant biological implications.

Genotyping of avian infectious bronchitis virus in Afghanistan (2016-2017): the first report.

BACKGROUND: Avian infectious bronchitis (IB) is a highly contagious viral disease which affects the poultry industry. The virus exists in a wide variety of genotypes, and phylogenetic analysis has been used to classify infectious bronchitis virus (IBV) strains. AIMS: The object of the study is a molecular characterization of circulating IBV in Afghanistan as a first study. METHODS: The tracheal tissue specimens from 100 different commercial broiler flocks with respiratory distress in Afghanistan were collected during 2016-2017. After real-time reverse transcriptase-polymerase chain reaction (RRT-PCR), IBV-positive samples were further characterized. A 390 bp hypervariable spike glycoprotein gene segment was amplified using Nested PCR, sequenced, and analyzed. RESULTS: The results of real-time RT-PCR showed that 45/100 of the mentioned flocks were IBV positive. Phylogenetic analysis of all positive samples revealed that IBV strains were clustered into two distinct genotypes: LX4 (GI-19) (9/45) and IS-1494 like (GI-23) (34/45). Also, 2 of the 45 samples remained uncharacterized. CONCLUSION: It is the first study focusing on the molecular epidemiology of IBV in Afghanistan, extending our understanding of IB in the region. These results showed the high rate of IB infection in Afghanistan broiler farms and confirm the continuing monitoring of IBVs to modify the vaccination program.

Validation of distal radius failure load predictions by homogenized- and micro-finite element analyses based on second-generation high-resolution peripheral quantitative CT images.

This study developed a well-standardized and reproducible approach for micro-finite element (mFE) and homogenized-FE (hFE) analyses that can accurately predict the distal radius failure load using either mFE or hFE models when using the approaches and parameters developed in this study. INTRODUCTION: Micro-FE analyses based on high-resolution peripheral quantitative CT (HR-pQCT) images are frequently used to predict distal radius failure load. With the introduction of a second-generation HR-pQCT device, however, the default modelling approach no longer provides accurate results. The aim of this study was to develop a well-standardized and reproducible approach for mFE and hFE analyses that can provide precise and accurate results for distal radius failure load predictions based on second-generation HR-pQCT images. METHODS: Second-generation HR-pQCT was used to scan the distal 20-mm section of 22 cadaver radii. The sections were excised and mechanically tested afterwards. For these sections, mFE and hFE models were made that were used to identify required material parameters by comparing predicted and measured results. Using these parameters, the models were cropped to represent the 10-mm region recommended for clinical studies to test their performance for failure load prediction. RESULTS: After identification of material parameters, the measured failure load of the 20-mm segments was in good agreement with the results of mFE models (R2 = 0.969, slope = 1.035) and hFE models (R2 = 0.966, slope = 0.890). When the models were restricted to the clinical region, mFE still accurately predicted the measured failure load (R2 = 0.955, slope = 1.021), while hFE predictions were precise but tended to overpredict the failure load (R2 = 0.952, slope = 0.780). CONCLUSIONS: It was concluded that it is possible to accurately predict the distal radius failure load using either mFE or hFE models when using the approaches and parameters developed in this study.

The efficacy and safety of other cryotherapy compounds for the treatment of genital warts: a randomized controlled trial.

BACKGROUND: Cryotherapy using Wartner compound that contains a mixture of dimethyl ether (75%) and propane (25%) has been recently reported as an effective treatment for warts. The present study aimed to evaluate the safety and efficacy of Wartner in male patients with genital warts. METHODS: A Phase II parallel-randomized clinical trial was performed on 16 Iranian men affected by genital warts who were referred to a dermatology clinic at Tehran University of Medical Sciences. Two genital warts of each patient were selected and randomly assigned to receive either Wartner (intervention) or liquid nitrogen (control). RESULTS: Two weeks after the treatment, the sizes of the lesions in control and intervention groups decreased by 17.87 ± 2.14 mm2 and 15.81 ± 1.80 mm2, respectively (p = .299). Fourteen days after a single session of treatment, 81% of lesions in the control group and 50% in the Wartner group were completely eradicated, however, the difference was not statistically significant (p = .063). CONCLUSIONS: The Wartner compound is as effective as the conventional cryotherapy method for treating genital warts. It is particularly valuable when there are contraindications or no access to common treatment options.

In vitro removal of polycyclic aromatic hydrocarbons by lactic acid bacteria.

AIMS: The current study aimed to investigate the ability of lactic acid bacteria (LABs) in removing four polycyclic aromatic hydrocarbons (PAHs) namely, benzo(a)pyrene (BaP), benz(a)anthracene (BaA), chrysene (Chr) and benzo(b)fluoranthene (BbF) from contaminated phosphate buffer saline (PBS). METHOD AND RESULTS: The effect of initial PAH concentrations (5, 10, 15, 20 µg ml-1 ), bacterial population (107 , 108 , 109 , 1010 CFU per ml) and pH (3, 5, 7) was studied to evaluate bacterial binding ability. All the tested bacteria could remove BaA, Chr, BbF and BaP from phosphate buffer solution and in almost all assays, removing of PAHs was as follows: BaP>Chr>BaA>BaF. Bifidobacterium lactis BB-12 had the lowest binding rate for all four PAHs, while the highest binding ability was related to Lactobacillus acidophilus LA-5. Moreover, cell viability was not required for the binding ability and even acid-treated, heat-treated and ultrasonic-treated bacterial cells showed more binding ability. The results showed that the bacteria-PAH complex was irreversible after washing with PBS. CONCLUSIONS: The removal of PAHs was significantly related to pH of media, strains of bacteria, type and concentration of PAHs SIGNIFICANCE AND IMPACT OF THE STUDY: This study has been focused on the reduction of polycyclic aromatic hydrocarbons using LABs and probiotics. Our results showed that not only live strains but also inactivated tested strains are able to remove PAHs from aqueous media, presenting new methods to diminish the amount of these contaminants in foods. Furthermore, the results of this study can be used in future research on evaluating the effects of oral administration of probiotic supplements and even dead probiotic strains on reducing PAHs in humans.

Importance of Listeria monocytogenes in food safety: a review of its prevalence, detection, and antibiotic resistance.

Listeria monocytogenes, as a foodborne pathogenic bacterium, is considered as major causative agent responsible for serious diseases in both humans and animals. Milk and dairy products are among the main sources of energy supply in the human, therefore contamination of these products with Listeria spp., especially L. monocytogenes, could lead to life threatening infections in a large population of people. Rapid and accurate detection of L. monocytogenes in milk and dairy products, vegetables, meat, poultry, and seafood products is needed to prevent its dissemination through the food chain. Upon contamination of food materials with this pathogen, increase in its antibiotic resistance rate can occur after exposure to preservatives, antibiotics, and stress conditions, which has now become another major public health concern emphasizing the need for special attention on its control along the food chain and management of the disease in the patients. This review provides an overview of researches with respect to the prevalence of Listeria spp., especially L. monocytogenes, in milk and dairy products, methods of their detection and typing, and current status of resistance rates to the antibiotics used for treatment of listeriosis.