Molecular evaluation of sheep and goats isolates of Pasteurella multocida and their antibiotic resistance

Pasteurella multocida exists as a commensal in the upper respiratory tracts of livestock, and poultry, and causes a wide variety of diseases in humans and animals. This study aimed to investigate the incidence of P. multocida by bacteriological and molecular characterization in sheep and goats and screening the existence of capsule-specific genes and their antibiotic resistance pattern. Totally, 1650 nasopharyngeal swabs were collected from apparently healthy sheep and goats and 460 lung tissues were collected from slaughtered animals in Fars province, Iran. All samples were cultured and suspected colonies were examined by biochemical tests, antimicrobial assay and polymerase chain reaction (PCR). Among 165 P. multocida (104 sheep and 61 goats) isolates, the capA, capD, and capB genes were amplified in 98, 48, and 12 isolates, respectively. The occurrence of four virulence-associated genes of P. multocida isolates were determined by PCR. Most isolates harbored the toxA (79.40%) and hgbB genes (70.90%) and 59.40% of isolates had the pfhA gene. Almost half of the isolates (46.10%) contained the tbpA gene. According to the current study, P. multocida capsular type A had the most frequency followed by type D. In addition, the high frequency of tbpA, pfhA, toxA, and hgbB genes revealed that these genes are possibly important in the pathogenesis of P. multocida. Oxytetracycline, enrofloxacin, florfenicol, and tilmicosin were the most effective drugs.

Generation and characterization of two immortalized dermal fibroblast cell lines from the spiny mouse (Acomys)

The spiny mouse (Acomys) is gaining popularity as a research organism due to its phenomenal regenerative capabilities. Acomys recovers from injuries to several organs without fibrosis. For example, Acomys heals full thickness skin injuries with rapid re-epithelialization of the wound and regeneration of hair follicles, sebaceous glands, erector pili muscles, adipocytes, and dermis without scarring. Understanding mechanisms of Acomys regeneration may uncover potential therapeutics for wound healing in humans. However, access to Acomys colonies is limited and primary fibroblasts can only be maintained in culture for a limited time. To address these obstacles, we generated immortalized Acomys dermal fibroblast cell lines using two methods: transfection with the SV40 large T antigen and spontaneous immortalization. The two cell lines (AcoSV40 and AcoSI-1) maintained the morphological and functional characteristics of primary Acomys fibroblasts, including maintenance of key fibroblast markers and ECM deposition. The availability of these cells will lower the barrier to working with Acomys as a model research organism, increasing the pace at which new discoveries to promote regeneration in humans can be made.

Nanoscale vibration could promote tenogenic differentiation of umbilical cord mesenchymal stem cells

Regulation of mesenchymal stem cell (MSC) fate for targeted cell therapy applications has been a subject of interest, particularly for tissues such as tendons that possess a marginal regenerative capacity. Control of MSCs' fate into the tendon-specific lineage has mainly been achieved by implementation of chemical growth factors. Mechanical stimuli or 3-dimensional (D) scaffolds have been used as an additional tool for the differentiation of MSCs into tenocytes, but oftentimes, they require a sophisticated bioreactor or a complex scaffold fabrication technique which reduces the feasibility of the proposed method to be used in practice. Here, we used nanovibration to induce the differentiation of MSCs toward the tenogenic fate solely by the use of nanovibration and without the need for growth factors or complex scaffolds. MSCs were cultured on 2D cell culture dishes that were connected to piezo ceramic arrays to apply nanovibration (30-80 nm and 1 kHz frequency) over 7 and 14 d. We observed that nanovibration resulted in significant overexpression of tendon-related markers in both gene expression and protein expression levels, while there was no significant differentiation into adipose and cartilage lineages. These findings could be of assistance in the mechanoregulation of MSCs for stem cell engineering and regenerative medicine applications.

Bioinformatics design of recombinant chimeric protein containing SipD and LptD immunogens and evaluation of its immunogenicity against Salmonella Typhimurium

The growing emergence of resistant bacteria is the current global concern for the humans and animals. Vaccination could be the desirable method to preventing such infectious diseases. Safe and effective vaccines are urgently needed to manage and prevent Salmonella contamination. Subunit vaccines are safe approaches for the protection against Salmonella spp. The bioinformatics methods were performed to determine the gene structure. Gene cassette (rLPSI) was ordered in pET28a (+), and cloned into E.coli BL21 (DE3), and the recombinant protein was expressed using IPTG (1 mM). Mice were immunized by subcutaneous administration of recombinant protein. Then, the mice were challenged by oral administration of 100LD₅₀ of live S. Typhimurium. The Codon adaptation index of the chimeric gene was multiplied by 0.92. Validation results showed that >90% of residues lie in the desired or extra allowed area of the Ramachandran plot. The recombinant protein (65.9 kDa) was expressed in E.coli. Antibody titers in vaccinated mice were significantly different from those in the control groups. Recombinant protein immunization of the mice provided 90% and 70% protection against 10LD₅₀ and 100LD₅₀ of S. Typhimurium, respectively. In general, the results showed the high efficiency of rLPSI chimeric protein as a protective antigen against S. Typhimurium infection. The rLPSI chimeric protein could be an effective recombinant vaccine candidate against S. Typhimurium infection, but more research is needed.

Genotypic evaluation of Pasteurella multocida isolated from cattle and sheep by pulsed-field gel electrophoresis

Pasteurella multocida a Gram-negative bacterium exists as a commensal in the upper respiratory tracts of livestock, and poultry. It is causative agent of a range of diseases in mammals and birds including fowl cholera in poultry, atrophic rhinitis in pigs and bovine hemorrhagic septicemia in cattle and buffalo. This study aimed to isolate P. multocida from sheep and cattle lungs sampled and assessed by bacteriological procedures and pulse field gel electrophoresis (PFGE) characterization. In this study 52 isolated of P. multocida were obtained (2016-2017) from clinically healthy and diseased animals (sheep and cattle) evaluated by PFGE for determining the relationship between them. According to the results of this study 12 sheep isolates had similarities above 94.00% and two cattle isolates showed similarities above 94.00%. When compared between sheep and cattle, most isolates showed a similarity of less than 50.00% indicating the great differences between isolates. It is noteworthy that in the present study, performed by PFGE to determine the type of P. multocida isolates, a very high distinction was made to determine the type of isolates and the relationship between isolates based on fragments in their genome using enzymes.

Effects of chemically EGFR targeting on non-targeted physical cell behaviors in 2D and 3D microfluidic cultures of invasive and non-invasive breast cancer cell lines

Cancer development comprehends changes in cell structural and physical states. Cancer cells are softer than normal cells, produce higher contractile forces, and migrate more easily. While chemotherapy, targets proteins involved in biological behaviors, it may affect cell physicomechanical state due to the interconnections among signaling pathways. Here we treated non-invasive and invasive breast cancer cell lines by targeting EGRF which modulates major biological behaviors. We quantified migration potential of cancer cells in a microfluidic device, and evaluated expression of proteins associated with physical behaviors. Results indicated significant alterations in physical behaviors, with a higher impact on invasive cells. The anti-cancer synergy between biological and physical behaviors was shown by decreasing actin, vinculin, and myosin II content and altered distribution, limiting cell invasion in 3D collagen structure, accompanied by decreasing cell viability and vimentin expression as the EMT biomarker. The center point of changes in physical behaviors was in cytoskeletal remodeling by chemical treatment, potentially through lower contractile force generation and less development of focal adhesions and stress fibers. The synergy between physical and chemical pathways can be used in enhancing anti-cancer drug efficacy.

Identification of Bordetella bronchiseptica in the throat and nose of dogs and cats by PCR

B.bronchiseptica is pathogenic for some domestic and wild animals. Due to the importance of this bacterium, its presence in dogs and cats has been investigated using PCR. Pharyngeal and nasal swabs were taken from 135 dogs and 42 cats. Based on the PCR performed on the dogs' samples, in 25/63 (39.68%) pharyngeal samples and 20/59 (33.89%) nasal samples DNA of B. bronchiseptica detected. On the other hand, according to the PCR performed on the cats' samples, in 9/23 (39.13%) pharyngeal samples and 319 (15.78%) nasal samples DNA of B. bronchiseptica was existed. According to the present study, the rate of B. bronchiseptica infection is high among dogs and cats in Iran. Also, due to the fact that the prevalence of this bacterium among pets animals is not exactly known in Iran, necessary measures should be taken for rapid diagnosis and treatment and proper control of the infection.

A phenotypic and molecular investigation of biofilm formation in clinical samples of Pseudomonas aeruginosa

Pseudomonas aeruginosa is identified as a versatile opportunistic microorganism with metabolic diversity contributing to a wide range of health burdens, especially in immunocompromised patients. This bacterium is the cause of 10 to 20% of nosocomial infections. In this study, we evaluated the phenotypic characterizations of biofilm formation in P. aeruginosa clinical isolates using micro-titer plate assay. Indeed, we estimated the prevalence of QS (rhlI, rhlR, rhlAB, lasB, lasI, lasR, aprA) and virulence genes (pslA and cupA) by PCR. The results showed that among 69% of the isolates forming biofilm, 9% were strong biofilm producers, whereas 13% and 47% of isolates produced moderate and low amounts of biofilm, respectively. All isolates possessed cupA and seven QS genes (rhlI, rhlR, rhlAB, lasB,  lasI, lasR, aprA), while 92% of the isolates possessed the pslA gene. Identification of these genes and their association with biofilm formation can be advantageous in adopting therapeutic methods.

A novel approach of recombinant laterosporulin production using the N-SH2 domain of SHP-2

Background

The current study was aimed at evaluating the role of the N-SH2 domain of SHP-2 as a partner protein in the expression of a toxic peptide, laterosporulin (LTS). We also investigated its effects on the formation of the disulfide bond and functional folding of the peptide in vitro. The N-SH2-LTS protein was expressed as a His-tagged fusion protein, capable of undergoing enzymatic cleavage.

Results

Based on the data presented herein, the total yield of the folded fusion protein from inclusion bodies was found to be about 105 mg/l, demonstrating a high-level of heterologous expression. After enzymatic cleavage, 1.5 mg of the folded recombinant laterosporulin was obtained from each 10 mg of the fusion protein. The purity of the recombinant laterosporulin was analyzed by RP-HPLC, to yield peptides with suitable purity (85%).

Conclusions

Our findings indicated the advantages of using the N-SH2 domain of SHP-2 as a rapid and easy approach not only in producing easy target proteins but also in its function as a chaperone. N-SH2 domain of SHP-2 can influence on the purification of laterosporulin at reasonable yield and in a cost-effective fashion. The N-SH2 domain of SHP-2 as a protein chaperone may be potentially favorable to produce other proteins with disulfide bonds.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12896-021-00721-7.

Chemical inhibitor anticancer drugs regulate mechanical properties and cytoskeletal structure of non-invasive and invasive breast cancer cell lines: Study of effects of Letrozole, Exemestane, and Everolimus

Regardless of their target and mechanism, anticancer drugs directly influence biological behavior of cancer cells by activating chemical signaling pathways. Due to the complex interaction between diverse signaling pathways, these drugs may profoundly impact the physical characteristics of cancer cells and regulate their mechanical properties. In this study, the effects of two Aromatase Inhibitor (Letrozole and Exemestane), and one mTOR Inhibitor (Everolimus) on cell mechanical properties, actin content/distribution, and nuclear areas of two invasive and non-invasive breast cancer cell line after 24 h treatment with concentrations previously reported were investigated. While metabolic activity of cell lines was highly affected by drug treatment, significant alterations in Young's modulus of cell bodies, nuclear areas, and actin content and distribution were reported with higher impact on invasive cells. It was concluded that regulation of mechanical behavior of cells by all three drugs emphasizes the cross talk between chemical and physical signaling cascades, and describes a correlation between biological and physical behaviors of cancer cells which might give an insight to a better understanding of mechanisms by which anti-cancer drugs function to enhance their performances.

Molecular characterization of lumpy skin disease virus in Iran (2014-2018)

Lumpy skin disease was first reported in the western provinces of Iran in 2014, and this was followed by several outbreaks throughout the country. In this study, 10 Iranian lumpy skin disease virus (LSDV) samples collected during the period of 2014-2018 were characterized by sequence analysis of the GPCR, LSDV142, and IL10LP genes. Sequence comparison of the respective genes revealed a close relationship between Iranian LSDV isolates and viruses from Asia and Europe. Interestingly, some nucleotide sequence diversity was also observed in the IL10LP genes of the Iranian field isolates.

Altered mechanical properties of actin fibers due to breast cancer invasion: parameter identification based on micropipette aspiration and multiscale tensegrity modeling

The biophysical properties of cells change with cancer invasion to fulfill their metastatic behavior. Cell softening induced by cancer is highly associated with alterations in cytoskeleton fibers. Changes in the mechanical properties of cytoskeletal fibers have not been quantified due to technical limitations. In this study, we used the micropipette aspiration technique to calculate and compare the viscoelastic properties of non-invasive and invasive breast cancer cells. We evaluated the mechanical properties of actin fibers and microtubules of two cancerous cell lines by using multiscale tensegrity modeling and an optimization method. Cancer invasion caused altered viscoelastic behavior of cells and the results of modeling showed changes in mechanical properties of major cytoskeleton fibers. The stiffness and viscosity constant of actin fibers in non-invasive cells were 1.28 and 2.27 times higher than those of the invasive cells, respectively. However, changes in mechanical properties of microtubules were minor. Immunofluorescent staining of fibers and their quantified distributions confirmed altered actin distribution among two cell lines, in contrast to microtubule distribution. This study highlights the function of cytoskeletal fibers in cancer progression, which could be of interest in designing therapeutic strategies to target cancer progress. Firstly, the viscoelastic behavior of non-invasive and invasive cells is examined with micropipette aspiration tests. A tensegrity model of cells is developed to mimic the viscoelastic behavior of cells, and tensegrity element stiffness is evaluated in an optimization procedure based on micropipette aspiration tests. Finally, by using immunofluorescent staining and confocal imaging, mechanical properties of actin filaments and microtubules of cancer cells are investigated during the course of metastasis.

Interleukin-8 gene expression and apoptosis induced by Salmonella Typhimurium in the presence of Bacillus probiotics in the epithelial cell

AIMS

This study aimed to evaluate the effects of three Bacillus probiotics on Salmonella Typhimurium, and interleukin-8 (IL-8) gene expression in the co-culture of the Bacillus and the pathogen in vitro.

METHODS AND RESULTS

Bacillus subtilis, Bacillus indicus and Bacillus coagulans were initially turned to spore and heat-inactivated forms. The cellular damages of the probiotics on the HT-29 cells were investigated individually and in combination with S. Typhimurium using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and fluorescence assays. To extract cell free supernatants (CFS) of the probiotics, they were cultured in selective media. The inhibitory activity of CFSs were then assayed against the pathogen. The gene expression of IL-8 of the HT-29 cells was evaluated by real-time PCR in all the groups. The results showed that the CFSs of three probiotics could inhibit the growth of S. Typhimurium by more than 50%. Inhibitory effects of B. indicus and B. subtilis CFSs were related to the production of pepsin-sensitive compounds, except B. coagulans in which the high inhibitory effect was due to organic acids. The spores of the three probiotics and the heat-inactivated forms of B. subtilis and B. coagulans could reduce the cytotoxicity of S. Typhimurium. The cell viability also increased applying both forms probiotics against the pathogen. In all co-culture groups, the IL-8 gene expression induced by S. Typhimurium was reduced.

CONCLUSIONS

The three Bacillus probiotics can be considered as proper candidates for the prevention and treatment of S. Typhimurium food poisoning.

SIGNIFICANCE AND IMPACT OF THE STUDY

Applying probiotics as live bacteria is universally noted in foods. This study tried to discover the effects of Bacillus probiotics in the form of spore or even heat-killed bacteria against S. Typhimurium and evaluate ratio of IL-8 gene expression in cell culture. The most effective Bacillus probiotic will be recommended. This approach will help to use probiotics as nonvegetative cells in foods to fight gastrointestinal pathogens.

The prevalence rate of sexual violence worldwide: a trend analysis

BACKGROUND

The purpose of the present study is to showcase the image of Sexual Violence (SV) temporal trends through exploring differences in its prevalence rates during 1990-2017 across 195 countries and territories.

METHODS

The SV prevalence rates were derived from the Global Burden of Disease (GBD) database during 1990-2017, worldwide. First, the Latent Growth Model (LGM) was employed for assessing the change in SV prevalence rate over time in Asia, Africa, Europe, North America, South America, Australia & Oceania, for men and women separately. Then, the change in SV prevalence rate over time was determined within countries with high and low Human Development Index (HDI). Finally, the Latent Growth Mixture Models (LGMM) were applied for identifying classes where countries within each class have similar trend of SV prevalence rate over time.

RESULTS

The SV prevalence was higher among women than men and decreased in both genders over time across the world. The declining trend in SV prevalence against men is visible in both countries with high and low HDI, but SV prevalence against women in countries with low HDI shows an increase. The findings of LGMM identified six classes of SV prevalence trajectories. LGMM allocated Bermuda into the class with the highest decrease in SV prevalence against men, and Equatorial Guinea and Luxembourg into the class with the highest increase. Other countries had very slow declining trends. In terms of SV prevalence against women, LGMM allocated China, North Korea, and Taiwan into the class with the most increase among the countries in the world. Bermuda, Guyana, Mexico, Nigeria, and Saint Lucia were placed into the class which witnessed the largest decline and Angola, Congo, and Equatorial Guinea were ranked next. The trend in other countries was mostly decreasing.

CONCLUSION

Given the high economic and social burden that SV has on victims and societies, the rate of SV in most countries does not seem to have dropped remarkably and requires special attention by relevant policymakers. The SV prevalence rate is highly heterogeneous among world countries which may be due to the definitions and tools used, and more importantly, the culture norms.

Leader-following group consensus of discrete-time fractional-order double-integrator multi-agent systems

The current study concerns with the leader-following group consensus issue for discrete-time fractional-order multi-agent systems. The agents are assumed as fractional-order double-integrators. The interconnection among the agents is characterized by a bidirectional fixed graph. By considering some assumptions on the interaction graph, it is proved that leader-following group consensus will be realized if the controller parameters lie in a specific two-dimensional region. In the beginning, the proposed distributed control structure's ability is evaluated for two groups with two leaders. Then, it is extended to an arbitrary number of groups with an arbitrary number of leaders. Simulation results indicate the efficiency of this distributed control structure.

Development of a double-recombinant antibody sandwich ELISA for quantitative detection of epsilon toxoid concentration in inactivated Clostridium perfringens vaccines

Background

Epsilon toxin (ETX) causes a commonly fatal enterotoxemia in domestic animals. Also, ETX causes serious economic losses to animal husbandry. In this study, we selected several clones against ETX using repertoires displayed on filamentous phage. Anti-ETX specific clones were enriched by binding to immobilized antigen, followed by elution and re-propagation of phage. After multiple rounds of binding selection, ELISA analysis showed that most isolated clones had high affinity and specificity for ETX.

Results

Two recombinant monoclonal antibodies against ETX were isolated by phage display technology. B₁ phage VH antibody isolated from DAb library and G₂ soluble scFv antibody isolated from Tomlinson I + J libraries have been applied as the capture and detection antibodies for developing an ETX sandwich ELISA test, respectively.

Conclusions

Designed ETX sandwich ELISA could be a valuable tool for quantitative detection of ETX in inactivated commercial vaccines against enterotoxemia.

Graphical abstract

Medullary thyroid cancer is associated with high serum vitamin D level and polymorphism of vitamin D receptors

Background

Thyroid cancer is the most common endocrine malignancy. Studies have observed an anti-cancer effect for vitamin D and found that polymorphisms of vitamin D receptors can influence the prevalence of various cancers. The present study investigated the serum level of vitamin D and FokI, BsmI and Tru9I polymorphisms of vitamin D receptors.

Methods

Forty patients with medullary thyroid cancer and 40 healthy controls were investigated. The genomic DNA of the subjects was extracted using saturated salt/proteinase K and investigated by PCR sequencing. Serum levels of vitamin D were evaluated by ELISA. The results were analyzed in SPSS and GraphPad Prism 5 software.

Results

The genotypic and allelic frequencies of FokI and BsmI polymorphisms showed no significant differences between test and control groups. For Tru9I polymorphism, Tt genotype and t allelic frequency in the test group were significantly different from those of the control group. Also, we found Tt genotype and t allelic frequency to be significantly associated with medullary thyroid cancer (MTC) type and the agressiveness of the disease. The average serum vitamin D level was 23.32 ng/mL and 18.95 ng/mL for patients and controls, respectively, and the difference between the two groups was statistically significant. Moreover, we found high serum vitamin D level to be associated with t allelic frequency.

Conclusions

Unexpectedly, the mean serum vitamin D level of the test group was significantly higher than that of the control group. Tru9I polymorphism was found to be significantly correlated with the prevalence of medullary thyroid carcinoma.

CO2 utilization: Turning greenhouse gas into fuels and valuable products

This study critically reviews the recent developments and future opportunities pertinent to the conversion of CO₂ as a potent greenhouse gas (GHG) to fuels and valuable products. CO₂ emissions have reached an alarming level of around 410 ppm and have become the primary driver of global warming and climate change leading to devastating events such as droughts, hurricanes, torrential rains, floods, tornados and wildfires across the world. These events are responsible for thousands of deaths and have adversely affected the economic development of many countries, loss of billions of dollars, across the globe. One of the promising choices to tackle this issue is carbon sequestration by pre- and post-combustion processes and oxyfuel combustion. The captured CO₂ can be converted into fuels and valuable products, including methanol, dimethyl ether (DME), and methane (CH₄). The efficient use of the sequestered CO₂ for the desalinization might be critical in overcoming water scarcity and energy issues in developing countries. Using the sequestered CO₂ to produce algae in combination with wastewater, and producing biofuels is among the promising strategies. Many methods, like direct combustion, fermentation, transesterification, pyrolysis, anaerobic digestion (AD), and gasification, can be used for the conversion of algae into biofuel. Direct air capturing (DAC) is another productive technique for absorbing CO₂ from the atmosphere and converting it into various useful energy resources like CH₄. These methods can effectively tackle the issues of climate change, water security, and energy crises. However, future research is required to make these conversion methods cost-effective and commercially applicable.

Isolation and identification of Pandoraea spp. From bronchoalveolar lavage of cystic fibrosis patients in Iran

Background

Pandoraea species are gram negative, motile, non-spore forming, rod shaped and oxidase positive, obligate aerobes bacteria, and have one polar flagellum. Most of Pandoraea species are associated with lung infections in cystic fibrosis patients. Cystic fibrosis is the most prevalent autosomal recessive hereditary disease in the world that affects various organs of the body. The main important cause of death in these patients is lung involvement. This study was conducted to isolate and identify Pandoraea bacterium from bronchoalveolar lavage and sputum samples of cystic fibrosis patients in Shiraz, Iran.

Methods

In this research 31 samples of bronchoalveolar lavage and sputum were examined by culture and PCR method. Then confirmed isolates were evaluated for susceptibility to different antibiotics and ability to produce biofilm.

Results

The results of this study after cultivation, purification and DNA extraction led to the isolation of 4 Pandoraea bacterium by PCR using specific primers. Antibiotic susceptibility test were indicated all isolates were resistant to gentamicin, amikacin and imipenem and susceptible to ciprofloxacin, trimethoprim-sulfumethoxazole, piperacillin and tetracycline. Ability to create biofilm was indicated by some of Pandoraea isolates. According to findings of this study, ability to synthesis biofilm by Pandoraea isolates and resistance to some antibiotics are very important.

Conclusions

Our study notes the role of P. pnomenusa as an emerging pathogen that can cause chronic lung colonization in CF patients. Identification tools need to be accurate and must be based on molecular techniques. Also our findings should raise awareness about antibiotic resistance in cystic fibrosis patients in Iran and ability of including bacterial agents to produce biofilm is an alarm for public health. Thus clinicians should exercise caution about finding of clinical relevance of this pathogen to the infection and prescribing antibiotics, especially in cases of children infections.

Profiling of how nociceptor neurons detect danger - new and old foes

The host evolves redundant mechanisms to preserve physiological processing and homeostasis. These functions range from sensing internal and external threats, creating a memory of the insult and generating reflexes, which aim to resolve inflammation. Impairment in such functioning leads to chronic inflammatory diseases. By interacting through a common language of ligands and receptors, the immune and sensory nervous systems work in concert to accomplish such protective functions. Whilst this bidirectional communication helps to protect from danger, it can contribute to disease pathophysiology. Thus, the somatosensory nervous system is anatomically positioned within primary and secondary lymphoid tissues and mucosa to modulate immunity directly. Upstream of this interplay, neurons detect danger, which prompts the release of neuropeptides initiating (i) defensive reflexes (ranging from withdrawal response to coughing) and (ii) chemotaxis, adhesion and local infiltration of immune cells. The resulting outcome of such neuro-immune interplay is still ill-defined, but consensual findings start to emerge and support neuropeptides not only as blockers of T_H 1-mediated immunity but also as drivers of T_H 2 immune responses. However, the modalities detected by nociceptors revealed broader than mechanical pressure and temperature sensing and include signals as various as cytokines and pathogens to immunoglobulins and even microRNAs. Along these lines, we aggregated various dorsal root ganglion sensory neuron expression profiling datasets supporting such wide-ranging sensing capabilities to help identifying new danger detection modalities of these cells. Thus, revealing unexpected aspects of nociceptor neuron biology might prompt the identification of novel drivers of immunity, means to resolve inflammation and strategies to safeguard homeostasis.

The effect of Bacillus coagulans on cytotoxicity and apoptosis induced by Salmonella Typhimurium in HT-29 cell culture

BACKGROUND AND OBJECTIVES

Human epithelial cells have been widely used to study the interaction between intestinal cells and pathogens, in vitro. In this study, the effect of probiotic bacteria Bacillus coagulans and its supernatant on the growth inhibition, cytotoxicity and induction of apoptosis caused by Salmonella Typhimurium and its adhesion to HT-29 cells were investigated.

MATERIALS AND METHODS

B. coagulans supernatant was used to obtain the minimum inhibitory concentration. To evaluate the cytotoxicity and percent of apoptotic cells, B. coagulans and its supernatant (2, 4, 6 and 8% concentrations) with S. Typhimurium was added to HT-29 cells. The MTT assay was used in order to evaluate the cytotoxicity. Percent of apoptotic cells was reported using a fluorescence staining method. Additionally, the adhesion of S. Typhimurium to HT-29 cells was investigated. The effect of B. coagulans on the level of adhesion was also studied.

RESULTS

The most inhibitory effect was shown at the concentration of 80000 μg/ml supernatant of B. coagulans (54.77% ± 1.43). The simultaneous culture of S. Typhimurium with B. coagulans had the lowest amount of cytotoxicity and induced apoptosis among the all co-culture groups of S. Typhimurium with B. coagulans or its supernatant. The determined cytotoxicity and induced apoptosis were 26.06 % ± 3.79 and 17.63 % ± 2.14 respectively. In the adhesion test, it was observed that B. coagulans can significantly prevent adhesion of S. Typhimurium to HT-29 cell.

CONCLUSION

B. coagulans can reduce the adhesion, cytotoxicity and induction of apoptosis caused by S. Typhimurium in HT-29 cells in vitro.

Traction Force Screening Enabled by Compliant PDMS Elastomers

Actomyosin contractility is an essential element of many aspects of cellular biology and manifests as traction forces that cells exert on their surroundings. The central role of these forces makes them a novel principal therapeutic target in diverse diseases. This requires accurate and higher-capacity measurements of traction forces; however, existing methods are largely low throughput, limiting their utility in broader applications. To address this need, we employ Fourier-transform traction force microscopy in a parallelized 96-well format, which we refer to as contractile force screening. Critically, rather than the frequently employed hydrogel polyacrylamide, we fabricate these plates using polydimethylsiloxane rubber. Key to this approach is that the polydimethylsiloxane used is very compliant, with a lower-bound Young's modulus of ∼0.4 kPa. We subdivide these monolithic substrates spatially into biochemically independent wells, creating a uniform multiwell platform for traction force screening. We demonstrate the utility and versatility of this platform by quantifying the compound and dose-dependent contractility responses of human airway smooth muscle cells and retinal pigment epithelial cells. By directly quantifying the endpoint of therapeutic intent, airway-smooth-muscle contractile force, this approach fills an important methodological void in current screening approaches for bronchodilator drug discovery, and, more generally, in measuring contractile response for a broad range of cell types and pathologies.

The effects of probiotic Bacillus coagulans on the cytotoxicity and expression of alpha toxin gene of Clostridium perfringens type A

Around the world, Clostridium perfringens type A is known to be a common foodborne pathogen. Therefore, the control and treatment of food poisoning caused by this pathogen are important. This study investigated, in vitro, the effects of Bacillus coagulans and its culture extracts on alpha toxin gene expression, growth inhibition, cytotoxicity, and apoptosis induced by C. perfringens spore, germinated spore and its enterotoxin. Flow cytometry was used to evaluate the apoptosis rate, and MTT test was used to evaluate cytotoxicity. Minimum inhibitory concentration was also used to measure the percentage of inhibition in the broth medium. Finally, RT-qPCR was used to evaluate alpha toxin gene expression. The results showed that the B. coagulans culture extract was able to inhibit the growth of the germinated spore of C. perfringens. Moreover, treating the extract with pepsin can reduce growth in the broth medium. MTT and flow cytometry showed that both B. coagulans and its extract can significantly reduce the cytotoxicity and apoptosis rate induced by C. perfringens type A. In addition, it was shown that the co-culture of B. coagulans and C. perfringens decreases alpha toxin gene expression. The findings of this study indicate that B. coagulans, with growth inhibition and reduced expression of alpha toxin in C. perfringens, can reduce the cytotoxicity and apoptosis rate induced on HT-29 cells.

Control of depth of anaesthesia using fractional-order adaptive high-gain controller

This study presents a fractional-order adaptive high-gain controller for control of depth of anaesthesia. To determine the depth of anaesthesia, the bispectral index (BIS) is utilised. To attain the desired BIS, the propofol infusion rate (as the control signal) should be appropriately adjusted. The effect of the propofol on the human body is modelled with the pharmacokinetic-pharmacodynamic (PK/PD) model. Physical properties of the patient such as gender, age, height and a like determine the parameters of the PK/PD model. This necessitates us to employ an appropriate adaptive controller. To attain this goal, a fractional-order adaptive high-gain controller is constructed to solve the tracking problem for minimum phase systems with relative degree two (such as the PK/PD model). This leads to a time-varying gain adjusting according to a fractional-order adaptation mechanism. Simulation results performed on various patients (considering the external disturbance and the measurement noise) show the effectiveness of the proposed method.

Calculation of controllability and observability matrices for special case of continuous-time multi-order fractional systems

In this paper, controllability and observability matrices for pseudo upper or lower triangular multi-order fractional systems are derived. It is demonstrated that these systems are controllable and observable if and only if their controllability and observability matrices are full rank. In other words, the rank of these matrices should be equal to the inner dimension of their corresponding state space realizations. To reduce the computational complexities, these matrices are converted to simplified matrices with smaller dimensions. Numerical examples are provided to show the usefulness of the mentioned matrices for controllability and observability analysis of this case of multi-order fractional systems. These examples clarify that the duality concept is not necessarily true for these special systems.

Radiation therapy affects the mechanical behavior of human umbilical vein endothelial cells

Radiation therapy has been widely utilized as an effective method to eliminate malignant tumors and cancerous cells. However, subjection of healthy tissues and the related networks of blood vessels adjacent to the tumor area to irradiation is inevitable. The aim of this study was to investigate the consequent effects of fractionation radiotherapy on the mechanical characteristics of human umbilical vein endothelial cells (HUVECs) through alterations in cytoskeleton organization and cell and nucleus morphology. In order to simulate the clinical condition of radiotherapy, the HUVECs were exposed to the specific dose of 2 Gy for 1-4 times among four groups with incremental total dose from 2 Gy up to 8 Gy. Fluorescence staining was performed to label F-actin filaments and nuclei. Micropipette aspiration and standard linear solid model were employed to evaluate the elastic and viscoelastic characteristics of the HUVECs. Radiotherapy significantly increased cell elastic moduli. Due to irradiation, instantaneous and equilibrium Young's modulus were also increased. Radiotherapy diminished HUVECs viscoelastic behavior and shifted their creep compliance curves downward. Furthermore, gamma irradiation elevated the nuclei sizes and to a lesser extent the cells sizes resulting in the accumulation of F-actin filaments within the rest of cell body. Endothelial stiffening correlates with endothelial dysfunction, hence the results may be helpful when the consequent effects of radiotherapy are the focus of concern.

Isolation and identification of Mannheimia haemolytica by culture and polymerase chain reaction from sheep's pulmonary samples in Shiraz, Iran

Background and Aim:

Mannheimia haemolytica is a Gram-negative, non-motile, and non-spore-forming rod-shaped coccobacillus bacterium. On blood agar plate, it shows complete hemolysis. This bacterium constitutes a part of normal flora of the upper respiratory system of ruminants. It is considered as the opportunistic pathogen and the main factor of pneumonic pasteurellosis, which has caused a severe economic loss in sheep and cattle industries. Considering the prevalence of the disease in sheep and goat population in the dry and hot regions of the country in general and in Fars province in particular in the form of pneumonia, the purpose of this study was to isolate and identify the bacterium M. haemolytica from the lung tissues of sheep slaughtered in Shiraz abattoir through culturing and polymerase chain reaction (PCR) methods.

Materials and Methods:

In this study, a total of 2500 sheep’s lungs were evaluated for finding pneumonic effects. Then, 161 infected pneumonic samples of lung tissues were investigated by culture and PCR methods.

Results:

After cultivation, purification, and DNA extraction, 38 samples were found positive for M. haemolytica by cultivation and then all the 38 isolates were confirmed by PCR and multiplex PCR (mPCR). Results of this study indicated that culture and PCR are both practical in identification and isolation of this bacterium though culture is more time-consuming. The utilized mPCR has been more successful in the identification of the bacteria since it requires less time and cost.

Conclusion:

In this study, PCR as a superior method among other methods of bacteriology for fast examination of infectious diseases and mPCR, which is a valuable tool for identification of M. haemolytica in clinical samples of animals, was used.

Production of MPT-64 recombinant protein from virulent strain of Mycobacterium bovis

Tuberculosis (TB) is a zoonotic infectious disease common to humans and animals which has been caused by a rod shaped, acid fast bacterium, called Mycobacterium bovis. The rapid and sensitive detection is a great challenge for TB diagnosis. The virulent strains of Mycobacterium tuberculosis complex (MTBC) have 16 different regions of difference (RD) in their genome which encode some important antigens. The major protein of M. bovis 64 (MPT-64) is one of the main immune-stimulating antigens which are encode by RD-2 region. The aim of the present study was cloning, expression and purification of MPT-64 as a protein antigen of M. bovis in a prokaryotic system for the usage in the future diagnostic studies. In this experimental study, the mpt-64 gene with 687 bp has been proliferated from M. bovis whole genome by polymerase chain reaction (PCR) method. The PCR product has been digested by BamHI and HindIII restriction enzymes and cloned into pQE-30 plasmid. The recombinant protein has been expressed in the Escherichia coli M15 with induction by isopropyl-β-D-thiogalactopyranoside (IPTG). The expressed protein was analyzed on SDS-PAGE, and purified with Nitrilotriacetic acid (Ni-NTA) column. Finally, its biological properties were confirmed in Western blotting method using specific antibodies. Data showed the successful cloning of mpt-64 gene (as a 687 bp segment) in expression vector. The MPT-64 recombinant protein was ideally expressed and purified as a 24 kDa protein. The result of this study indicated that MPT-64 recombinant protein (24 kDa) has been successfully expressed and purified in a prokaryotic system, so this protein could be used for differential diagnosis of pathogenic and non-pathogenic Mycobacterium, in suspected BTB cases.

Mycobacterium avium subsp. paratuberculosis induces differential cytosine methylation at miR-21 transcription start site region

Mycobacterium avium subspecies paratuberculosis (MAP), as an obligate intracellular bacterium, causes paratuberculosis (Johne's disease) in ruminants. Plus, MAP has consistently been isolated from Crohn's disease (CD) lesions in humans; a notion implying possible direct causative effect for MAP in CD development. Infections caused by MAP are refractory to treatment and in many cases the treatment does not easily resolve the infection. Studying the molecular mechanisms of host-pathogen interaction is helpful in identifying possible drug targets. In this line, it has already been shown that in macrophages infected with various bacteria, including mycobacteria, micro RNA 21 (miR-21) is upregulated, a change that results in diminished macrophages clearance ability and favours pathogens survival within the cells. However, the molecular mechanism(s) by which the intracellular bacteria induce miR-21 expression is not known. In order to verify possible effects from epigenetic changes induced by intracellular bacteria, we studied the cytosine methylation changes at the transcription start regions of miR-21 in THP-1 macrophages infected with MAP. For this purpose, genomic DNA was extracted from infected cells and the methylation status at the region of interest was evaluated by bisulfite conversion method. Our work showed that MAP directs de-methylation of the cystosines at CpG di-nucleotides in this region, while non-CpG cytosines of this region did not show significant changes. Interestingly, the CpG cytosines that were differentially methylated in the infected macrophages occur at the binding sites of the transcription factors already known to regulate miR-21 expression.

Vaccination with human amniotic epithelial cells confer effective protection in a murine model of Colon adenocarcinoma

As a prophylactic cancer vaccine, human amniotic membrane epithelial cells (hAECs) conferred effective protection in a murine model of colon cancer. The immunized mice mounted strong cross-protective CTL and antibody responses. Tumor burden was significantly reduced in tumor-bearing mice after immunization with hAECs. Placental cancer immunotherapy could be a promising approach for primary prevention of cancer. In spite of being the star of therapeutic strategies for cancer treatment, the results of immunotherapeutic approaches are still far from expectations. In this regard, primary prevention of cancer using prophylactic cancer vaccines has gained considerable attention. The immunologic similarities between cancer development and placentation have helped researchers to unravel molecular mechanisms responsible for carcinogenesis and to take advantage of stem cells from reproductive organs to elicit robust anti-cancer immune responses. Here, we showed that vaccination of mice with human amniotic membrane epithelial cells (hAECs) conferred effective protection against colon cancer and led to expansion of systemic and splenic cytotoxic T cell population and induction of cross-protective cytotoxic responses against tumor cells. Vaccinated mice mounted tumor-specific Th1 responses and produced cross-reactive antibodies against cell surface markers of cancer cells. Tumor burden was also significantly reduced in tumor-bearing mice immunized with hAECs. Our findings pave the way for potential future application of hAECs as an effective prophylactic cancer vaccine.

Generalized characteristic ratios assignment for commensurate fractional order systems with one zero

In this paper, a new method for determination of the desired characteristic equation and zero location of commensurate fractional order systems is presented. The concept of the characteristic ratio is extended for zero-including commensurate fractional order systems. The generalized version of characteristic ratios is defined such that the time-scaling property of characteristic ratios is also preserved. The monotonicity of the magnitude frequency response is employed to assign the generalized characteristic ratios for commensurate fractional order transfer functions with one zero. A simple pattern for characteristic ratios is proposed to reach a non-overshooting step response. Then, the proposed pattern is revisited to reach a low overshoot (say for example 2%) step response. Finally, zero-including controllers such as fractional order PI or lag (lead) controllers are designed using generalized characteristic ratios assignment method. Numerical simulations are provided to show the efficiency of the so designed controllers.

Cloning, expression, and purification of recombinant protein MPT-64 from a virulent strain of Mycobacterium bovis in a prokaryotic system

OBJECTIVE

Tuberculosis (TB) is a zoonotic infectious disease common to humans and animals that is caused by the rod-shaped acid-fast bacterium Mycobacterium bovis. Rapid and sensitive detection of TB is promoted by specific antigens. Virulent strains of the TB complex from M. bovis contain 16 regions of difference (RD) in their genome that encode important proteins, including major protein of Mycobacterium Tuberculosis 64 (MBT-64, which is a primary immune-stimulating antigen encoded by RD-2. In this study, we cloned, expressed, and purified MPT-64 as a potent M. bovis antigen in a prokaryotic system for use in future diagnostic studies.

METHODS

The antigenic region of the Mpt64 gene was investigated by bioinformatics methods, cloned into the PQE-30 plasmid, and expressed in Escherichia coli M15 cells, followed by isopropyl β-d-1-thiogalactopyranoside induction. The expressed protein was analyzed sodium dodecyl sulfate polyacrylamide gel electrophoresis and purified using a nickel-affinity column. Biological activity was confirmed by western blot using specific antibodies.

RESULTS

Our data verified the successful cloning of the Mpt64 gene (687-bp segment) via the expression vector and purification of recombinant MPT-64 as a 24-kDa protein.

CONCLUSION

These results indicated successful expression and purification of recombinant MPT-64 protein in a prokaryotic system. This protein can be used for serological diagnosis, improved detection of pathogenicity and non-pathogenicity between infected cattle, and for verification of suspected cases of bovine TB.

Isolation and identification of Legionella spp. from different aquatic sources in south-west of Iran by molecular &culture methods

Legionella pneumophila, the causative agent of Legionnaires' diseases (LD) is usually transmitted to humans via inhalation of aerosols from contaminated natural and manmade water sources. These organisms may become fatal especially in immunocompromised patients and LD is the one of the important disease from a public health perspective. This survey investigated the frequency of Legionella spp. including L. pneumophila, in some cold and warm water systems in South-West of Iran by culture and PCR methods. Thirty four water samples were collected from diverse water supply systems. After acid and heat treatments of samples, inoculated onto buffered charcoal yeast extract agar. Isolated colonies were confirmed by morphological and biochemical tests. Then the isolates were examined for icmO, sidA and lidA genes by PCR assay. This study showed that frequency of L. pneumophila was 4 by culture and 14 by PCR. PCR method to be efficient and sensitive test for rapid detection of these organisms in environmental water sources. This study emphasizes the need for effective infection control and prevention strategies to minimize the risk from exposure to potential pathogens such as Legionella spp. and to create a safe working environment.

Molecular characterization of Pasteurella multocida isolates obtained from poultry, ruminant, cats and dogs using RAPD and REP-PCR analysis

In the present study, Randomly Amplified Polymorphic DNA (RAPD) and Repetitive Extragenic Palindromic sequence-based Polymerase Chain Reaction (REP- PCR) were used to characterize 131 isolates of Pasteurella multocida, originating from different healthy and diseased animal species obtained from several geographical regions of Iran. The RAPD and REP-PCR generated amplified products in the range of 300 to 3400 bp and 200 to 2850 bp, respectively. Among all of the P. multocida isolates, cluster analysis revealed that 63 clusters and nine untypable isolates and 81 clusters and six untypable isolates were produced with RAPD and REP-PCR methods, respectively. The results indicated that the REP-PCR method showed a slightly higher level of discrimination power in differentiating of P. multocida isolates as compared with RAPD. The results showed that a considerable level of genetic diversity exists among P. multocida isolates even in the isolates with the same animal or geographical origins. There was no host- and region-specific pattern. In addition, the isolates obtained from the healthy and diseased animal did not reveal any correlation genotypic profiles, which could be supported by the hypothesis that P. multocida is a strictly opportunistic pathogen. In conclusion, because of a large amount of genetic heterogeneity in the P. multocida isolates, Pasteurellosis may be caused by different clones in the same herd or animal.

Prevalence and antibiotic resistance profile of thermophilic Campylobacter spp. of slaughtered cattle and sheep in Shiraz, Iran

Although poultry meat is considered as the main source for human Campylobacter infections, there is limited information about non-poultry sources. The present study was aimed to investigate the prevalence and the antibiotic resistance of thermophilic Campylobacter spp. in fecal samples of the cattle and sheep in Shiraz, Iran. A total of 302 fecal samples were obtained from clinically healthy, slaughtered cattle and sheep from Shiraz slaughterhouse. The animals were clinically healthy before being slaughtered. The samples were cultured according to the specific cultivation method under thermophilic conditions. The susceptibility of Campylobacter isolates were determined for 13 antimicrobial agents. All enriched samples and cultured isolates were targeted for polymerase chain reaction (PCR) detection of 16S rRNA and multiplex PCR for determining their species. Among 302 fecal samples, 65 (21.5%) and 205 (67.8%) samples were positive for the presence of Campylobacter species with the cultivation and PCR techniques, respectively. All 65 distinct isolates were susceptible to neomycin and colistin and the isolates showed high resistance to cephalotin (83.0%) and ciprofloxacin (67.7%). After the multiplex PCR, 78.5% of total positive samples showed the simultaneous presence of Campylobacter jejuni and Campylobacter coli. In conclusion, the results emphasized that non-poultry farms are important as a possible source of Campylobacter infections.

Occurrence and antimicrobial resistance of emergent Arcobacter spp. isolated from cattle and sheep in Iran

This study is conducted to determine the occurrence and antimicrobial resistance of Arcobacter spp. isolated from clinically healthy food animals. A total of 308 samples from cattle (200) and sheep (108) were collected from Shiraz slaughterhouse, southern Iran to investigate the presence of the important Arcobacter spp. using cultivation and Polymerase Chain Reaction (PCR) methods. Antimicrobial susceptibility of Arcobacter isolates was determined for 18 antibiotics using disk diffusion method. Among 308 samples, 27 (8.7%) and 44 (14.28%) were positive for the presence of Arcobacter species with cultivation and PCR procedures, respectively. The predominant species was A. butzleri in both cattle (58.33%) and sheep (55%). In addition, concurrent incidence of the species was observed in 25% of the positive samples. All Arcobacter isolates were resistant to rifampicin, vancomycin, ceftriaxone, trimethoprim and cephalothin. The isolates showed high susceptibility to tetracycline, oxytetracycline, erythromycin, ciprofloxacin, kanamycin, amikacin, gentamicin and enrofloxacin. No significant difference among cattle and sheep isolates in resistance pattern was observed. The results indicate that cattle and sheep are significant intestinal carriers for Arcobacter spp. Moreover, tetracycline and aminoglycosides showed great effects on Arcobacter species in antibiogram test and can be used for treatment of human Arcobacter infections.

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.

Tetracycline Resistance Genes in Campylobacter jejuni and C. coli Isolated From Poultry Carcasses

Background:

Campylobacter is one of the leading bacterial species causing foodborne illnesses in humans. Antimicrobial agents have been extensively used for treatment of Campylobacter infections; but in the recent years, both animal and human isolates of this bacterium have shown resistance to several antibiotics such as tetracycline.

Objectives:

The aim of this study was to investigate the presence of genetic determinants of tetracycline resistance in Campylobacter spp. recovered from poultry carcasses in Shiraz, Iran.

Materials and Methods:

Eighty-three thermophilic Campylobacter spp. Isolates were first identified based on multiplex polymerase chain reaction (PCR) and then screened for presence of tetracycline resistance genes (tet (A), tet (B), tet (O) and te (S)) by PCR.

Results:

The overall prevalence of Campylobacter jejuni and C. coli among the examined isolates was 51.8% and 48.2%, respectively. Tetracycline resistance genes of tet (B) and tet (S) were not seen among these Campylobacter spp. Isolates, whereas the most common tet gene identified was tet (O), found in 83.1% (69/83) of all the isolates. The tet (O) gene sequence comparison between C. jejuni and C. coli showed 100% similarity and these sequences (JX853721and JX853722) were also identical to the homologous sequences of other strains of Campylobacter spp. existing in the GenBank databases. In addition, tet (A) was found in 18% (15/83) of Campylobacter spp. isolates. To our knowledge, this represents the first report of tet (A) in Campylobacter spp. There was 100% homology between the sequences of tet (A) from this study (JX891463 and JX891464) and the tet (A) sequences mentioned for other bacteria in the GenBank databases.

Conclusions:

The high prevalence of tet (O) resistance gene along with new detection of tet (A) resistance gene in Campylobacter spp. isolated from poultry carcasses revealed an extensive tetracycline resistance among Campylobacter isolates from poultry in Iran. It emphasized the need for cautious use of tetracycline in poultry production to decrease the extension of tetracycline-resistant Campylobacter spp.