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.

Comparison of the predictive value of the Helsinki, Rotterdam, and Stockholm CT scores in predicting 6-month outcomes in patients with blunt traumatic brain injuries.

PURPOSE: Despite advances in modern medicine, traumatic brain injuries (TBIs) are still a major medical problem. Early diagnosis of TBI is crucial for clinical decision-making and prognosis. This study aims to compare the predictive value of Helsinki, Rotterdam, and Stockholm CT scores in predicting the 6-month outcomes in blunt TBI patients. METHODS: This cohort study was conducted on blunt TBI patients of 15 years or older. All of them were admitted to the surgical emergency department of Shahid Beheshti Hospital in Kashan, Iran from 2020 to 2021 and had abnormal trauma-related findings on brain CT images. The patients' demographic data such as age, gender, history of comorbid conditions, mechanism of trauma, Glasgow coma scale, CT images, length of hospital stay, and surgical procedures were recorded. The Helsinki, Rotterdam, and Stockholm CT scores were simultaneously determined according to the existing guidelines. The included patients' 6-month outcome was determined using the Glasgow outcome scale extended. M Data were analyzed by SPSS software version 16.0. Sensitivity, specificity, negative/positive predictive value and the area under the receiver operating characteristic curve were calculated for each test. The Kappa agreement coefficient and Kuder Richardson-20 were used to compare the scoring systems. RESULTS: Altogether 171 TBI patients met the inclusion and exclusion criteria, with the mean age of (44.9 ± 20.2) years. Most patients were male (80.7%), had traffic related injuries (83.1%) and mild TBIs (64.3%). Patients with lower Glasgow coma scale had higher Helsinki, Rotterdam, and Stockholm CT scores and lower Glasgow outcome scale extended scores. Among all the scoring systems, the Helsinki and Stockholm scores showed the highest agreement in predicting patients' outcomes (kappa = 0.657, p < 0.001). The Rotterdam scoring system had the highest sensitivity (90.1%) in predicting death of TBI patients, whereas the Helsinki scoring system had the highest sensitivity (89.8%) in predicting the 6-month outcome in TBI patients. CONCLUSION: The Rotterdam scoring system was superior in predicting death in TBI patients, whereas the Helsinki scoring system was more sensitive in predicting the 6-month outcome.

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.

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.

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.

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.

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.

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.

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.

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.

Comparison of biofilm formation and antibiotic resistance pattern of Pseudomonas aeruginosa in human and environmental isolates.

Pseudomonas aeruginosa is an opportunistic human pathogen especially in patients with underlying diseases such as cyctic fibrosis and has been established as a model organism to study bacterial biofilm formation. The aim of this study was to compare the biofilm formation and antibiotic resistance in human and environmental P. aeruginosa isolates. Numbers of positive samples for algD and algU genes in human samples were 98% and the positive samples for algD and algU genes in the environmental samples were 80% and 70%, respectively. Ability to create biofilms by the human and environmental samples were 70% and 28%, respectively. The incidences of various antibiotic resistance genes in human samples including blaTEM and blaSHV were 92% and 16%, respectively but antibiotic resistance genes in environmental samples including blaTEM and blaSHV were 20% and 6%, respectively. High resistance to gentamicin (74%) and meropenem (70%), were found in the human samples, were as in the environmental samples high level of resistance were observed to ceftazidime (30%), gentamicin and meropenem (28%). According to findings of this study, differences in genes involve in biofilm synthesis between human and environmental isolates are highly significant and the environmental isolates of P. aeruginosa stile are sensitive to most antibiotics because they lacks the antibiotic resistance genes. But after transfer to human and isolation from diseased people have been taken the antibiotic resistance genes that would be resistant to many antibiotics.

Occurrence of virulence-associated genes in Pasteurella multocida isolates obtained from different hosts.

Pasteurella multocida infects a wide range of animals and the infection may spread to human through animal bites and scratches. Pasteurella multocida isolates, obtained from several clinically healthy and diseased animals (bovine, sheep, goat, poultry, dog and cat), were investigated for capsule biosynthesis (capA, B, D, E and F) and expression of 22 virulence-associated genes using Polymerase Chain Reaction (PCR). Multiplex PCR results revealed expression of capA, capD and capB genes in 81 (61.83%), 30 (22.90%) and 10 isolates (7.29%), respectively. However, neither of the isolates harbored capE or capF genes and ten isolates (7.29%) were negative for all cap genes. The expression of the capB gene was observed in small ruminant isolates. The occurrence of the ompA, ompH, oma87, sodA and sodC genes was noticed in all of the samples. More than 90% of the isolates harbored hgbA (96.18%), ptfA (95.41%), exbBD-tonB (93.12%), nanB (93.12%) and plbB genes (90.83%). The transferrin binding protein encoding gene tbpA was exclusively detected in the ruminant isolates. The limited number of isolates (25.95%) harbored dermonecrotoxin gene (toxA) and the highest occurrence was noted in the small ruminants, and the capsular type D isolates. This study highlights that the toxA, tbpA, and pfhA genes can be considered as important epidemiological markers for the characterization of P. multocida isolates.

Occurrence of six virulence-associated genes in Arcobacter species isolated from various sources in Shiraz, Southern Iran.

In humans, arcobacters are associated with watery diarrhea and septicemia. Although, recently, more cases of diarrhea have been caused by Arcobacter species, very little is known about its pathogenesis. Therefore, the aim of this study was to evaluate the presence of six putative Arcobacter virulence genes (cadF, ciaB, cj1349, mviN, pldA, and tlyA), in a set of 113 Arcobacter butzleri, 40 Arcobacter cryaerophilus, and 15 Arcobacter skirrowii isolates that were recovered from various origins. The isolates were confirmed on the basis of polymerase chain reaction (PCR) amplification of genus and species specific PCR for determining three species. For confirmed isolates, PCR was carried out for the presence of virulence genes using specific primers. All A. butzleri isolates carried all six genes. For A. cryaerophilus and A. skirrowii, the cadF gene was detected just in 55 and 53.3%, ciaB in 97.5 and 86.6%, cj1349 in 45 and 60%, mviN in 90 and 80%, pldA in 32.5 and 13.3%, and tlyA in 37.5 and 40%, respectively. For A. cryaerophilus and A. skirrowii, the genes ciaB and mviN were significantly more prevalent than other virulence markers (P ≤ 0.05). The findings revealed that many of the important Arcobacter strains (86%) have these putative virulence genes which can be potential pathogenic properties for humans.

Distribution of nine virulence-associated genes in Campylobacter jejuni and C. coli isolated from broiler feces in Shiraz, Southern Iran.

To investigate the prevalence of nine virulence and toxin genes of Campylobacter, a total of 90 Campylobacter strains including 48 C. jejuni and 42 C. coli were recovered from chicken feces by cultivation methods. The isolates were identified on the basis of polymerase chain reaction (PCR) detection of 16SrRNA and multiplex PCR for determining two species. For confirmed strains, PCR was carried out for the presence of virulence genes using specific primers. Data were analyzed by SPSS software, version 12.0.1. The cadF gene and three genes associated with cytolethal distending toxin were present in 100% of isolates. Plasmid virB11 gene was not found in any of the Campylobacter isolates, and the prevalence of pldA, wlaN, iamA, and cgtB genes were 92.22%, 82.22%, 81.11%, and 22.22%, respectively. The findings revealed that the distribution of the majority of these genes were not dissimilar among Campylobacter species. The results emphasized that many of the pathogenic C. jejuni and C. coli may have these genes, and the Campylobacter strains with poultry origin have pathogenic potential properties for humans.

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.

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.

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.

Auto-Segmentation and Classification of Glioma Tumors with the Goals of Treatment Response Assessment Using Deep Learning Based on Magnetic Resonance Imaging.

Glioma is the most common primary intracranial neoplasm in adults. Radiotherapy is a treatment approach in glioma patients, and Magnetic Resonance Imaging (MRI) is a beneficial diagnostic tool in treatment planning. Treatment response assessment in glioma patients is usually based on the Response Assessment in Neuro Oncology (RANO) criteria. The limitation of assessment based on RANO is two-dimensional (2D) manual measurements. Deep learning (DL) has great potential in neuro-oncology to improve the accuracy of response assessment. In the current research, firstly, the BraTS 2018 Challenge dataset included 210 HGG and 75 LGG were applied to train a designed U-Net network for automatic tumor and intra-tumoral segmentation, followed by training of the designed classifier with transfer learning for determining grading HGG and LGG. Then, designed networks were employed for the segmentation and classification of local MRI images of 49 glioma patients pre and post-radiotherapy. The results of tumor segmentation and its intra-tumoral regions were utilized to determine the volume of different regions and treatment response assessment. Treatment response assessment demonstrated that radiotherapy is effective on the whole tumor and enhancing region with p-value ≤ 0.05 with a 95% confidence level, while it did not affect necrosis and peri-tumoral edema regions. This work demonstrated the potential of using deep learning in MRI images to provide a beneficial tool in the automated treatment response assessment so that the patient can obtain the best treatment.

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.

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.