The effector-triggered immunity landscape of tomato against Pseudomonas syringae.

Tomato (Solanum lycopersicum) is one of the world's most important food crops, and as such, its production needs to be protected from infectious diseases that can significantly reduce yield and quality. Here, we survey the effector-triggered immunity (ETI) landscape of tomato against the bacterial pathogen Pseudomonas syringae. We perform comprehensive ETI screens in five cultivated tomato varieties and two wild relatives, as well as an immunodiversity screen on a collection of 149 tomato varieties that includes both wild and cultivated varieties. The screens reveal a tomato ETI landscape that is more limited than what was previously found in the model plant Arabidopsis thaliana. We also demonstrate that ETI eliciting effectors can protect tomato against P. syringae infection when the effector is delivered by a non-virulent strain either prior to or simultaneously with a virulent strain. Overall, our findings provide a snapshot of the ETI landscape of tomatoes and demonstrate that ETI can be used as a biocontrol treatment to protect crop plants.

Domestic and game pigeons as reservoirs for Escherichia coli harbouring antimicrobial resistance genes.

OBJECTIVES: In Iran, pigeons are kept and bred on the roofs of houses, which indicates the potential significance of pigeons in the dispersal of antimicrobial resistant Escherichia coli strains. Here we characterized antimicrobial resistance genotypes in relation to phenotypic presentations and phylogenetic backgrounds of the E. coli isolates from household pigeons in Kerman in southeast Iran. METHODS: Totally, 152 faecal E. coli isolates from domestic and household pigeons were screened for 13 antimicrobial resistance genes, blaTEM, blaSHV, blaCTX-M, sulI, sulII, dhfrI, dhfrV, aadA, aac(3)-I, tetA, tetB, floR and qnrA, by conventional polymerase chain reaction (PCR) technique. Clermont phylogenetic background of E. coli strains was studied and antibiotic resistance of all strains was assessed for seven antibiotics. RESULTS: The antimicrobial resistance genes blaTEM, tetA, tetB and aadA were detected in 52.6%, 6.5%, 6.5% and 5.9% of the isolates, respectively. PCR phylotyping revealed that a significant number of isolates within A0 (54%), A1 (70%), B1 (57.6%), B22 (75%) and D1 (87.5%) phylogroups were positive for the studied resistance genes. One phenotypic resistance pattern (trimethoprim-sulfamethoxazole) was associated with the presence of the corresponding gene sul2. CONCLUSIONS: An alarming rate of phenotypic resistance was observed in this study. Many isolates were positive for the screened resistance genes. According to the phylogenetic background, most resistant isolates belonged to the commensal phylotypes, representing significant role of commensal strains as a source of resistance genes. These findings highlight the role of the pigeon as disseminator of resistant E. coli strains.

Molecular investigation of the colicinogenic Escherichia coli strains that are capable of inhibiting E. coli O157:H7 in vitro.

BACKGROUND: Escherichia coli O157:H7 is a highly virulent human pathogen with severe consequences following infection, which claims many lives worldwide. A suggested method for controlling this bacterium is the competitive elimination through using probiotic bacteria that prevent its colonization. Some nonpathogenic E. coli strains that produce antibacterial colicins are among these probiotic bacteria. We aimed to isolate and characterize the colicinogenic E. coli strains from diarrheic and healthy sheep that inhibit E. coli O157:H7, which could be used as possible probiotic sources. A total of 292 E. coli isolates (146 from each diarrheic and healthy sheep) were screened for the presence of colicin and virulence genes. The phylogenetic group/subgroup determination was performed by PCR. In vitro evaluation of inhibitory effect of colicinogenic isolates on E. coli O157:H7 was done phenotypically. RESULTS: The frequency of diarrhea associated colicinogenic E. coli isolates was significantly higher than those isolated from healthy sheep. An association between ETEC and the genes coding for colicin-V & colicin-Iab in diarrheic E. coli isolates was observed. Moreover, there was an association between ipaH and Colicin-V encoding genes. Furthermore, E. coli isolates showing bacteriocinogeny while possessing no virulence genes had a frequency of 97.67 and 11.94% in healthy and diarrheic isolates, respectively. Of these strains, five isolates (3.42%) from diarrheic and twenty-five isolates (17.12%) from healthy sheep inhibited O157:H7 strain. Additionally, colicin E1 and colicin Iab genes were more prevalent in B1 phylogroup. CONCLUSIONS: These results signified that healthy sheep could be considered as a potential source for anti-O175:H7 bacterial isolates.

DISC1 gene polymorphisms and the risk of schizophrenia in an Iranian population: A preliminary study.

BACKGROUND: Schizophrenia, schizoaffective disorder, and bipolar illness are common psychological disorders with high heritability and variable phenotypes. The disrupted in schizophrenia 1 ( DISC1) gene, on chromosome 1q42, has an essential role in neurite outgrowth and cell signaling. The purpose of this study was to investigate the association of three single-nucleotide polymorphisms (SNPs; rs6675281, rs2255340, and rs2738864) with schizophrenia disorder. These three SNPs were chosen as they had been used in most of the previous studies. METHODS: In a case-control study of Iranian population for the first time 778 blood samples were collected including, 402 schizophrenic patients and 376 healthy controls. Genomic DNA was extracted from peripheral blood using DNA extraction kit (BioFlux Co). The genotypes of rs6675281, rs2255340, and rs2738864 were detected by nested allele-specific multiplex polymersae chain reaction (PCR). RESULTS: Our data revealed that the three SNPs are significantly associated with schizophrenia (rs2255349 C>T: confidence interval (CI), 2.115 to 3.268; P = 0.0000 OR: 2.629; rs2738864 C>T: CI, 1.538 to 2.339; P = 0.0000 OR: 1.897; rs6675281 C>T: CI, 2.788 to 4.662; P = 0.0009241 OR: 3.605). Through applying the expectation-maximization (EM) algorithm, we calculated the haplotype frequency, and finally performed haplotype analysis with Bonferroni correction and data preprocessing methods and the results showed rs66875281 to have the highest association. DISCUSSION: Our findings primarily showed that DISC1 gene polymorphisms contribute to schizophrenia risk and have a significant association with this disorder among Iranian population. The strategy was found to be easy, rapid, specific, and consistent for the co-occurring detection of the DISC1 polymorphisms. We could finally confirm that the polymorphisms are related to schizophrenia studied in Iranian population.

Genotypic analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs in Iran.

The aim of the present study was to determine the analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs. Two hundred ninety E. coli isolates were recovered from 300 rectal swabs of diarrheic lambs and were confirmed by biochemical tests. The pathotype determination was done according to the presence of genes including f5, f41, LTI, STI, bfp, ipaH, stx 1 , stx 2 , eae, ehlyA, cnf 1 , cnf 2 , cdIII, cdIV, and f17 by PCR method. Sixty-six isolates (23.72%) possessed the STI gene and categorized into entrotoxigenic E. coli (ETEC). Nine isolates (3.1%) and five isolates (1.72%) were positive for the cnf1 and cnf2 genes which categorized into necrotoxic E. coli (NTEC). Hundred and seventeen isolates (40.34%) harbored stx 1 and/or stx 2 and classified as Shiga toxin-producing E. coli (STEC). Thirteen isolates (4.48%) were assigned to atypical entropathogenic E. coli (aEPEC) and possessed eae gene. Two isolates (0.68%) were positive for ipaH gene and were assigned to entroinvasive E. coli (EIEC). Statistical analysis showed a specific association between eae gene and STEC pathotype (P < 0.0001). The most prevalent resistance was observed against lincomycin (96.5%) and the lowest resistance was against kanamycine (56.02%), respectively. The high prevalence of STEC and ETEC indicates that diarrheic lambs represent an important reservoir for humans. ETEC may play an important role for frequent occurrence of diarrhea in lambs observed in this region. Due to high antibiotic resistance, appropriate control should be implemented in veterinary medicine to curb the development of novel resistant isolates.

Microbiological, biochemical and organoleptic properties of fermented-probiotic drink produced from camel milk.

The microbiological and biochemical changes occurred during the fermentation of camel milk inoculated by three selected bacterial starter, were investigated as well as the sensory evaluation of the product. Milk samples were collected from camel herds of southeastern of Iran. Chr. Hansen ABT-10 starter including Lactobacillus acidophillus, Biphidobacterum biphidum and Sterptococcus thermophilus in ratio of 0.50 g per 100 mL of camel milk was added. This fermented product was examined at the 0, 3rd, 6th and 9th days for microbiological, biochemical and sensory evaluations. The results showed the number of starter bacteria was maintained at least 106 CFU mL-1 during nine test days. It was shown that it could be used as fermented-probiotic drink. The product did not show any microbial contamination. The acidity and protein amount of produced drink showed a significant (p < 0.05) increase in different test days. Fat, solids-not-fat and ash amount of the product showed significant differences at the ninths' test day compared to the zero test day (p < 0.05). Organoleptic properties of product including flavor, color, odor, consistency, mouth feel and overall acceptance were significantly improved (p < 0.05). Therefore, the produced fermented-probiotic drink, in addition to keep maintenance and increased nutritional quantity value, was accepted by consumers in terms of organoleptic properties and it could be used as a healthy and functional drink.

Congenital peritoneopericardial diaphragmatic hernia in a terrier dog.

A one-month-old male terrier dog was referred in shock status with a history of anorexia, tachypnea, abdominal distention and progressive weight loss. Auscultation of right side of the lungs found enhanced respiratory noises. The thorough auscultation of the opposite side of the chest revealed the presence of typical intestinal sounds. Cardiac auscultation revealed muffled heart sounds and a diminished palpable precordial cardiac impulse was evident. The radiograph showed the presence of gas within the bowel in abrupt contrast to the adjacent structures of soft tissue opacity. Conservative treatment was failed and the animal died. At necropsy, cranial displacement of abdominal viscera into the pericardial sac was seen. A definitive diagnosis of peritoneopericardial diaphragmatic hernia was made. Although congenital pericardial diseases are rare in dogs, awareness of the clinical manifestation of these kinds of defects combined with early use of available imaging modalities can yield a preoperative diagnosis.