Mechanisms of photoreceptor mediated responses in photomorphogenesis and phototropism

Photoreceptor facilitated light perception provides plants with critical environmental information from which they can direct their growth. We investigated the early photomorphogenic responses in Glycine max and Glycine soja with the aim of elucidating the effect that domestication has had on early light responses. Our study indicates that G. max exhibits growth in darkness that is more characteristic of growth in light. This finding suggests that domestication has resulted in a crop species that is partially constitutively photomorphogenic. We additionally investigated the effects of blue light-induced ubiquitination sites that were ubiquitinated dependently by NON-PHOTOTROPIC HYPOCOTYL3 (NPH3) in the red light photoreceptor phytochrome A (phyA) in Arabidopsis thaliana. We discovered that transgenic lines expressing phyA with the ubiquitination sites K555 and K603 converted to non-ubiquitinatable arginine residues displayed reduced degradation in blue light and additionally reduced phototropic curvature in high intensity blue light, while functioning normally in other responses tested: very low and low intensity blue light phototropism, far-red light hypocotyl growth inhibition, and red light-induced phyA degradation. This finding suggests a mechanism for a more direct route of blue and red light-signaling crosstalk than has been previously shown.Includes bibliographical reference

Group A Streptococcus Brain Abscess in a Patient on Adalimumab Therapy

Brain abscesses represent a group of dangerous infections typically caused by a number of classic organisms. Group A Streptococcus is a rare cause of brain abscesses and those patients that do have this particular condition will typically have a distal source of infection. We present a case of patient with a biopsy confirmed Group A Streptococcal without a distal source of infection. His only identifiable risk factor was his adalimumab therapy for ankylosing spondylitis. While adalimumab has not been linked to Streptococcal infection in the past, it has been associated with multiple atypical infections and some of the consequences of its mechanism as a tissue necrosis factor alpha inhibitor can theoretically predispose patients to Streptococcal infection when considered in conjunction with known Streptococcal virulence factors. This case raises the question of whether the patient’s adalimumab therapy may have contributed to his unusual presentation of Streptococcal infection and prompts further consideration and study of the risks of adalimumab and other similar immunosuppressant monoclonal antibodies

Occupational Exposure to Streptococcus suis among US Swine Workers

Despite numerous cases of human infection with Streptococcus suis worldwide, human disease is rarely diagnosed in North America. We studied 73 swine-exposed and 67 non–swine-exposed US adults for antibodies to S. suis serotype 2. Serologic data suggest that human infection with S. suis occurs more frequently than currently documented

Streptococcus suis Meningitis, United States

Streptococcus suis Meningitis, United State

Streptococcus suis Meningitis with Bilateral Sensorineural Hearing Loss

Streptococcus suis infection is an emerging zoonosis in Asia. The most common disease manifestation is meningitis, which is often associated with hearing loss and cochleovestibular signs. S. suis infection in humans mainly occurs among risk groups that have frequent exposure to pigs or raw pork. Here, we report a case of S. suis meningitis in a 67-yr-old pig carcass handler, who presented with dizziness and sensorineural hearing loss followed by headaches. Gram-positive diplococci were isolated from cerebrospinal fluid (CSF) and blood cultures and showed gray-white colonies with α-hemolysis. S. suis was identified from CSF and blood cultures by using a Vitek 2 system (bioMérieux, France), API 20 STREP (bioMérieux), and performing 16S rRNA and tuf gene sequencing. Even after receiving antibiotic treatment, patients with S. suis infection frequently show complications such as hearing impairment and vestibular dysfunction. To the best of our knowledge, this is the first case of S. suis meningitis in Korea. Prevention through public health surveillance is recommended, especially for individuals who have occupational exposures to swine and raw pork

Molecular Dynamics Simulation of the Complex PBP-2x with Drug Cefuroxime to Explore the Drug Resistance Mechanism of Streptococcus suis R61

Drug resistance of Streptococcus suis strains is a worldwide problem for both humans and pigs. Previous studies have noted that penicillin-binding protein (PBPs) mutation is one important cause of β-lactam antibiotic resistance. In this study, we used the molecular dynamics (MD) method to study the interaction differences between cefuroxime (CES) and PBP2x within two newly sequenced Streptococcus suis: drug-sensitive strain A7, and drug-resistant strain R61. The MM-PBSA results proved that the drug bound much more tightly to PBP2x in A7 (PBP2x-A7) than to PBP2x in R61 (PBP2x-R61). This is consistent with the evidently different resistances of the two strains to cefuroxime. Hydrogen bond analysis indicated that PBP2x-A7 preferred to bind to cefuroxime rather than to PBP2x-R61. Three stable hydrogen bonds were formed by the drug and PBP2x-A7, while only one unstable bond existed between the drug and PBP2x-R61. Further, we found that the Gln569, Tyr594, and Gly596 residues were the key mutant residues contributing directly to the different binding by pair wise energy decomposition comparison. By investigating the binding mode of the drug, we found that mutant residues Ala320, Gln553, and Thr595 indirectly affected the final phenomenon by topological conformation alteration. Above all, our results revealed some details about the specific interaction between the two PBP2x proteins and the drug cefuroxime. To some degree, this explained the drug resistance mechanism of Streptococcus suis and as a result could be helpful for further drug design or improvement

Comparative Genomics Study of Multi-Drug-Resistance Mechanisms in the Antibiotic-Resistant Streptococcus suis R61 Strain

BACKGROUND: Streptococcus suis infections are a serious problem for both humans and pigs worldwide. The emergence and increasing prevalence of antibiotic-resistant S. suis strains pose significant clinical and societal challenges. RESULTS: In our study, we sequenced one multi-drug-resistant S. suis strain, R61, and one S. suis strain, A7, which is fully sensitive to all tested antibiotics. Comparative genomic analysis revealed that the R61 strain is phylogenetically distinct from other S. suis strains, and the genome of R61 exhibits extreme levels of evolutionary plasticity with high levels of gene gain and loss. Our results indicate that the multi-drug-resistant strain R61 has evolved three main categories of resistance. CONCLUSIONS: Comparative genomic analysis of S. suis strains with diverse drug-resistant phenotypes provided evidence that horizontal gene transfer is an important evolutionary force in shaping the genome of multi-drug-resistant strain R61. In this study, we discovered novel and previously unexamined mutations that are strong candidates for conferring drug resistance. We believe that these mutations will provide crucial clues for designing new drugs against this pathogen. In addition, our work provides a clear demonstration that the use of drugs has driven the emergence of the multi-drug-resistant strain R61

Brettanomyces bruxellensis yeasts: impact on wine and winemaking

Yeasts belonging to the Brettanomyces/Dekkera genus are non-conventional yeasts, which affect winemaking by causing wine spoilage all over the world. This mini-review focuses on recent results concerning the presence of Brettanomyces bruxellensis throughout the wine processing chain. Here, culture-dependent and independent methods to detect this yeast on grapes and at the very early stage of wine production are encompassed. Chemical, physical and biological tools, devised for the prevention and control of such a detrimental species during winemaking are also presented. Finally, the mini-review identifies future research areas relevant to the improvement of wine safety and sensory profiles