antibiotic selection
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Author(s):  
Sadagoban G. Krishnamoorthy ◽  
Vyshak Raj ◽  
Balasubramaniam Viswanathan ◽  
Ganga Priyadharshini Dhanasekaran ◽  
Dhivyaprasath Palaniappan ◽  
...  

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ye Zhang ◽  
Qing Sun ◽  
Yu Liu ◽  
Xuecong Cen ◽  
Dehua Liu ◽  
...  

AbstractVibrio natriegens is a promising industrial chassis with a super-fast growth rate and high substrate uptake rates. V. natriegens was previously engineered to produce 1,3-propanediol (1,3-PDO) from glycerol by overexpressing the corresponding genes in a plasmid. However, antibiotic selection pressure for plasmid stability was not satisfactory and plasmid loss resulted in reduced productivity of the bioprocess. In this study, we developed an antibiotic-free plasmid stabilization system for V. natriegens. The system was achieved by shifting the glpD gene, one of the essential genes for glycerol degradation, from the chromosome to plasmid. With this system, engineered V. natriegens can stably maintain a large expression plasmid during the whole fed-batch fermentation and accumulated 69.5 g/L 1,3-PDO in 24 h, which was 23% higher than that based on antibiotic selection system. This system was also applied to engineering V. natriegens for the production of 3-hydroxypropionate (3-HP), enabling the engineered strain to accumulate 64.5 g/L 3-HP in 24 h, which was 30% higher than that based on antibiotic system. Overall, the developed strategy could be useful for engineering V. natriegens as a platform for the production of value-added chemicals from glycerol. Graphic Abstract


Pharmacia ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 883-889
Author(s):  
Ahmed M. Magdy ◽  
Mahmoud A. Seksaka ◽  
Gehan F. Balata

Surgical site infection (SSI) constitutes a major problem in healthcare in terms of healthcare cost, morbidity and mortality. Surgical antibiotic prophylaxis (SAP) is one of the effective strategies for SSI prevention. Poor adherence to SAP guidelines across different countries has been observed. Misuse of prophylactic antibiotics threatens patient safety and leads to an increase in the acquisition of antibiotic resistance. The aim of this study was to assess the utilization of SAP in obstetric and gynecologic procedures in terms of indication for prophylaxis, antibiotic selection, timing of administration and prophylaxis duration. A prospective observational study was conducted at the obstetrics and gynecology department of Zagazig University Hospital during the period from January 2020 to June 2020. Medical records of 264 women were recorded and evaluated. The American Society of Health-System Pharmacists (ASHP) therapeutic guidelines, World Health Organization (WHO) recommendations and The American College of Obstetricians and Gynecologists (ACOG) practice bulletin were used for data evaluation and hence women were stratified into two groups. For women who underwent procedures in which guidelines recommended the use of SAP (200 patients; 75.75%), 198 women (99%) received preoperative prophylaxis. None of women (0%) received the recommended first line antibiotic by guidelines while the most commonly used prophylactic antibiotics were Cefotaxime (86 patients; 43.43%) and Ampicillin-sulbactam (62 patients; 31.31%). Preoperative antibiotic prophylaxis timing was 0-60 minutes before skin incision. All women received postoperative prophylaxis that extended to an average of 7 days. Regarding the other group who underwent procedures in which prophylactic antibiotics weren’t recommended by guidelines (64 patients; 24.24%), 37 women (57.81%) followed the guidelines and didn’t receive SAP while 27 women (42.18%) received SAP. Poor adherence to guidelines recommendations regarding prophylactic antibiotic selection and prophylaxis duration was observed. High utilization rate of prophylactic antibiotics in procedures that didn’t require their use was reported..


2021 ◽  
Vol 8 ◽  
Author(s):  
Anastasia Yunusova ◽  
Alexander Smirnov ◽  
Tatiana Shnaider ◽  
Varvara Lukyanchikova ◽  
Svetlana Afonnikova ◽  
...  

The auxin-inducible degron (AID) system is a promising tool for dynamic protein degradation. In mammalian cells, this approach has become indispensable to study fundamental molecular functions, such as replication, chromatin dynamics, or transcription, which are otherwise difficult to dissect. We present evaluation of the two prominent AID systems based on OsTIR1 and AtAFB2 auxin receptor F-box proteins (AFBs). We analyzed degradation dynamics of cohesin/condensin complex subunits in mouse embryonic stem cells (Rad21, Smc2, Ncaph, and Ncaph2) and human haploid HAP1 line (RAD21, SMC2). Double antibiotic selection helped achieve high homozygous AID tagging of an endogenous gene for all genes using CRISPR/Cas9. We found that the main challenge for successful protein degradation is obtaining cell clones with high and stable AFB expression levels due to the mosaic expression of AFBs. AFB expression from a transgene tends to decline with passages in the absence of constant antibiotic selection, preventing epigenetic silencing of a transgene, even at the AAVS1 safe-harbor locus. Comparing two AFBs, we found that the OsTIR1 system showed weak dynamics of protein degradation. At the same time, the AtAFB2 approach was very efficient even in random integration of AFB-expressed transgenes. Other factors such as degradation dynamics and low basal depletion were also in favor of the AtAFB2 system.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Shumaila Sarfani ◽  
Cosby A. Stone ◽  
G. Andrew Murphy ◽  
David R. Richardson

Author(s):  
Bridget Harvey ◽  
James Tarrant ◽  
Megan McClosky ◽  
Olivia Nathanson ◽  
Stephen Cole

ABSTRACT A 13 yr old spayed female Yorkshire terrier was hospitalized for a dull mentation, anorexia, presumptive gastroenterocolitis, and a suspected gastrointestinal bleed with melena. Despite supportive therapy, the patient’s clinical signs persisted. Throughout hospitalization, the patient became progressively dull to stuporous with a progressive hypernatremia. On day 3 of hospitalization, the patient acutely developed neurological signs with a neuroanatomical localization consistent with a process at the caudal cranial fossa. Per the owner’s wishes, the patient was euthanized with necropsy performed. Histo-pathology revealed a suppurative meningoencephalitis, ventriculitis, hypophysitis, otitis interna, and an ulcerative pharyngitis. Aerobic culture collected from the area of the pituitary gland grew an Enterococcus spp. Enterococcal meningoencephalitis is rare in humans but has not been reported in veterinary medicine. In future cases of canine bacterial meningitis, Enterococcus spp. should be considered. Because of the inherent resistance patterns of Enterococcus spp., targeted antibiotic selection would be required for treatment.


CHEST Journal ◽  
2021 ◽  
Vol 160 (4) ◽  
pp. A570
Author(s):  
George Tetz ◽  
Christina Kardava ◽  
Maria Vecherkovskaya ◽  
Victor Tetz

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Vishwa Patel ◽  
Nishad Matange

Gene regulatory networks allow organisms to generate coordinated responses to environmental challenges. In bacteria, regulatory networks are re-wired and re-purposed during evolution, though the relationship between selection pressures and evolutionary change is poorly understood. In this study, we discover that the early evolutionary response of Escherichia coli to the antibiotic trimethoprim involves derepression of PhoPQ signaling, an Mg2+-sensitive two-component system, by inactivation of the MgrB feedback-regulatory protein. We report that derepression of PhoPQ confers trimethoprim-tolerance to E. coli by hitherto unrecognized transcriptional upregulation of dihydrofolate reductase (DHFR), target of trimethoprim. As a result, mutations in mgrB precede and facilitate the evolution of drug resistance. Using laboratory evolution, genome sequencing, and mutation re-construction, we show that populations of E. coli challenged with trimethoprim are faced with the evolutionary ‘choice’ of transitioning from tolerant to resistant by mutations in DHFR, or compensating for the fitness costs of PhoPQ derepression by inactivating the RpoS sigma factor, itself a PhoPQ-target. Outcomes at this evolutionary branch-point are determined by the strength of antibiotic selection, such that high pressures favor resistance, while low pressures favor cost compensation. Our results relate evolutionary changes in bacterial gene regulatory networks to strength of selection and provide mechanistic evidence to substantiate this link.


Author(s):  
Roy S Latha ◽  
Gayathri Devi D R

Community acquired pneumonia (CAP) remains a common and serious illness despite availability of potent anti-microbials and effective vaccine. Two types of CAP are commonly recognised - typical and atypical. Typical pneumonia is usually caused by bacteria such as Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catharralis, whereas, atypical pneumonia can be caused by Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneuomophila. Mycoplasma pneumoniae is found to be the most common cause of CAP among atypical pathogens and is called “Walking pneumonia”. It is a common atypical respiratory pathogen that produces diseases of varied severity ranging from mild upper respiratory tract infection to severe atypical pneumonia and is also responsible for producing a wide spectrum of non-pulmonary manifestations like neurological, hepatic, cardiac diseases, hemolytic anemia, polyarthritis and erythema multiforme which occur in as many as 25% of infected persons. As it lacks cell wall they are resistant to β lactam antibiotics, hence accurate and rapid diagnosis of M. pneumoniae infections is critical to initiate appropriate antibiotic treatment. Identification of M pneumoniae allows narrowing of initial empirical regimen which decreases antibiotic selection pressure and may lessen the risk of resistance. In view of this present study will be conducted in a tertiary care hospital for identification of M pneumoniae in cases of CAP by Polymerase chain reaction (PCR). 1. To detect proportion of Mycoplasma Pneumoniae among cases of CAP. 2. Detection of 16SrRNA Mycoplasma pneumoniae by PCR.Clinico-radiologically diagnosed 92 CAP patients were included in the study. Out of which 15 cases were caused by typical CAP pathogens like Streptococcus species, K.pneumoniae & M.tuberculosis. Samples (Sputum Bronchoalveolar lavages) from 77 suspected cases of atypical pneumonia are inoculated on PPLO broth (Difco) followed by identification of genus specific 16S rRNA Mycoplasma pneumoniae using PCR. PCR was found to be positive in 9 (11.68%) out of 77 CAP patients. PCR was found to be positive in 9 (11.68%) out of 77 CAP patients. Detection of M.pneumoniae is essential for prompt diagnosis and start of empirical therapy, thereby reducing antibiotic selection pressure.


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