scholarly journals Susceptibility of Virulent Yersinia pestis Bacteria to Predator Bacteria in the Lungs of Mice

2018 ◽  
Vol 7 (1) ◽  
pp. 2 ◽  
Author(s):  
Riccardo Russo ◽  
Irina Kolesnikova ◽  
Thomas Kim ◽  
Shilpi Gupta ◽  
Androulla Pericleous ◽  
...  

Multi-drug resistant bacterial infections are a serious threat to global public health. Changes in treatment modalities and prudent use of antibiotics can assist in reducing the threat, but new approaches are also required for untreatable cases. The use of predatory bacteria, such as Bdellovibrio bacteriovorus, is among the novel approaches being considered as possible therapeutics for antibiotic resistant and/or unidentified bacterial infections. Previous studies have examined the feasibility of using predatory bacteria to reduce colony-forming units (CFUs) in the lungs of rats exposed to lethal doses of Klebsiella pneumoniae; here we apply the approach to the Tier 1 select agent Yersinia pestis, and show that three doses of B. bacteriovorus introduced every six hours reduces the number of CFUs of Y. pestis in the lungs of inoculated mice by 86% after 24 h of infection. These experiments further demonstrate that predatory bacteria may serve to combat Gram negative bacterial infections, including those considered potential bioweapon agents, in the future.

2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.


2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.


Author(s):  
Maheswaran Easwaran ◽  
Nageshwari Raja ◽  
Juhee Ahn ◽  
Hemalatha Karuppiah ◽  
Hyun Jin Shin

The antimicrobial resistance has significantly risen in last few decades as a result of too much usage of antibiotics. In the case of failure of drug therapy, the multidrug resistance has become a serious issue in a clinical and food sectors. The rapid emergence of antibiotic resistance has become a great concern for public health worldwide. Therefore, the novel approaches of nano-biomaterials (NBM) and bacteriophage (phage) have received a new attention as an alternative treatment for antibiotic-resistant bacterial infections. Moreover, the advanced molecular biology and genetic engineering have been successfully applied for the rapid detection and control of multidrug resistant pathogenic strains. This chapter specifically summarizes the prevalence of common as well as under-researched antimicrobial resistance of bacterial pathogens and the application of nano-biomaterials and bacteriophage to fight against antimicrobial resistance. Ultimately, the synergistic approach will be a highly promising prospect to threat of antimicrobial resistance.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 469-471 ◽  
Author(s):  
Bhagyashri Vijay Chaudhari ◽  
Priya P. Chawle

“A lesson learned the hard way is a lesson learned for a lifetime.” Every bad situation hurts; however, it sure does teach us something a lesson. In the same manner of a new lesson for Human lifetime, history is observing 'The Novel COVID-19 ’, a very horrible and strange situation created due to fighting with a microscopic enemy. WHO on 11 February 2020 has announced a name for new disease as - 19 and has declared as a global public health emergency and subsequently as pandemic because of its widespread. This began as an outbreak in December 2019, with its in Wuhan, the People Republic of China has emerged as a public health emergency of international concern. is the group of a virus with non-segmented, single-stranded and positive RNA genome. This bad situation of pandemic creates new scenes in the life of people in a different manner, which will be going to be life lessons for them. Such lessons should be kept in mind for the safety of living beings and many more things. In this narrative review article, reference was taken from a different article published in various databases which include the view of different authors and writers on the "Lessons to be from Corona".


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 977-982
Author(s):  
Mohamed J. Saadh ◽  
Bashar Haj Rashid M ◽  
Roa’a Matar ◽  
Sajeda Riyad Aldibs ◽  
Hala Sbaih ◽  
...  

SARS-COV2 virus causes Coronavirus disease (COVID-19) and represents the causative agent of a potentially fatal disease that is of great global public health concern. The novel coronavirus (2019) was discovered in 2019 in Wuhan, the market of the wet animal, China with viral pneumonia cases and is life-threatening. Today, WHO announces COVID-19 outbreak as a pandemic. COVID-19 is likely to be zoonotic. It is transmitted from bats as intermediary animals to human. Also, the virus is transmitted from human to human who is in close contact with others. The computerized tomographic chest scan is usually abnormal even in those with no symptoms or mild disease. Treatment is nearly supportive; the role of antiviral agents is yet to be established. The SARS-COV2 virus spreads faster than its two ancestors, the SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), but has lower fatality. In this article, we aimed to summarize the transmission, symptoms, pathogenesis, diagnosis, treatment, and vaccine to control the spread of this fatal disease.


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 571
Author(s):  
Nicole Zacharias ◽  
Iris Löckener ◽  
Sarah M. Essert ◽  
Esther Sib ◽  
Gabriele Bierbaum ◽  
...  

Bacterial infections have been treated effectively by antibiotics since the discovery of penicillin in 1928. A worldwide increase in the use of antibiotics led to the emergence of antibiotic resistant strains in almost all bacterial pathogens, which complicates the treatment of infectious diseases. Antibiotic-resistant bacteria play an important role in increasing the risk associated with the usage of surface waters (e.g., irrigation, recreation) and the spread of the resistance genes. Many studies show that important pathogenic antibiotic-resistant bacteria can enter the environment by the discharge of sewage treatment plants and combined sewage overflow events. Mussels have successfully been used as bio-indicators of heavy metals, chemicals and parasites; they may also be efficient bio-indicators for viruses and bacteria. In this study an influence of the discharge of a sewage treatment plant could be shown in regard to the presence of E. coli in higher concentrations in the mussels downstream the treatment plant. Antibiotic-resistant bacteria, resistant against one or two classes of antibiotics and relevance for human health could be detected in the mussels at different sampling sites of the river Rhine. No multidrug-resistant bacteria could be isolated from the mussels, although they were found in samples of the surrounding water body.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 650
Author(s):  
Kylen E. Ridyard ◽  
Joerg Overhage

The rise in antimicrobial resistant bacteria threatens the current methods utilized to treat bacterial infections. The development of novel therapeutic agents is crucial in avoiding a post-antibiotic era and the associated deaths from antibiotic resistant pathogens. The human antimicrobial peptide LL-37 has been considered as a potential alternative to conventional antibiotics as it displays broad spectrum antibacterial and anti-biofilm activities as well as immunomodulatory functions. While LL-37 has shown promising results, it has yet to receive regulatory approval as a peptide antibiotic. Despite the strong antimicrobial properties, LL-37 has several limitations including high cost, lower activity in physiological environments, susceptibility to proteolytic degradation, and high toxicity to human cells. This review will discuss the challenges associated with making LL-37 into a viable antibiotic treatment option, with a focus on antimicrobial resistance and cross-resistance as well as adaptive responses to sub-inhibitory concentrations of the peptide. The possible methods to overcome these challenges, including immobilization techniques, LL-37 delivery systems, the development of LL-37 derivatives, and synergistic combinations will also be considered. Herein, we describe how combination therapy and structural modifications to the sequence, helicity, hydrophobicity, charge, and configuration of LL-37 could optimize the antimicrobial and anti-biofilm activities of LL-37 for future clinical use.


2020 ◽  
Vol 8 ◽  
pp. 232470962095010 ◽  
Author(s):  
Rawan Amir ◽  
Asim Kichloo ◽  
Jagmeet Singh ◽  
Ravinder Bhanot ◽  
Michael Aljadah ◽  
...  

Hemophagocytic lymphohistocytosis (HLH) is a hyperinflammatory syndrome characterized by fever, hepatosplenomegaly, and pancytopenia. It may be associated with genetic mutations or viral/bacterial infections, most commonly Epstein-Barr virus (EBV) and cytomegalovirus. As for the novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), also known as COVID-19 (coronavirus disease-2019), the cytokine storm it triggers can theoretically lead to syndromes similar to HLH. In this article, we report a case of a 28-year-old female who presented with high-grade fevers, found to have both SARS-CoV-2 and EBV infections, and eventually began to show signs of early HLH. To our knowledge, this is the first case reported in literature that raises the possibility of SARS-CoV-2–related HLH development.


2011 ◽  
Vol 19 (03) ◽  
pp. 505-520
Author(s):  
HAI-FENG HUO ◽  
JUN LI ◽  
YU-NING LI

Infection caused by antibiotic-resistant pathogens is one of global public health problems. Many factors contribute to the emergence and spread of these pathogens. A model which describes the transmission dynamics of susceptible and resistant bacteria in a pregnant woman and the fetus is presented. Detailed qualitative analysis about positivity, boundedness, global stability and uniform persistence of the model is carried out. Numerical simulation and sensitivity analysis show that antibiotic input has potential impact for neonatal drug resistance. Our results show that the resistant bacteria in baby mainly come from antibiotics which are wrongly-used during gestational period, or foods containing antibiotic residues.


2021 ◽  
Author(s):  
Samilla Rezende ◽  
karen k.n. oshiro ◽  
Nelson Junior ◽  
Octavio L. Franco ◽  
Marlon Henrique Cardoso

Antimicrobial peptides (AMPs) are pinpointed as promising molecules against antibiotic-resistant bacterial infections. Nevertheless, there is a discrepancy between the AMP sequences generated and the tangible outcomes in clinical trials. AMPs’...


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