Surface Ligand Density of Antibiotic-Nanoparticle Conjugates Enhances Target Avidity and Membrane Permeabilization of Vancomycin-Resistant Bacteria

2016 ◽  
Vol 28 (2) ◽  
pp. 353-361 ◽  
Author(s):  
Marwa M. Hassan ◽  
Andrea Ranzoni ◽  
Wanida Phetsang ◽  
Mark A. T. Blaskovich ◽  
Matthew A. Cooper
Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 466
Author(s):  
Herbert Galler ◽  
Josefa Luxner ◽  
Christian Petternel ◽  
Franz F. Reinthaler ◽  
Juliana Habib ◽  
...  

In recent years, antibiotic-resistant bacteria with an impact on human health, such as extended spectrum β-lactamase (ESBL)-containing Enterobacteriaceae, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE), have become more common in food. This is due to the use of antibiotics in animal husbandry, which leads to the promotion of antibiotic resistance and thus also makes food a source of such resistant bacteria. Most studies dealing with this issue usually focus on the animals or processed food products to examine the antibiotic resistant bacteria. This study investigated the intestine as another main habitat besides the skin for multiresistant bacteria. For this purpose, faeces samples were taken directly from the intestines of swine (n = 71) and broiler (n = 100) during the slaughter process and analysed. All samples were from animals fed in Austria and slaughtered in Austrian slaughterhouses for food production. The samples were examined for the presence of ESBL-producing Enterobacteriaceae, MRSA, MRCoNS and VRE. The resistance genes of the isolated bacteria were detected and sequenced by PCR. Phenotypic ESBL-producing Escherichia coli could be isolated in 10% of broiler casings (10 out of 100) and 43.6% of swine casings (31 out of 71). In line with previous studies, the results of this study showed that CTX-M-1 was the dominant ESBL produced by E. coli from swine (n = 25, 83.3%) and SHV-12 from broilers (n = 13, 81.3%). Overall, the frequency of positive samples with multidrug-resistant bacteria was lower than in most comparable studies focusing on meat products.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2888 ◽  
Author(s):  
Buthaina Jubeh ◽  
Zeinab Breijyeh ◽  
Rafik Karaman

The discovery of antibiotics has created a turning point in medical interventions to pathogenic infections, but unfortunately, each discovery was consistently followed by the emergence of resistance. The rise of multidrug-resistant bacteria has generated a great challenge to treat infections caused by bacteria with the available antibiotics. Today, research is active in finding new treatments for multidrug-resistant pathogens. In a step to guide the efforts, the WHO has published a list of the most dangerous bacteria that are resistant to current treatments and requires the development of new antibiotics for combating the resistance. Among the list are various Gram-positive bacteria that are responsible for serious healthcare and community-associated infections. Methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and drug-resistant Streptococcus pneumoniae are of particular concern. The resistance of bacteria is an evolving phenomenon that arises from genetic mutations and/or acquired genomes. Thus, antimicrobial resistance demands continuous efforts to create strategies to combat this problem and optimize the use of antibiotics. This article aims to provide a review of the most critical resistant Gram-positive bacterial pathogens, their mechanisms of resistance, and the new treatments and approaches reported to circumvent this problem.


2019 ◽  
Vol 20 (6) ◽  
pp. 1255 ◽  
Author(s):  
Ana Monserrat-Martinez ◽  
Yann Gambin ◽  
Emma Sierecki

Since their discovery in the early 20th century, antibiotics have been used as the primary weapon against bacterial infections. Due to their prophylactic effect, they are also used as part of the cocktail of drugs given to treat complex diseases such as cancer or during surgery, in order to prevent infection. This has resulted in a decrease of mortality from infectious diseases and an increase in life expectancy in the last 100 years. However, as a consequence of administering antibiotics broadly to the population and sometimes misusing them, antibiotic-resistant bacteria have appeared. The emergence of resistant strains is a global health threat to humanity. Highly-resistant bacteria like Staphylococcus aureus (methicillin-resistant) or Enterococcus faecium (vancomycin-resistant) have led to complications in intensive care units, increasing medical costs and putting patient lives at risk. The appearance of these resistant strains together with the difficulty in finding new antimicrobials has alarmed the scientific community. Most of the strategies currently employed to develop new antibiotics point towards novel approaches for drug design based on prodrugs or rational design of new molecules. However, targeting crucial bacterial processes by these means will keep creating evolutionary pressure towards drug resistance. In this review, we discuss antibiotic resistance and new options for antibiotic discovery, focusing in particular on new alternatives aiming to disarm the bacteria or empower the host to avoid disease onset.


2020 ◽  
Vol 8 (10) ◽  
pp. 1487
Author(s):  
Marta Aires-de-Sousa ◽  
Claudine Fournier ◽  
Elizeth Lopes ◽  
Hermínia de Lencastre ◽  
Patrice Nordmann ◽  
...  

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 85 ◽  
Author(s):  
Hercules Sakkas ◽  
Petros Bozidis ◽  
Afrodite Ilia ◽  
George Mpekoulis ◽  
Chrissanthy Papadopoulou

During a six-month period (October 2017–March 2018), the prevalence and susceptibility of important pathogenic bacteria isolated from 12 hospital raw sewage samples in North Western Greece was investigated. The samples were analyzed for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum beta-lactamase (ESBL) producing Escherichia coli, carbapenemase-producing Klebsiella pneumoniae (CKP), and multidrug-resistant Pseudomonas aeruginosa. Antimicrobial susceptibility testing was performed using the agar diffusion method according to the recommendations of the Clinical and Laboratory Standards Institute. The diversity of carbapenemases harboring K. pneumoniae was examined by two phenotyping screening methods (modified Hodge test and combined disk test), a new immunochromatographic rapid assay (RESIST-4 O.K.N.V.) and a polymerase chain reaction (PCR). The results demonstrated the prevalence of MRSA, vancomycin-resistant Staphylococcus aureus (VRSA), VRE, and CKP in the examined hospital raw sewage samples. In addition, the aforementioned methods which are currently used in clinical laboratories for the rapid identification and detection of resistant bacteria and genes, performed sufficiently to provide reliable results in terms of accuracy and efficiency.


Soft Matter ◽  
2010 ◽  
Vol 6 (7) ◽  
pp. 1513 ◽  
Author(s):  
Masafumi Fukuto ◽  
Suntao Wang ◽  
Matthew A. Lohr ◽  
Sumit Kewalramani ◽  
Lin Yang

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