scholarly journals Recent Advances in the Surface Functionalization of Nanomaterials for Antimicrobial Applications

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6932
Author(s):  
Shahin Shah Khan ◽  
Irfan Ullah ◽  
Sadeeq Ullah ◽  
Ruipeng An ◽  
Haijun Xu ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Near Infrared ◽  
Biomedical Application ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Pathogenic Microorganisms ◽  
Infrared Irradiation ◽  
Oxygen Production ◽  
E Coli ◽  
High Absorption

Innovations in nanotechnology have had an immense impact on medicine, such as in drug delivery, tissue engineering, and medical devices that combat different pathogens. The pathogens that may cause biofilm-associated nosocomial diseases are multidrug-resistant (MDR) bacteria, such as Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), including both Gram-positive and Gram-negative bacterial species. About 65–80% of infections are caused by biofilm-associated pathogens creating a move in the international community toward developing antimicrobial therapies to eliminate such pathogenic infections. Several nanomaterials (NMs) have been discovered and significantly employed in various antipathogenic therapies. These NMs have unique properties of singlet oxygen production, high absorption of near-infrared irradiation, and reasonable conversion of light to heat. In this review, functionalized NPs that combat different pathogenic infections are introduced. This review highlights NMs that combat infections caused by multidrug-resistant (MDR) and other pathogenic microorganisms. It also highlights the biomedical application of NPs with regard to antipathogenic activities.

scholarly journals Escherichia coli Clonobiome: Assessing the Strain Diversity in Feces and Urine by Deep Amplicon Sequencing

2019 ◽  
Vol 85 (23) ◽  
Author(s):  
Sofiya G. Shevchenko ◽  
Matthew Radey ◽  
Veronika Tchesnokova ◽  
Dagmara Kisiela ◽  
Evgeni V. Sokurenko
Keyword(s):  
Bacterial Species ◽  
Clonal Diversity ◽  
Amplicon Sequencing ◽  
Multidrug Resistant ◽  
Full Understanding ◽  
Highly Pathogenic ◽  
Content Type ◽  
E Coli ◽  
Strain Diversity ◽  
Healthy Carriers

ABSTRACT While microbiome studies have focused on diversity at the species level or higher, bacterial species in microbiomes are represented by different, often multiple, strains. These strains could be clonally and phenotypically very different, making assessment of strain content vital to a full understanding of microbiome function. This is especially important with respect to antibiotic-resistant strains, the clonal spread of which may be dependent on competition between them and susceptible strains from the same species. The pandemic, multidrug-resistant, and highly pathogenic Escherichia coli subclone ST131-H30 (H30) is of special interest, as it has already been found persisting in the gut and bladder in healthy people. In order to rapidly assess E. coli clonal diversity, we developed a novel method based on deep sequencing of two loci used for sequence typing, along with an algorithm for analysis of the resulting data. Using this method, we assessed fecal and urinary samples from healthy women carrying H30 and were able to uncover considerable diversity, including strains with frequencies at <1% of the E. coli population. We also found that, even in the absence of antibiotic use, H30 could completely dominate the gut and, especially, urine of healthy carriers. Our study offers a novel tool for assessing a species’ clonal diversity (clonobiome) within the microbiome, which could be useful in studying the population structure and dynamics of multidrug-resistant and/or highly pathogenic strains in their natural environments. IMPORTANCE Bacterial species in the microbiome are often represented by multiple genetically and phenotypically different strains, making insight into subspecies diversity critical to a full understanding of the microbiome, especially with respect to opportunistic pathogens. However, methods allowing efficient high-throughput clonal typing are not currently available. This study combines a conventional E. coli typing method with deep amplicon sequencing to allow analysis of many samples concurrently. While our method was developed for E. coli, it may be adapted for other species, allowing microbiome researchers to assess clonal strain diversity in natural samples. Since assessment of subspecies diversity is particularly important for understanding the spread of antibiotic resistance, we applied our method to the study of a pandemic multidrug-resistant E. coli clone. The results we present suggest that this clone could be highly competitive in healthy carriers and that the mechanisms of colonization by such clones need to be studied.

scholarly journals Near-Infrared Spectroscopy Evaluations for the Differentiation of Carbapenem-Resistant from Susceptible Enterobacteriaceae Strains

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 736
Author(s):  
Bushra Alharbi ◽  
Maggy Sikulu-Lord ◽  
Anton Lord ◽  
Hosam M. Zowawi ◽  
Ella Trembizki
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Predictive Accuracy ◽  
Bacterial Species ◽  
Carbapenem Resistance ◽  
Accurate Identification ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Global Threat

Antimicrobial Resistance (AMR) caused by Carbapenem-Resistant Enterobacteriaceae (CRE) is a global threat. Accurate identification of these bacterial species with associated AMR is critical for their management. While highly accurate methods to detect CRE are available, they are costly, timely and require expert skills, making their application infeasible in low-resource settings. Here, we investigated the potential of Near-Infrared Spectroscopy (NIRS) for a range of applications: (i) the detection and differentiation of isolates of two pathogenic Enterobacteriaceae species, Klebsiella pneumoniae and Escherichia coli, and (ii) the differentiation of carbapenem resistant and susceptible K. pneumoniae. NIRS has successfully differentiated between K. pneumoniae and E. coli isolates with a predictive accuracy of 89.04% (95% CI; 88.7–89.4%). K. pneumoniae isolates harbouring carbapenem-resistance determinants were differentiated from susceptible K. pneumoniae strains with an accuracy of 85% (95% CI; 84.2–86.1%). To our knowledge, this is the largest proof of concept demonstration for the utility and feasibility of NIRS to rapidly differentiate between K. pneumoniae and E. coli as well as carbapenem-resistant K. pneumoniae from susceptible strains.

scholarly journals The bactericidal effect of continuous wave laser with strongly absorbing coating at the fiber tip

2018 ◽  
Vol 11 (05) ◽  
pp. 1850029
Author(s):  
Vadim Elagin ◽  
Anton Smirnov ◽  
Vladimir Yusupov ◽  
Alexey Kirillov ◽  
Nadezhda Ignatova ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Large Scale ◽  
Near Infrared ◽  
Continuous Wave ◽  
Bacterial Species ◽  
Bactericidal Effect ◽  
Bacterial Suspension ◽  
Main Role ◽  
Continuous Wave Laser ◽  
E Coli

The bactericidal effect of laser radiation with a quartz fiber-based transmission system with a strong absorption coating converter against bacteria associated with urological stones has been studied. Gram-negative rod Escherichia coli and the Gram-positive coccus Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium were used in this study. Each bacterial species was treated by continuous-wave near infrared laser coupled with bare fiber tip or strongly absorption coating fiber tip. After treatment, the temperature of bacterial suspension was measured. In addition, the temperature distribution was analyzed. It has been shown that using laser with a strongly absorption coating fiber tip results in significant bactericidal effect. The decrease of the amount of E. coli and S. epidermidis was 100% after treatment with an output power of 6[Formula: see text]W of radiation at a wavelength of 0.97[Formula: see text][Formula: see text]m for 40[Formula: see text]s. Number of S. aureus and Ent. faecium colony-forming unit was reduced to 70% after same exposure. The peak temperature of bacterial suspension was [Formula: see text]C after treatment by laser with a strongly absorption coating fiber tip. Laser with a strongly absorption coating fiber tip provides large-scale hydrodynamic flows directed away from the fiber tip. The laser with a strongly absorption coating fiber tip has bactericidal effect. The main role is associated with the effect of high temperature, which, in the form of flow in a liquid medium, affects bacteria.

Biofilm Formation by Multidrug-Resistant Salmonella enterica Serotype Typhimurium Phage Type DT104 and Other Pathogens

2007 ◽  
Vol 70 (1) ◽  
pp. 22-29 ◽  
Author(s):  
SHIN-HEE KIM ◽  
CHENG-I WEI
Keyword(s):  
Stainless Steel ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Bacterial Species ◽  
Phage Type ◽  
Meat Products ◽  
Multidrug Resistant ◽  
E Coli ◽  
Retail Meat ◽  
Glass Surfaces

The biofilm-forming capability of Salmonella enterica serotypes Typhimurium and Heidelberg, Pseudomonas aeruginosa, Listeria monocytogenes, Escherichia coli O157:H7, Klebsiella pneumoniae, and Acinetobacter baumannii isolated from humans, animal farms, and retail meat products was evaluated by using a microplate assay. The tested bacterial species showed interstrain variation in their capabilities to form biofilms. Strong biofilm-forming strains of S. enterica serotypes, E. coli O157: H7, P. aeruginosa, K. pneumoniae, and A. baumannii were resistant to at least four of the tested antibiotics. To understand their potential in forming biofilms in food-processing environments, the strong biofilm formers grown in beef, turkey, and lettuce broths were further investigated on stainless steel and glass surfaces. Among the tested strains, Salmonella Typhimurium phage type DT104 (Salmonella Typhimurium DT104) isolated from retail beef formed the strongest biofilm on stainless steel and glass in beef and turkey broths. K. pneumoniae, L. monocytogenes, and P. aeruginosa were also able to form strong biofilms on the tested surface materials. Salmonella Typhimurium DT104 developed a biofilm on stainless steel in beef and turkey broths through (i) initial attachment to the surface, (ii) formation of microcolonies, and (iii) biofilm maturation. These findings indicated that Salmonella Typhimurium DT104 along with other bacterial pathogens could be a source of cross-contamination during handling and processing of food.

scholarly journals Routine Intraoperative Bacterial Culture May Be Needed in Complicated Appendicitis

2020 ◽  
Vol 36 (3) ◽  
pp. 155-162
Author(s):  
Jung Tack Son ◽  
Gue Chun Lee ◽  
Hyung Ook Kim ◽  
Taewoon Kim ◽  
Donghyoun Lee ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Complicated Appendicitis ◽  
Resistant Bacteria ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Positive Rate ◽  
Antibiotics Susceptibility ◽  
Resistance Rates

Purpose: Choosing the appropriate antibiotic is important for treatment of complicated appendicitis. However, increasing multidrug resistant bacteria have been a serious problem for successful treatment. This study was designed to identify bacteria isolated from patients with complicated appendicitis and reveal their susceptibilities for antibiotics and their relationship with patient clinical course.Methods: This study included patients diagnosed with complicated appendicitis and examined the bacterial cultures and antimicrobial susceptibilities of the isolates. Data were retrospectively collected from medical records of Kangbuk Samsung Hospital from January 2008 to February 2018.Results: The common bacterial species cultured in complicated appendicitis were as follows: <i>Escherichia coli</i> (n=113, 48.9%), <i>Streptococcus</i> spp. (n=29, 12.6%), <i>Pseudomonas</i> spp. (n=23, 10.0%), <i>Bacteriodes</i> spp. (n=22, 9.5%), <i>Klebsiella</i> (n=11, 4.8%), and <i>Enterococcus</i> spp. (n=8, 3.5%). In antibiotics susceptibility testing, the positive rate of extended-spectrum beta lactamase (ESBL) was 9.1% (21 of 231). The resistance rate to carbapenem was 1.7% (4 of 231), while that to vancomycin was 0.4% (1 of 231). <i>E. coli</i> was 16.8% ESBL positive (19 of 113) and had 22.1% and 19.5% resistance rates to cefotaxime and ceftazidime, respectively. Inappropriate empirical antibiotic treatment (IEAT) occurred in 55 cases (31.8%) and was significantly related with organ/space surgical site infection (SSI) (7 of 55, P=0.005).Conclusion: The rate of antibiotic resistance organisms was high in community-acquired complicated appendicitis in Koreans. Additionally, IEAT in complicated appendicitis may lead to increased rates of SSI. Routine intraoperative culture in patients with complicated appendicitis may be an effective strategy for appropriate antibiotic regimen.

Detection and Identification of Bacteria in a Juice Matrix with Fourier Transform–Near Infrared Spectroscopy and Multivariate Analysis

2004 ◽  
Vol 67 (11) ◽  
pp. 2555-2559 ◽  
Author(s):  
L. E. RODRIGUEZ-SAONA ◽  
F. M. KHAMBATY ◽  
F. S. FRY ◽  
J. DUBOIS ◽  
E. M. CALVEY
Keyword(s):  
Fourier Transform ◽  
Membrane Filtration ◽  
Bacterial Contamination ◽  
Near Infrared ◽  
Bacterial Species ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Multivariate Techniques ◽  
Bacterial Cells ◽  
E Coli

The use of Fourier transform–near infrared (FT-NIR) spectroscopy combined with multivariate pattern recognition techniques was evaluated to address the need for a fast and sensitive method for the detection of bacterial contamination in liquids. The complex cellular composition of bacteria produces FT-NIR vibrational transitions (overtone and combination bands), forming the basis for identification and subtyping. A database including strains of Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus cereus, and Bacillus thuringiensis was built, with special care taken to optimize sample preparation. The bacterial cells were treated with 70% (vol/vol) ethanol to enhance safe handling of pathogenic strains and then concentrated on an aluminum oxide membrane to obtain a thin bacterial film. This simple membrane filtration procedure generated reproducible FT-NIR spectra that allowed for the rapid discrimination among closely related strains. Principal component analysis and soft independent modeling of class analogy of transformed spectra in the region 5,100 to 4,400 cm−1 were able to discriminate between bacterial species. Spectroscopic analysis of apple juices inoculated with different strains of E. coli at approximately 105 CFU/ml showed that FT-NIR spectral features are consistent with bacterial contamination and soft independent modeling of class analogy correctly predicted the identity of the contaminant as strains of E. coli. FT-NIR in conjunction with multivariate techniques can be used for the rapid and accurate evaluation of potential bacterial contamination in liquids with minimal sample manipulation, and hence limited exposure of the laboratory worker to the agents.

scholarly journals First isolation of atypical enteropathogenic Escherichia coli from geese (Anser anser domestica) and first description of atypical EPEC from turkeys and pigeons in Hungary

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
András Adorján ◽  
Ákos Thuma ◽  
László Könyves ◽  
István Tóth
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Age Groups ◽  
Multidrug Resistant ◽  
Growing Up ◽  
Anser Anser ◽  
E Coli ◽  
Atypical Epec ◽  
Chicken Farm ◽  
Backyard Chicken

Abstract Background Escherichia coli is a bacterial species widely distributed among mammals and avian species, and also a member of the normal intestinal microbiota. However, some E. coli strains of different pathotypes can cause disease in both humans and animals. Atypical enteropathogenic E. coli (aEPEC) can infect both animals and humans or influence the severity of other ongoing infections. Results In the present study, a total of 332 samples were collected from ducks, geese, turkeys, chickens, and pigeons from the Hungarian Veterinary Diagnostic Directorate, two slaughterhouses, two pigeon keepers and one backyard chicken farm. E. coli was isolated and verified from 319 samples. The isolates were screened by PCR for diarrheagenic E. coli pathotypes. Altogether seven atypical enteropathogenic E. coli (aEPEC) strains were identified: two from four-week-old dead turkeys, two from force-fed geese, and three from pigeons. No further pathotypes were identified in the collection. The atypical EPEC strains were classified phylogenetically to B1, B2, and F, and four out of the seven aEPEC isolates proved to be multidrug resistant. Serotypes of aEPEC strains were uniform collected from same farms and showed diversity between their origins with O76, O145, O109 serogroups. Conclusions This is the first report in the literature about aEPEC in goose (Anser anser domestica). Furthermore, this is the first isolation of aEPEC from turkeys and pigeons in Hungary. The uneven distribution of aEPEC in different age groups of poultry suggests that aEPEC disappears with growing up, but stress (e.g.: force-feeding) and concurrent diseases might promote its reappearance in the intestine.

scholarly journals Effects of Lipidation on a Proline-Rich Antibacterial Peptide

2021 ◽  
Vol 22 (15) ◽  
pp. 7959
Author(s):  
Federica Armas ◽  
Adriana Di Stasi ◽  
Mario Mardirossian ◽  
Antonello A. Romani ◽  
Monica Benincasa ◽  
...  
Keyword(s):  
De Novo ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
C Terminus ◽  
Proline Rich Peptide ◽  
Conventional Antibiotics

The emergence of multidrug-resistant bacteria is a worldwide health problem. Antimicrobial peptides have been recognized as potential alternatives to conventional antibiotics, but still require optimization. The proline-rich antimicrobial peptide Bac7(1-16) is active against only a limited number of Gram-negative bacteria. It kills bacteria by inhibiting protein synthesis after its internalization, which is mainly supported by the bacterial transporter SbmA. In this study, we tested two different lipidated forms of Bac7(1-16) with the aim of extending its activity against those bacterial species that lack SbmA. We linked a C12-alkyl chain or an ultrashort cationic lipopeptide Lp-I to the C-terminus of Bac7(1-16). Both the lipidated Bac-C12 and Bac-Lp-I forms acquired activity at low micromolar MIC values against several Gram-positive and Gram-negative bacteria. Moreover, unlike Bac7(1-16), Bac-C12, and Bac-Lp-I did not select resistant mutants in E. coli after 14 times of exposure to sub-MIC concentrations of the respective peptide. We demonstrated that the extended spectrum of activity and absence of de novo resistance are likely related to the acquired capability of the peptides to permeabilize cell membranes. These results indicate that C-terminal lipidation of a short proline-rich peptide profoundly alters its function and mode of action and provides useful insights into the design of novel broad-spectrum antibacterial agents.

scholarly journals Antimicrobial effects of syndiotactic polypeptides

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prakash Kishore Hazam ◽  
Chimanjita Phukan ◽  
R. Akhil ◽  
Anjali Singh ◽  
Vibin Ramakrishnan
Keyword(s):  
Amino Acids ◽  
Design Space ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Model Systems ◽  
Dynamics Simulation ◽  
Simulation Studies ◽  
Molecular Systems ◽  
E Coli ◽  
Present Design

AbstractWe present design and antibacterial studies of stereochemically diversified antimicrobial peptides against multidrug-resistant bacterial pathogens. Syndiotactic polypeptides are polymers of alternating L and D amino acids with LDLD or DLDL backbone stereochemical sequence, which can form stable gramicidin like helical conformations. We designed, synthesized and characterized eight model molecular systems with varied electrostatic fingerprints, modulated through calibrated sequence positioning. Six out of eight model systems showed very impressive antimicrobial activity against three difficult to treat bacterial species, Gentamicin resistant MRSA, E. coli and Mycobacterium. More importantly, the designed LDLD peptides were equally potent in serum, an important drawback of poly L peptide sequences due to enzyme mediated degradation and ion sensitivity. Further, we tested the activity of the designed peptides against drug-resistant clinical isolates of Staphylococcus aureus and Escherichia coli. Molecular dynamics simulation studies suggest formation of an assembly of individual peptides, preceding the membrane interaction and deformation. The activity estimates are comparable with the available peptide based antimicrobials, and are also highly specific and less toxic as per standard estimates. Incorporation of D amino-acids can significantly expand the peptide design space, which can in turn manifest in future biomaterial designs, especially antimicrobials.

scholarly journals Therapeutic effect of biosynthetic gold nanoparticles on multidrug-resistant Escherichia coli and Salmonella species isolated from ruminants

2021 ◽  
pp. 3200-3210
Author(s):  
Abeer M. Abdalhamed ◽  
Alaa A. Ghazy ◽  
Eman S. Ibrahim ◽  
Amany A. Arafa ◽  
Gamil S. G. Zeedan
Keyword(s):  
Escherichia Coli ◽  
Gold Nanoparticles ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Pathogenic Microorganisms ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
E Coli

Background and Aim: Multidrug-resistant (MDR) pathogenic microorganisms have become a global problem in ruminants as a result of the intensive use of antibiotics, causing the development of resistance among gut microbiota. The antibiotic-resistant microorganisms can be transferred from diseased animals to humans. This study aimed to determine the prevalence of MDR Escherichia coli and Salmonella spp. isolated from cattle, buffaloes, sheep, and goats suffering from respiratory signs, diarrhea, and mastitis and to screen the antibiotic sensitivity of selected isolated bacteria. It also detected antibiotic-resistance genes by polymerase chain reaction (PCR), produced green gold nanoparticles (AuNPs) using plant extracts (Artemisia herba-alba and Morus alba), and evaluated the antimicrobial activities of these biosynthesized nanoparticles on selected pathogens (E. coli and Salmonella spp.). Materials and Methods: MDR E. coli and Salmonella spp. were investigated using fecal samples (n=408), nasal swabs (n=358), and milk samples (n=227) of cattle, buffaloes, sheep, and goats with or without clinical signs, including respiratory manifestations, pneumonia, diarrhea, and mastitis, from different governorates in Egypt. E. coli and Salmonella spp. were isolated and identified on selective media, which were confirmed by biochemical reactions and PCR. Antimicrobial susceptibility testing against 10 commonly used antibiotics was performed using the Kirby-Bauer disk diffusion method. Antibiotic resistance genes blaTEM, blaSHV, blaOXA, and blaCTX-M were detected by PCR. The antibacterial effect of the biosynthesized AuNPs was evaluated by MIC and well diffusion assay. The biosynthesized AuNPs were also characterized by ultraviolet-visible spectrophotometry and transmission electron microscopy (TEM). Results: Among all fecal samples, the prevalence of E. coli was 18.4% (183/993) and that of Salmonella spp. was 16.7% (66/408), as determined by cultural and molecular tests. All isolates of E. coli and Salmonella spp. were 100% resistant to ampicillin (AM) and amoxicillin and highly resistant to cefoxitin and AM-sulbactam. The total rate of resistance genes in E. coli was 61.2% (112/183), while that in Salmonella was 63.6% (42/66) for pathogens isolated from ruminants with respiratory manifestations, pneumonia, diarrhea, and mastitis. Among the resistance genes, blaTEM had the highest prevalence rate in E. coli (25.9%, 21/81) while blaSHV had the lowest (9.8%, 8/81) in fecal swabs. AuNPs were successfully synthesized using aqueous leaf extract of A. herba-alba and M. alba as bioreducing agents. TEM analysis showed particle size of 10-42 nm for A. herba-alba and M. alba AuNPs. The biosynthesized AuNPs showed antibacterial activity against MDR E. coli and Salmonella spp. Conclusion: Rapid and accurate diagnostic methods are the cornerstone for effective treatment to reduce the risk of antimicrobial-resistant pathogenic microorganisms. This is particularly important for overcoming the increasing rate of MDR in ruminants with respiratory manifestations, pneumonia, diarrhea, and mastitis. This can be complemented by the development of AuNPs synthesized in an environmentally friendly manner AuNPs using natural plant extracts for the treatment of antibiotic-resistant microorganisms.

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