scholarly journals Challenging multidrug-resistant urinary tract bacterial isolates via bio-inspired synthesis of silver nanoparticles using the inflorescence extracts of Tridax procumbens

2020 ◽  
Vol 32 (7) ◽  
pp. 3145-3152
Author(s):  
Mysoon M. Al-Ansari ◽  
P. Dhasarathan ◽  
A.J.A. Ranjitsingh ◽  
Latifah A. Al-Humaid
2020 ◽  
Vol 50 (11) ◽  
pp. 1150-1156
Author(s):  
Jogender Tanwar ◽  
Madhu Sharma ◽  
Aparna Parmar ◽  
Nimisha Tehri ◽  
Neelam Verma ◽  
...  

2022 ◽  
Author(s):  
Stephen Oloninefa ◽  
Abalaka Moses Enemaduku ◽  
Daniyan Safiya Yahaya ◽  
Mann Abdullahi

The menace of drug resistance, bioavailability and drug delivery to the target sites has motivated researchers to search for new antimicrobial agents from medicinal plants and subsequently use them for the biosynthesis of silver nanoparticles for effective killing of bacteria challenging to kill using crude extracts. The biosynthesis of silver nanoparticles was done using aqueous extract (AQE) of E<i>uphorbia heterophylla</i>, while characterization and the killing rate of conjugated silver nanoparticles (CA<sub>g</sub>NP<sub>s</sub>) were carried out using standard methods. The maximum wavelength obtained for CA<sub>g</sub>NP<sub>s</sub> was 410.33 nm, while the size distribution was 237.8 d.nm. The Fourier Transform Infra-Red result showed O-H (3308.94 cm<sup>-1</sup>), which is responsible for stabilising and reducing silver ions, while the Transmission Electron Microscopy revealed the presence of monodispersed spherical shapes CA<sub>g</sub>NP<sub>s</sub>. The Energy Dispersive Spectroscopy confirmed the presence of silver. There were reductions in the clinical bacterial isolates exposed to CA<sub>g</sub>NP<sub>s</sub> as the exposure time increased. <i>Escherichia coli</i> was killed between 6-7 h while<i> Salmonella typhimurium</i> was killed at the seven has the value of 0.00 log<sub>10</sub> CFU/ml was recorded respectively. However, there were increments in the populations of clinical bacterial isolates in control as the time of exposure increased. Therefore, the study suggests that the CA<sub>g</sub>NP<sub>s</sub> exhibit intense antimicrobial activity and the potential to be developed as an alternative agent to treat bacterial infections, curb multidrug-resistant bacterial infection, and promote speedy drug delivery to the target sites.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yamirot Merga Duffa ◽  
Kumera Terfa Kitila ◽  
Dereje Mamuye Gebretsadik ◽  
Adane Bitew

Background. Urinary tract infection (UTI) is considered as the most common bacterial infection seen among the pediatric patients. Objective. This study was carried out in order to determine the prevalence of urinary tract infection in pediatric patients, identify bacterial uropathogens responsible for the infection, and study the antibiotic sensitivity patterns of bacterial isolates. Materials and Methods. A cross-sectional study designed and conducted from January to April 2014. Clean-voided midstream urine specimens were obtained from 384 pediatric patients less than or equal to 15 years in sterile universal bottles. Urine collected from each patient was inoculated onto CLED and blood agar plates using a calibrated inoculating loop with a capacity of 0.001 ml. Inoculated plates were incubated for 24–48 hours at 37°C at inverted position aerobically. Bacterial isolates were indentified and characterized by Gram stain and by using an array of standard routine biochemical tests. The antimicrobial susceptibility test was carried out by using the Kirby–Bauer disc diffusion method. Frequency distribution tables were used to describe the findings. Logistical regression was also used to estimate crude odds ratio (COR) with 95% confidence interval (CI) of positive responses to the different variables, and P values less than 0.05 were taken as statistically significant. Result. In this study, a total of 384 patients (199 males and 185 females) aged less than or equal to 15 years from whom urine samples were collected were enrolled. Of these patients, 61 (15.9%) had significant bacteriuria. Of the 185 females, 36 (19.5%) came up with positive cultures, while 25 (12.6%) of the 199 males had significant bacteriuria, and the largest number of study subjects were below the age of 3 years, and the largest positive culture was obtained from this age group, accounting for 35 (57.4%.) out of 61 positive cultures. Bacterial species belonging to six genera were isolated and identified from 61 positive cultures, and the genera were Escherichia, Klebsiella, Staphylococcus, Proteus, Acinetobacter, and Enterococcus. E. coli was isolated in 28 cases (49.5 %), followed by Klebsiella spp. in 17 cases (27.9%), Staphylococcus spp. in 5 patients (8.2%.) (S. aureus in one and coagulase-negative staphylococci in 4 cases), Enterococcus in 7 cases (11.5%), Proteus spp. in 3 cases (4.9%), and Acinetobacter in one case (1.6%). Of the bacterial isolates, E. coli was found out to be the most common pathogen followed by Klebsiella spp. Furthermore, E. coli and Klebsiella spp. were the most common pathogens in female patients accounting for 71.4% and 64.7%, respectively. Regarding susceptibility tests, E. coli and Klebsiella spp. were not 100% susceptible to any of the 11 antibiotics tested. Acinetobacter spp. had 100% resistance to three antibiotics: gentamicin (GN), trimethoprim-sulfamethoxazole (SXM), and augmentin (AMP). But they were 100% susceptible to ciprofloxacin (CIP), cefuroxime (CXM), norfloxacin (NOR), and ceftazidime (CAZ). On the contrary, Proteus spp. was 100% sensitive to all drugs except to nitrofurantoin. Species of Enterococcus had resistance of 71.4% to chloramphenicol (C) and 85.7% to both SXM and erythromycin. S. aureus was 100% susceptible to almost all drugs, while coagulase-negative staphylococci were not as susceptible as S. aureus. Multidrug resistance to two or more drugs was observed in 73.7% of the bacterial isolates. Conclusion. This study determined the prevalence of urinary tract infection in pediatric patients and highlighted the major bacterial uropathogens involved in UTI for the first time in the country. Furthermore, bacterial pathogen species and their frequency was consistent with the usually reported pattern, with E. coli being the most common organism isolated in cases of urinary tract infections followed by Klebsiella spp. Most of the bacterial isolates were multidrug resistant, and it is therefore suggested that appropriate antimicrobials should be administered to reduce the risk of multidrug resistant organisms developing and avert ineffectiveness of antibiotics. This condition indicates that antibiotic selection should be based on knowledge of the local prevalence of bacterial organisms and antibiotic sensitivities rather than empirical treatment. The present study indicated that ciprofloxacin (CIP), ceftazidime (CAZ), cefotaxime (CTX), cefuroxime (CXM), clindamycin (DA), and ceftriaxone (CRO) were the best antibiotics for the treatment of Gram-negative and Gram-positive bacterial uropathogens, respectively, in the study area relatively.


2018 ◽  
Vol 23 (1) ◽  
pp. 39-42
Author(s):  
Nisha Regmi ◽  
Sonali Kafle ◽  
Rabin Paudyal

A frequent and consistent evaluation of the prevalence, etiologic agents and predisposing factors of urinary tract infection (UTI) is necessary in developing country like Nepal to reduce its severe consequences. A regular and routine monitoring of multidrug resistant (MDR) clinical isolates is essential in laboratory practice. Five hundred and ninety one mid stream urine samples were collected from Bharosa Hospital of Kathmandu and a semi-quantitative method was used to determine the frequency of MDR uropathogens in the urine samples. Isolation, identification and antimicrobial susceptibility of isolated bacteria were done by standard microbiological procedure. From the total samples, 161 samples were found to be positive for UTI (27.24 %). Among these bacterial isolates, 57.14 % were found to be MDR. Nitrofurantoin, amikacin and ceftriaxone were found to be the most effective antibiotics against uropathogens.


Author(s):  
Alessandra Tammy Hayakawa Ito de Sousa ◽  
Marco Túlio dos Santos Costa ◽  
Herica Makino ◽  
Stéfhano Luis Cândido ◽  
Isabela de Godoy Menezes ◽  
...  

Author(s):  
Md. Abdullah Al Masud ◽  
Hamid Shaikh ◽  
Md. Shamsul Alam ◽  
M. Minnatul Karim ◽  
M. Abdul Momin ◽  
...  

Abstract Background The green synthesis strategy of metallic nanoparticles (NPs) has become popular due to being environmentally friendly. Stable silver nanoparticles (AgNPs) have been synthesized by natural products such as starch, soy protein, various extract of leaves, barks, and roots functioning both as reducing and stabilizing agents. Likewise, silk sericin (SS) is a globular protein discarded in the silk factory might be used for NP synthesis. In this research, we focus on the green synthesis and stabilization of AgNPs by SS as well as assessment of their antibacterial activities against some drug-resistant pathogen. Results SS was extracted from Bombyx mori silkworm cocoons in an aqueous medium. 17 w/w% of dry sericin powder with respect to the cocoon’s weight was obtained by freeze-drying. Furthermore, AgNPs conjugated to sericin, i.e., SS-capped silver nanoparticles (SS-AgNPs) were synthesized by easy, cost-effective, and environment-friendly methods. The synthesized SS-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction measurement. It has been found from the absorbance of UV-visible spectroscopy that a higher percent of SS-AgNPs was obtained at a higher concentration of silver nitrate solution. FTIR-ATR spectra showed that the carboxylate groups obtained from silk sericin act as a reducing agent for the synthesis of silver nanoparticles, while NH2+ and COO− act as a stabilizer of AgNPs. The X-ray diffractogram of SS-AgNPs was quite different from AgNO3 and sericin due to a change in the crystal structure. The diameter of AgNPs was around 20–70 nm observed using TEM. The synthesized SS-AgNPs exhibited strong antibacterial activity against multidrug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 20μg/mL. Conclusions This study encourages the use of Bombyx mori for the ecofriendly synthesis of SS-AgNPs to control multidrug-resistant microorganisms.


2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.


Sign in / Sign up

Export Citation Format

Share Document