scholarly journals Tristemma hirtumand Five Other Cameroonian Edible Plants with Weak or No Antibacterial Effects Modulate the Activities of Antibiotics against Gram-Negative Multidrug-Resistant Phenotypes

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Gaëlle S. Nguenang ◽  
Armelle T. Mbaveng ◽  
Aimé G. Fankam ◽  
Hermione T. Manekeng ◽  
Paul Nayim ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Phytochemical Analysis ◽  
Edible Plants ◽  
Phytochemical Screening ◽  
Antibacterial Effects ◽  
Gram Negative ◽  
Microdilution Method ◽  
Raphia Hookeri

In order to contribute to the fight against infectious diseases, thein vitroantibacterial activity and the antibiotic-potentiating effects ofTristemma hirtumand five other Cameroonian edible plants have been evaluated against Gram-negative multidrug-resistant (MDR) phenotypes. The microdilution method was used to evaluate the bacterial susceptibility of the extracts and their combination to common antibiotics. The phytochemical screening of the extracts was carried out according to standard methods. Phytochemical analysis of the extracts revealed the presence of alkaloids, triterpenes, steroids, and polyphenols, including flavonoids in most of the tested extracts. The entire tested extracts showed moderate (512 μg/mL ≤ MIC ≤ 2048 μg/mL) to weak (MIC > 2048 μg/mL) antibacterial activities against the tested bacteria. Furthermore, extracts of leaf ofTristemma hirtumand pericarpsofRaphia hookeri(at their MIC/2 and MIC/4) strongly potentiated the activities of all antibiotics used in the study, especially those of chloramphenicol (CHL), ciprofloxacin (CIP), kanamycin (KAN), and tetracycline (TET) against 70% (7/10) to 100% (10/10) of the tested MDR bacteria, with the modulating factors ranging from 2 to 128. The results of this study suggest that extracts from leaves ofTristemma hirtumand pericarps ofRaphia hookerican be sources of plant-derived products with antibiotic modifying activity.

scholarly journals Antibacterial and Antibiotic-Potentiating Activities of Thirteen Cameroonian Edible Plants against Gram-Negative Resistant Phenotypes

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Paul Nayim ◽  
Armelle T. Mbaveng ◽  
Brice E. N. Wamba ◽  
Aimé G. Fankam ◽  
Joachim K. Dzotam ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Bark Extract ◽  
Minimal Bactericidal Concentration ◽  
Edible Plants ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Microdilution Method ◽  
Multiresistant Bacteria ◽  
Broth Microdilution Method

This work was designed to investigate the antibacterial activities of methanol extracts from thirteen Cameroonian edible plants and their antibiotic-potentiating effects against Gram-negative multidrug-resistant (MDR) phenotypes. The broth microdilution method was used to evaluate the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts, as well as their antibiotic-potentiating activities. The phytochemical screening of the extracts was carried out according to the standard methods. The results of phytochemical tests revealed the presence of sterols, polyphenols, and tannins in most of the tested extracts, with the other classes of secondary metabolites being selectively distributed. Tested extracts showed variable antibacterial activities with MIC values ranging from 64 to 1024 μg/mL. However, some extracts were significantly active against certain bacterial strains: seeds extract of Theobroma cacao (64 μg/mL) against Escherichia coli AG100Atet and Klebsiella pneumoniae K24, and the bark extract of Uapaca guineensis against E. coli ATCC 8739. The leaves extract of T. cacao displayed the best MBC values (256 μg/mL) against E. aerogenes EA27. Some tested extracts included extracts from the leaves of T. cacao and P. vulgaris, and the seeds of D. edulis and barks A. indica has selectively improved (2- to 64-fold) the antibacterial activities of some of the tested antibiotics, chloramphenicol (CHL), tetracycline (TET), kanamycin (KAN), streptomycin (STR), and erythromycin (ERY), against more than 70% of tested MDR bacteria. The findings of this work showed that tested plant extracts and particularly those from T. cacao and Phaseolus vulgaris can be used alone or in combination with conventional antibiotics in the treatment of infections involving multiresistant bacteria.

scholarly journals Phytochemical Screening and In Vitro Antibacterial Activities of Leaf Extract Acacia etbaica Schweinf Against Multidrug Resistant Enterobacteriaceae Human Pathogens

2020 ◽  
Vol 11 (3) ◽  
pp. 4857-4865
Author(s):  
Tekleweyni Tadege ◽  
Kidu Hintsa ◽  
Tesfay Weletnsae ◽  
Gopalakrishnan V K ◽  
Muthulingam M ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Phytochemical Screening ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Acacia etbaica Schweinf belongs to the family Fabaceae widely distributed in Africa and various parts of this plant such as bark, leaves, flowers and roots are widely used as a folk medicine for curing of various ailments.This study was aimed to screen the phytoconstituents and evaluate the antibacterial activity of leaf extract of A. etbaica against selected multidrug resistant Enterobacteriaceae family. Leaves of A. etbaica were extracted with petroleum ether, chloroform, acetone, and ethanol by sequential soxhlet extraction. Phytochemical screening of organic leaf extract of A.etbaica was carried out for the detection of phytoconstituents accountable for antibacterial activity. In vitro antibacterial activities of A.etbaica leaf extracts against selected Enterobacteriaceae family gram‑positive bacteria such as (B.subtilis, E.faecalis,S.aureus)and gram-negative (E. coli, K. pneumonia, V. cholera) were evaluated by agar well diffusion. The antibacterial potential of acetone and ethanol leaf extracts of A.etbaica were determined by 96 well plate broth dilution assay. Among the tested organic leaf extracts, both acetone and ethanolic leaf extract of A.etbaica showed a potentially broad spectrum of in vitro antibacterial activity against tested multiple drug resistant Enterobacteriaceae family gram-positive pathogens such as B.subtilis, E. faecalis , and S.aureus and gram-negative bacterial strains E. coli, K. Pneumonia and V. Cholera with significant MIC values. The significant antibacterial activity of both acetone and ethanolic leaf extracts of A.etbaica was due to the subsistence of secondary metabolites phytoconstituents such as flavonoids and phenolic compounds.

scholarly journals Novel Engineered Peptides of a Phage Lysin as Effective Antimicrobials against Multidrug-Resistant Acinetobacter baumannii

2016 ◽  
Vol 60 (5) ◽  
pp. 2671-2679 ◽  
Author(s):  
Mya Thandar ◽  
Rolf Lood ◽  
Benjamin Y. Winer ◽  
Douglas R. Deutsch ◽  
Chad W. Euler ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Bacterial Pathogen ◽  
Antibacterial Activities ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Gram Negative ◽  
Content Type ◽  
Human Red Blood Cells ◽  
Phage Lysin

ABSTRACTAcinetobacter baumanniiis a Gram-negative bacterial pathogen responsible for a range of nosocomial infections. The recent rise and spread of multidrug-resistantA. baumanniiclones has fueled a search for alternative therapies, including bacteriophage endolysins with potent antibacterial activities. A common feature of these lysins is the presence of a highly positively charged C-terminal domain with a likely role in promoting outer membrane penetration. In the present study, we show that the C-terminal amino acids 108 to 138 of phage lysin PlyF307, named P307, alone were sufficient to killA. baumannii(>3 logs). Furthermore, P307 could be engineered for improved activity, the most active derivative being P307SQ-8C(>5-log kill). Both P307 and P307SQ-8Cshowed highin vitroactivity againstA. baumanniiin biofilms. Moreover, P307SQ-8Cexhibited MICs comparable to those of levofloxacin and ceftazidime and acted synergistically with polymyxin B. Although the peptides were shown to kill by disrupting the bacterial cytoplasmic membrane, they did not lyse human red blood cells or B cells; however, serum was found to be inhibitory to lytic activity. In a murine model ofA. baumanniiskin infection, P307SQ-8Creduced the bacterial burden by ∼2 logs in 2 h. This study demonstrates the prospect of using peptide derivatives from bacteriophage lysins to treat topical infections and remove biofilms caused by Gram-negative pathogens.

scholarly journals In VitroActivity of Plazomicin against Gram-Negative and Gram-Positive Bacterial Pathogens Isolated from Patients in Canadian Hospitals from 2013 to 2017 as Part of the CANWARD Surveillance Study

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Andrew Walkty ◽  
James A. Karlowsky ◽  
Melanie R. Baxter ◽  
Heather J. Adam ◽  
George G. Zhanel
Keyword(s):  
Antimicrobial Agents ◽  
Bacterial Pathogens ◽  
Multidrug Resistant ◽  
Surveillance Study ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACTThe Clinical and Laboratory Standards Institute (CLSI) broth microdilution method was used to evaluate thein vitroactivities of plazomicin and comparator antimicrobial agents against 7,712 Gram-negative and 4,481 Gram-positive bacterial pathogens obtained from 2013 to 2017 from patients in Canadian hospitals as part of the CANWARD Surveillance Study. Plazomicin demonstrated potentin vitroactivity againstEnterobacteriaceae(MIC90≤ 1 µg/ml for all species tested exceptProteus mirabilisandMorganella morganii), including aminoglycoside-nonsusceptible, extended-spectrum β-lactamase (ESBL)-positive, and multidrug-resistant (MDR) isolates. Plazomicin was equally active against methicillin-susceptible and methicillin-resistant isolates ofStaphylococcus aureus.

scholarly journals Cefepime-Zidebactam (WCK 5222) Activity Tested against Gram-negative Organisms Causing Bloodstream Infections Worldwide

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S374-S375 ◽  
Author(s):  
Helio S Sader ◽  
Mariana Castanheira ◽  
Jennifer M Streit ◽  
Leonard R Duncan ◽  
Robert K Flamm
Keyword(s):  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Asia Pacific ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Research Grant

Abstract Background Zidebactam (ZID), a bicyclo-acyl hydrazide, is a β-lactam enhancer with a dual mechanism of action involving selective and high binding affinity to Gram-negative (GN) PBP2 and β-lactamase inhibition. We evaluated the in vitro activity of cefepime (FEP) combined with ZID against GN organisms causing bloodstream infections (BSI) in hospitals worldwide. Methods A total of 2,094 isolates from 105 medical centers were evaluated. Isolates were collected from Europe (1,050), USA (331), Latin America (LA; 200) and the Asia-Pacific region (AP; 393) in 2015, and China (120) in 2013 by the SENTRY Program. Susceptibility (S) testing was performed by reference broth microdilution method against FEP-ZID (1:1 ratio) and comparators. The collection included 1,809 Enterobacteriaceae (ENT), 170 P. aeruginosa (PSA) and 115 Acinetobacter spp. (ASP). Results FEP-ZID was very active against ENT (MIC50/90 of ≤0.03/0.12 μg/mL) with 99.9 and 100.0% of isolates inhibited at ≤4/4 and ≤8/8 μg/mL, respectively, and retained potent activity against carbapenem-resistant (CRE; n = 44; MIC50/90, 1/4 μg/mL), multidrug-resistant (MDR), and extensively drug-resistant (XDR) isolates (Table). Amikacin (AMK; MIC50/90, 2/4 μg/mL; 97.7% S) was also very active against ENT, and colistin (COL; MIC50/90, 0.12/>8 μg/mL) inhibited only 87.3% of isolates at ≤2 μg/mL. FEP-ZID was highly active against PSA, including isolates resistant to other antipseudomonal β-lactams, MDR (MIC50/90, 4/8 μg/mL) and XDR (MIC50/90, 4/8 μg/mL) isolates. Among the comparators, COL (MIC50/90 of ≤0.5/1 μg/mL; 100.0% S) and AMK (MIC50/90, 4/16 μg/mL; 91.2% S) were the most active agents against PSA. FEP-ZID (MIC50/90, 16/32 μg/mL) was 4-fold more active than FEP against ASP. Conclusion FEP-ZID (WCK 5222) exhibited potent in vitro activity against a large worldwide collection of GN isolates from BSI, including MDR and XDR isolates. These results support further clinical development of WCK 5222 for treating BSI. Disclosures H. S. Sader, Wockhardt Bio Ag: Research Contractor, Research grant; M. Castanheira, Wockhardt Bio Ag: Research Contractor, Research grant; J. M. Streit, Wockhardt Bio Ag: Research Contractor, Research grant; L. R. Duncan, Wockhardt Bio Ag: Research Contractor, Research grant; R. K. Flamm, Wock: Research Contractor, Research support

scholarly journals Antibacterial activities of selected edible plants extracts against multidrug-resistant Gram-negative bacteria

2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Doriane E Djeussi ◽  
Jaurès AK Noumedem ◽  
Jackson A Seukep ◽  
Aimé G Fankam ◽  
Igor K Voukeng ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Edible Plants ◽  
Gram Negative

scholarly journals In Vitro Activity of WCK 5222 (Cefepime-Zidebactam) against Worldwide Collected Gram-Negative Bacilli Not Susceptible to Carbapenems

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
James A. Karlowsky ◽  
Meredith A. Hackel ◽  
Samuel K. Bouchillon ◽  
Daniel F. Sahm
Keyword(s):  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Limiting Factor ◽  
Gram Negative ◽  
Content Type ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method ◽  
Universal Stability

ABSTRACT WCK 5222 (cefepime-zidebactam, 2 g + 1g, every 8 h [q8h]) is in clinical development for the treatment of infections caused by carbapenem-resistant and multidrug-resistant (MDR) Gram-negative bacilli. We determined the in vitro susceptibility of 1,385 clinical isolates of non-carbapenem-susceptible Enterobacterales, MDR Pseudomonas aeruginosa (also non-carbapenem susceptible), Stenotrophomonas maltophilia, and Burkholderia spp. collected worldwide (49 countries) from 2014 to 2016 to cefepime-zidebactam (1:1 ratio), ceftazidime-avibactam, imipenem-relebactam, ceftolozane-tazobactam, and colistin using the CLSI broth microdilution method. Cefepime-zidebactam inhibited 98.5% of non-carbapenem-susceptible Enterobacterales (n = 1,018) at ≤8 μg/ml (provisional cefepime-zidebactam-susceptible MIC breakpoint). Against the subset of metallo-β-lactamase (MBL)-positive Enterobacterales (n = 214), cefepime-zidebactam inhibited 94.9% of isolates at ≤8 μg/ml. Further, it inhibited 99.6% of MDR P. aeruginosa (n = 262) isolates at ≤32 μg/ml (proposed cefepime-zidebactam-susceptible pharmacokinetic/pharmacodynamic MIC breakpoint), including all MBL-positive isolates (n = 94). Moreover, cefepime-zidebactam was active against the majority of isolates of Enterobacterales (≥95%) and P. aeruginosa (99%) that were not susceptible to ceftazidime-avibactam, ceftolozane-tazobactam, imipenem-relebactam, and colistin. Most isolates (99%) of S. maltophilia (n = 101; MIC50, 8 μg/ml; MIC90, 32 μg/ml) and Burkholderia spp. (n = 4; MIC range, 16 to 32 μg/ml) were also inhibited by cefepime-zidebactam at ≤32 μg/ml. The activity of cefepime-zidebactam against carbapenem-resistant Gram-negative bacteria is ascribed to its β-lactam enhancer mechanism of action (i.e., zidebactam binding to penicillin binding protein 2 [PBP2] and its universal stability to both serine β-lactamases and MBLs). The results from this study support the continued development of cefepime-zidebactam as a potential therapy for infections caused by Enterobacterales, P. aeruginosa, and other nonfermentative Gram-negative bacilli where resistance to marketed antimicrobial agents is a limiting factor.

scholarly journals In Vitro antibacterial and antibiotic-potentiation activities of four edible plants against multidrug-resistant gram-negative species

2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Jaurès AK Noumedem ◽  
Marius Mihasan ◽  
Jules R Kuiate ◽  
Marius Stefan ◽  
Dumitru Cojocaru ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Edible Plants ◽  
Gram Negative

scholarly journals Phytochemical Analysis, In vitro Antibacterial Activity and Rate of Kill of Different Fractions of Dacryodes edulis Leaf

2020 ◽  
pp. 23-35
Author(s):  
R. E. Hassan-Olajokun ◽  
A. M. Deji-Agboola ◽  
O. O. Olasunkanmi ◽  
T. A. Banjo ◽  
O. Olaniran ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Phytochemical Screening ◽  
Zones Of Inhibition ◽  
Time Kill ◽  
Dacryodes Edulis

Dacryodes edulis is a fruit tree attaining a height of 18–40 meters mostly grown around the house and rarely in the forest. It has a relatively short trunk and a deep, dense crown and it is native to Africa hence often called African pear. The leaves are a compound with 5-8 pairs of leaflets. Acetone extract/solvent fractions of the leaves of Dacryodes edulis were used. The in vitro antibacterial activities and rate of kill of different fractions were investigated. The phytochemical screening was done by some chemical tests, antibacterial activity by agar well diffusion method and rate of kill was carried out on S. aureus and E. coli organisms. The fractions exhibited antibacterial activities with zones of inhibition ranged between 20 and 30 mm by Aqueous (AQU) fraction while Dichloromethane (DCM) fraction ranged between 22 and 32 mm. The standard antibiotics, streptomycin ranged between 10 and 20 mm and ampicillin between 11 and 27 mm. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of both fractions had range values between 0.78 and 6.25 mg/mL. The phytochemical screening revealed the presence of alkaloids, tannins, saponins, flavonoids, terpenoid and glycoside. Overall, the two fractions had better activities than the standard antibiotics used. The time kill assay showed that the percentage of the cells killed increased with increasing concentrations of the fractions, as well as, contact time intervals. The AQU fraction killed 100% of Escherichia coli and Staphylococcus aureus cells at concentration of 4.68 mg/mL (3 X MIC) within 120 min while DCM fraction killed 100% of Escherichia coli cells within 90 min at a concentration of 4.68 mg/mL and killed 100% of S. aureus cells within 120 min at a concentration of 3.12 mg/mL (2X MIC). In conclusion, D. edulis leaf fraction has a broad spectrum antibacterial activity, with the AQU and DCM fractions being bactericidal as exemplified by the killing rate and MIC index of 2 (ratio of MBC/MIC) for both fractions.

scholarly journals In Vitro Antibacterial Activities of Essential Oils and Extracts of Six Herbals Against Gram-positive and Gram-negative Bacteria

2021 ◽  
Author(s):  
Mansour Amin ◽  
Sousan Akrami ◽  
Farkhondeh Haghparasty ◽  
Atiyeh Hakimi
Keyword(s):  
Essential Oils ◽  
Antimicrobial Properties ◽  
Antibacterial Activities ◽  
Test Method ◽  
Gram Negative Bacteria ◽  
Antibacterial Effects ◽  
Gram Positive ◽  
Minimum Concentration ◽  
Gram Negative

Abstract Background: Today, due to the increasing use of chemical drugs and the spread of microbial resistance to synthetic antibiotics, as well as side effects of drugs, the identification and introduction of plant species with medicinal and antimicrobial properties is very important. In this study, the antimicrobial properties of essential oils and extracts of 6 medicinal plants from Ahvaz region, Iran against 12 Gram-positive and Gram-Negative Bacteria were evaluated. Methods: The EOs and extracts were extracted using water distillation with Clevenger apparatus. The antimicrobial properties and determination of the minimum concentration of growth inhibition of herbals were investigated by the modified E-test method. Results: All analyzed extracts and EOs showed antibacterial effects. The antimicrobial activity of Oliveria decumbens was strongest herbals with the least MIC ranges (0.008-0.1 mg/ml for EO, 0.9-20 mg/ml for extract), while the antibacterial effects of Artemisia vulgaris extract and Glycyrrhiza glabra EO with the highest MIC were weaker than the others. According to the effectiveness of plant extracts on bacteria, Pseudomonas aeruginosa was resistant to all extracts except Oliveria decumbens. In contrast, Bacillus cereus was more sensitive than other strains against analyzed EOs and extracts.Conclusions: It seems that due to the antimicrobial properties of the extracts and essential oils observed in this study, they can be used as an alternative to antimicrobial drugs after more extensive studies.

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