scholarly journals Resistance Index of Penicillin-Resistant Bacteria to Various Physicochemical Agents

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
M. Kazemi ◽  
R. Kasra Kermanshahi ◽  
E. Heshmat Dehkordi ◽  
F. Payami ◽  
M. Behjati
Keyword(s):  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Resistance Index ◽  
Resistance Pattern ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Published Data ◽  
Bacterial Strains ◽  
Significant Difference ◽  
The Impact

Widespread use of various antimicrobial agents resulted in the emergence of bacterial resistance. Mechanisms like direct efflux, formation, and sequestration of metals and drugs in complexes and antiporter pumps are some examples. This investigation aims to investigate the resistance pattern of penicillin-resistant bacterial strains to some physicochemical agents. Sensitivity/resistance pattern of common bacterial strains to antimicrobial agents were evaluated by disk diffusion assay. Broth and agar dilution method were used for determination of minimum inhibitory concentration and minimal bactericidal concentration. The impact of UV ray on the bacterial growth under laminar flow hood was measured using photonmeter. Our data demonstrates that the most prevalent metal resistance was against arsenate (95.92%), followed by cadmium (52.04%) and mercury (36.73%). There was significant difference between cetrimide resistances among studied microbial strains especially for P. aeruginosa (). High rate of pathogen resistance to various antibacterial agents in our study supports previously published data. This great rate of bacterial resistance is attributed to the emergence of defense mechanisms developed in pathogens. The higher general bacterial resistance rate among Staphylococcus strains rather than E. coli and P. aeruginosa strains draws attention towards focusing on designing newer therapeutic compounds for Staphylococcus strains.

The Activity of Alkanna Species in vitro Culture and Intact Plant Extracts Against Antibiotic Resistant Bacteria

2019 ◽  
Vol 25 (16) ◽  
pp. 1861-1865 ◽  
Author(s):  
Naira Sahakyan ◽  
Margarit Petrosyan ◽  
Armen Trchounian
Keyword(s):  
Antibiotic Resistance ◽  
Antibacterial Agents ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Plant Origin ◽  
Bacterial Strains ◽  
Biotechnological Production ◽  
Antibiotic Resistant

Overcoming the antibiotic resistance is nowadays a challenge. There is still no clear strategy to combat this problem. Therefore, the urgent need to find new sources of antibacterial agents exists. According to some literature, substances of plant origin are able to overcome bacterial resistance against antibiotics. Alkanna species plants are among the valuable producers of these metabolites. But there is a problem of obtaining the standardized product. So, this review is focused on the discussion of the possibilities of biotechnological production of antimicrobial agents from Alkanna genus species against some microorganisms including antibiotic resistant bacterial strains.

scholarly journals Reviewing Interventions against Enterobacteriaceae in Broiler Processing: Using Old Techniques for Meeting the New Challenges of ESBLE. coli?

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Michaela Projahn ◽  
Ewa Pacholewicz ◽  
Evelyne Becker ◽  
Guido Correia-Carreira ◽  
Niels Bandick ◽  
...  
Keyword(s):  
Broiler Chickens ◽  
Chicken Meat ◽  
Resistant Bacteria ◽  
Published Data ◽  
Cross Contamination ◽  
The European Union ◽  
Bacterial Strains ◽  
Production Chain ◽  
Intervention Measures ◽  
The Impact

Extended-spectrum beta-lactamase- (ESBL-) producing Enterobacteriaceae are frequently detected in poultry and fresh chicken meat. Due to the high prevalence, an impact on human colonization and the spread of antibiotic resistance into the environment is assumed. ESBL-producing Enterobacteriaceae can be transmitted along the broiler production chain but also their persistence is reported because of insufficient cleaning and disinfection. Processing of broiler chickens leads to a reduction of microbiological counts on the carcasses. However, processing steps like scalding, defeathering, and evisceration are critical concerning fecal contamination and, therefore, cross-contamination with bacterial strains. Respective intervention measures along the slaughter processing line aim at reducing the microbiological load on broiler carcasses as well as preventing cross-contamination. Published data on the impact of possible intervention measures against ESBL-producing Enterobacteriaceae are missing and, therefore, we focused on processing measures concerning Enterobacteriaceae, in particularE. colior coliform counts, during processing of broiler chickens to identify possible hints for effective strategies to reduce these resistant bacteria. In total, 73 publications were analyzed and data on the quantitative reductions were extracted. Most investigations concentrated on scalding, postdefeathering washes, and improvements in the chilling process and were already published in and before 2008 (n=42, 58%). Therefore, certain measures may be already installed in slaughterhouse facilities today. The effect on eliminating ESBL-producing Enterobacteriaceae is questionable as there are still positive chicken meat samples found. A huge number of studies dealt with different applications of chlorine substances which are not approved in the European Union and the reduction level did not exceed 3 log10 values. None of the measures was able to totally eradicate Enterobacteriaceae from the broiler carcasses indicating the need to develop intervention measures to prevent contamination with ESBL-producing Enterobacteriaceae and, therefore, the exposure of humans and the further release of antibiotic resistances into the environment.

scholarly journals The Lactococcal dgkB (yecE) and dxsA Genes for Lipid Metabolism Are Involved in the Resistance to Cell Envelope-Acting Antimicrobials

2021 ◽  
Vol 22 (3) ◽  
pp. 1014
Author(s):  
Aleksandra Tymoszewska ◽  
Tamara Aleksandrzak-Piekarczyk
Keyword(s):  
Antimicrobial Peptides ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Cytoplasmic Membrane ◽  
Cross Resistance ◽  
Resistant Bacteria ◽  
Membrane Targeting ◽  
Nucleotide Polymorphisms ◽  
Next Generation ◽  
Lipid Ii

The emergence of antibiotic-resistant bacteria led to an urgent need for next-generation antimicrobial agents with novel mechanisms of action. The use of positively charged antimicrobial peptides that target cytoplasmic membrane is an especially promising strategy since essential functions and the conserved structure of the membrane hinder the development of bacterial resistance. Aureocin A53- and enterocin L50-like bacteriocins are highly cationic, membrane-targeting antimicrobial peptides that have potential as next-generation antibiotics. However, the mechanisms of resistance to these bacteriocins and cross-resistance against antibiotics must be examined before application to ensure their safe use. Here, in the model bacterium Lactococcus lactis, we studied the development of resistance to selected aureocin A53- and enterocin L50-like bacteriocins and its correlation with antibiotics. First, to generate spontaneous resistant mutants, L.lactis was exposed to bacteriocin BHT-B. Sequencing of their genomes revealed single nucleotide polymorphisms (SNPs) in the dgkB (yecE) and dxsA genes encoding diacylglycerol kinase and 1-deoxy-D-xylulose 5-phosphate synthase, respectively. Then, selected mutants underwent susceptibility tests with a wide array of bacteriocins and antibiotics. The highest alterations in the sensitivity of studied mutants were seen in the presence of cytoplasmic membrane targeting bacteriocins (K411, Ent7, EntL50, WelM, SalC, nisin) and antibiotics (daptomycin and gramicidin) as well as lipid II cycle-blocking bacteriocins (nisin and Lcn972) and antibiotics (bacitracin). Interestingly, decreased via the SNPs accumulation sensitivity to membrane-active bacteriocins and antibiotics resulted in the concurrently increased vulnerability to bacitracin, carbenicillin, or chlortetracycline. It is suspected that SNPs may result in alterations to the efficiency of the nascent enzymes rather than a total loss of their function as neither deletion nor overexpression of dxsA restored the phenotype observed in spontaneous mutants.

scholarly journals Antibacterial efficacy of commercially available activated carbon tooth powder: An in vitro study

2020 ◽  
Vol 11 (4) ◽  
pp. 6748-6753
Author(s):  
Padmaja Vangipuram ◽  
Ravishankar P L ◽  
Prem Blaisie Rajula M ◽  
Rajarajeswari S ◽  
Saravanan A V ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Streptococcus Mutans ◽  
Porphyromonas Gingivalis ◽  
Antimicrobial Agents ◽  
Brain Heart Infusion ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Carbon Powder ◽  
Cow Dung

There has been an indiscriminate use of commercial antimicrobials in the previous decades, leading to emergence of multidrug resistant bacteria. This has become a frequent occurrence, so natural antimicrobial agents have grabbed attention of researchers as potential alternatives. Of particular interest is cow dung which has been shown to have antibacterial and antiseptic properties. It is known to be used predominantly in rural areas. This paper aims to evaluate the antibacterial activity of Goshala Activated Carbon toothpowder against three strains of periodontopathogennic and cariogenic bacteria. Standardized strains of Streptococcus mutans, Aggregatibacter actinomycetemcomitans  and Porphyromonas gingivalis were cultured in BHI (Brain Heart Infusion Broth) media and Minimum Inhibitory Concentration (MIC) of Activated Carbon tooth powder was assessed by serial dilution method. Likewise, Amoxicillin, Metronidazole and Chlorhexidine were tested against the same pathogens. Porphyromonas gingivalis, Streptococcus mutans  and Aggregatibacter actinomycetemcomitans were shown to be sensitive at an MIC of 50mg/ml, 25mg/ml and 0.8mg/ml for activated carbon toothpowder respectively. Given some limitations of this study, we can conclude that  activated carbon powder presents a ray of hope in developing a targeted agent for aggressive periodontitis patients.

scholarly journals Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Alginate Production ◽  
Opportunistic Bacteria

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

Role of Antibiotic Lock Therapy for the Treatment of Catheter-Related Bloodstream Infections

2009 ◽  
Vol 32 (9) ◽  
pp. 678-688 ◽  
Author(s):  
Jose L Del Pozo
Keyword(s):  
Antimicrobial Agents ◽  
Therapeutic Option ◽  
Bloodstream Infections ◽  
Resistance Pattern ◽  
Published Data ◽  
Sufficient Power ◽  
Lock Therapy ◽  
Antibiotic Lock ◽  
The Stability ◽  
Systemic Antibiotics

Catheter-related bloodstream infections are often difficult to treat because they are caused by organisms that embed themselves in a bio film layer on the catheter surface, resulting in an increased resistance to antimicrobial agents. Systemic antibiotics are usually administered but, although generally effective in eliminating circulating bacteria, they frequently fail to sterilize the line, leaving the patient at a continuing risk of complications or recurrence. A successful approach to managing these infections requires making an appropriate decision regarding whether the catheter should be removed or retained using antibiotic lock therapy; and choosing the type and duration of antimicrobial therapy based on the type of organism and its resistance pattern. Studies that have evaluated antibiotic lock therapy have varied in the types of antibiotics and concentrations used, the addition of heparin to the solutions, and dwell times in the catheter lumen. Guidelines from the Infectious Diseases Society of America include use of antibiotic lock therapy as a therapeutic option for intraluminal infections when the device is not removed and, although not routine, as prophylaxis for catheter-related infection in select patient populations. However, there are no published guidelines on the concentration of heparin or antibiotics that should be used, and minimal published data on the stability of heparin combinations with antibiotics. It is to be hoped that antibiotic locks will be subject to randomized controlled trials of sufficient power to confirm or refute their use.

Antibiotic adjuvants: a promising approach to combat multidrug resistant bacteria

2021 ◽  
Vol 22 ◽  
Author(s):  
Namita Sharma ◽  
Anil K. Chhillar ◽  
Sweety Dahiya ◽  
Pooja Choudhary ◽  
Aruna Punia ◽  
...  
Keyword(s):  
Drug Targets ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Bacterial Resistance ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibacterial Drugs ◽  
Effective Strategies ◽  
The Impact ◽  
Emergence Of Resistance

The escalating emergence and prevalence of infections caused by multi-drug resistant (MDR) pathogenic bacteria accentuate the crucial need to develop novel and effectual therapeutic strategies to control this threat. Recent past surprisingly indicates a staggering decline in effective strategies against MDR. Different approaches have been employed to minimize the effect of resistance but the question still lingers over the astounding number of drugs already tried and tested to no avail, furthermore, the detection of new drug targets and the action of new antibacterial agents against already existing drug targets also complicate the condition. Antibiotic adjuvants are considered as one such promising approach for overcoming the bacterial resistance. Adjuvants can potentiate the action of generally adopted antibacterial drugs against MDR bacterial pathogens either by minimizing the impact and emergence of resistance or improving the action of antibacterial drugs. This review provides an overview of mechanism of antibiotic resistance, main types of adjuvants and their mode of action, achievements and progression.

scholarly journals Antimicrobial and Antibiofilm Peptides

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 652 ◽  
Author(s):  
Angela Di Somma ◽  
Antonio Moretta ◽  
Carolina Canè ◽  
Arianna Cirillo ◽  
Angela Duilio
Keyword(s):  
Antimicrobial Peptides ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiofilm Activity ◽  
Chronic Infections ◽  
Planktonic Bacteria ◽  
Hostile Environments

The increasing onset of multidrug-resistant bacteria has propelled microbiology research towards antimicrobial peptides as new possible antibiotics from natural sources. Antimicrobial peptides are short peptides endowed with a broad range of activity against both Gram-positive and Gram-negative bacteria and are less prone to trigger resistance. Besides their activity against planktonic bacteria, many antimicrobial peptides also show antibiofilm activity. Biofilms are ubiquitous in nature, having the ability to adhere to virtually any surface, either biotic or abiotic, including medical devices, causing chronic infections that are difficult to eradicate. The biofilm matrix protects bacteria from hostile environments, thus contributing to the bacterial resistance to antimicrobial agents. Biofilms are very difficult to treat, with options restricted to the use of large doses of antibiotics or the removal of the infected device. Antimicrobial peptides could represent good candidates to develop new antibiofilm drugs as they can act at different stages of biofilm formation, on disparate molecular targets and with various mechanisms of action. These include inhibition of biofilm formation and adhesion, downregulation of quorum sensing factors, and disruption of the pre-formed biofilm. This review focuses on the proprieties of antimicrobial and antibiofilm peptides, with a particular emphasis on their mechanism of action, reporting several examples of peptides that over time have been shown to have activity against biofilm.

scholarly journals BIOLOGICAL EVALUATION, QSAR AND MOLECULAR MODELING STUDIES OF 2,4-DICHLOROBENZOIC ACID DERIVATIVES AS ANTIMICROBIAL AGENTS

2019 ◽  
pp. 98-105
Author(s):  
SAMRIDHI THAKRAL ◽  
VIKRAMJEET SINGH
Keyword(s):  
Molecular Modeling ◽  
Antimicrobial Agents ◽  
Structural Characteristics ◽  
Docking Simulation ◽  
Biological Evaluation ◽  
Dilution Method ◽  
Bacterial Strains ◽  
Qsar Studies ◽  
Antimicrobial Potential

Objective: The aim of this study was to evaluate 2,4-dichlorobenzoic acid derivatives as antimicrobial agents through in vitro, QSAR and molecular docking studies. Methods: The compounds were subjected to in vitro antimicrobial screening by test tube dilution method and the structural characteristics governing the antimicrobial potential were studied using QSAR methodology. These compounds were also screened for docking simulation to find out binding confirmation of reported compounds with PDB 1aj0 and 5fsa using AutoDock tools and discovery studio. Results: The antimicrobial evaluation data indicated that compounds 13 and 18 were found to be the most effective against all the bacterial strains and Aspergillus niger while compounds 1 and 14 exhibited more antifungal potential against Candida albicans. QSAR studies confirmed the role of molar refractivity and Balaban index (J) as controlling parameters for antimicrobial potential. Molecular modeling study revealed that compounds interact with the active site of PDB by hydrophobic, hydrogen bonding, and Van der Wall interactions. Conclusion: These test compounds were identified as potent candidates for the control of microbial strains tested, and structural relationship with activity may provide valuable information for further design and synthesis of compounds with antimicrobial potential.

Incidence of Antibiotic Resistant Escherichia Coli in Iraqi Milk Products

1990 ◽  
Vol 53 (10) ◽  
pp. 846-848
Author(s):  
F. M. ABBAR ◽  
H. KH. KADDER
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Resistance Pattern ◽  
Antibiotic Resistant ◽  
Milk Products ◽  
E Coli ◽  
Antimicrobial Sensitivity ◽  
Significant Difference ◽  
Resistance To Penicillin ◽  
Overall Resistance

The antimicrobial sensitivity of 430 Escherichia coli strains isolated from three types of locally processed Iraqi milk products was determined. Four hundred and one (93.2%) isolates were resistant to one or more antimicrobial agents, and only 29 (6.7%) isolates were sensitive to all 12 agents tested. The incidence of resistant E. coli was 95.5%, 90.4% and 84.4% in isolates from cheese, kishfa, and gaymer, respectively. There was no significant difference in resistance among E. coli strains from various milk products. Overall, resistance to penicillin (92.3%), erythromycin (75.8%), cephaloridine (71.9%), ampicillin (57.7%), and tetracycline (37%) was most frequent, whereas isolates were least resistant to kanamycin (7.2%), chloramphenicol (8.1%), nalidixic acid (8.6%), gentamycin (9%), streptomycin (12.5%), trimethoprim (14%), and colistin (18%). The predominant antimicrobial resistance pattern was penicillin, ampicillin, cephaloridine, and erythromycin detected in 77 (18%). The high resistance of E. coli strains isolated from product samples was suggestive of misuse of these drugs in Iraq.

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