scholarly journals Antimicrobial susceptibility pattern of Stenotrophomonas species isolated from Mexico

2020 ◽  
Vol 20 (1) ◽  
pp. 168-181
Author(s):  
Temidayo O Elufisan ◽  
Isabel Cristina Rodriguez-Luna ◽  
Omotayo O Oyedara ◽  
Alejandro Sanchez-Varela ◽  
Virgilio Bocanegra García ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Biochemical Characterization ◽  
Opportunistic Infections ◽  
Clonal Diversity ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Antimicrobial Susceptibility Pattern ◽  
Concentration Technique ◽  
Stenotrophomonas Nitritireducens

Background: Stenotrophomonas species are multi-resistant bacteria with ability to cause opportunistic infections. Objective: We isolated 45 Stenotrophomonas species from soil, sewage and the clinic with the aim of investigating their susceptibility to commonly used antimicrobial agents. Methodology: The identities of isolates were confirmed with 16S rRNA gene sequence and MALDI-TOF analysis. Anti-mi- crobial resistance, biofilm production and clonal diversity were also evaluated. The minimum inhibitory concentration technique as described by Clinical & Laboratory Standards Institute: CLSI Guidelines (CLSI) was employed for the evaluation of isolate susceptibility to antibiotics. Result: Forty-five Stenotrophomonas species which include 36 environmental strains and 9 clinical strains of S. maltophilia were considered in this study. 32 (88.9 %) environmental strains were identified to be S. maltophilia, 2 (5.6 %) were Stenotrophomonas nitritireducens, and 2 (5.6 %) cluster as Stenotrophomonas spp. Stenotrophomonas isolates were resistant to at least six of the antibiotics tested, including Trimethoprim/Sulfamethoxazole (SXT). Conclusion: Environmental isolates from this study were resistant to SXT which is commonly used for the treatment of S. maltophilia infections. This informs the need for good public hygiene as the environment could be a reservoir of multi-resistant bacteria. It also buttresses the importance of surveillance study in the management of bacterial resistance. Keywords: Stenotrophomonas; environmental; biochemical characterization; clonal diversity; anti-microbial susceptibility.  

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 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.

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.

Nanoantibiotics: A Novel Rational Approach to Antibiotic Resistant Infections

2019 ◽  
Vol 20 (9) ◽  
pp. 720-741 ◽  
Author(s):  
Ayse Basak Engin ◽  
Atilla Engin
Keyword(s):  
Drug Resistance ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Multiple Drug Resistance ◽  
Rational Approach ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Stimuli Responsive ◽  
Conventional Antibiotics ◽  
Multiple Drugs

Background: The main drawbacks for using conventional antimicrobial agents are the development of multiple drug resistance due to the use of high concentrations of antibiotics for extended periods. This vicious cycle often generates complications of persistent infections, and intolerable antibiotic toxicity. The problem is that while all new discovered antimicrobials are effective and promising, they remain as only short-term solutions to the overall challenge of drug-resistant bacteria. Objective: Recently, nanoantibiotics (nAbts) have been of tremendous interest in overcoming the drug resistance developed by several pathogenic microorganisms against most of the commonly used antibiotics. Compared with free antibiotic at the same concentration, drug delivered via a nanoparticle carrier has a much more prominent inhibitory effect on bacterial growth, and drug toxicity, along with prolonged drug release. Additionally, multiple drugs or antimicrobials can be packaged within the same smart polymer which can be designed with stimuli-responsive linkers. These stimuli-responsive nAbts open up the possibility of creating multipurpose and targeted antimicrobials. Biofilm formation still remains the leading cause of conventional antibiotic treatment failure. In contrast to conventional antibiotics nAbts easily penetrate into the biofilm, and selectively target biofilm matrix constituents through the introduction of bacteria specific ligands. In this context, various nanoparticles can be stabilized and functionalized with conventional antibiotics. These composites have a largely enhanced bactericidal efficiency compared to the free antibiotic. Conclusion: Nanoparticle-based carriers deliver antibiotics with better biofilm penetration and lower toxicity, thus combating bacterial resistance. However, the successful adaptation of nanoformulations to clinical practice involves a detailed assessment of their safety profiles and potential immunotoxicity.

Antibiotic Cycling and Marketing Into the 21st Century: A Perspective From the Pharmaceutical Industry

2000 ◽  
Vol 21 (S1) ◽  
pp. S32-S35 ◽  
Author(s):  
Bruce S. Lavin
Keyword(s):  
Antimicrobial Resistance ◽  
Pharmaceutical Industry ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Resistance Mechanisms ◽  
Medical Community ◽  
Resistant Bacteria ◽  
Environmental Pressures ◽  
Development Of Resistance ◽  
Antibiotic Cycling

AbstractBefore the development of the first antimicrobial agents, bacteria already had demonstrated an ability to adapt to stress in the environment, resulting in the development of resistance that often makes the prevailing antibiotic treatment ineffective. The response to antimicrobial resistance in the medical community has been to use new or alternative antibiotics not previously used against the resistant bacteria. The pharmaceutical industry has responded to the resistance problem by producing newer antibiotics, either as modifications of currently existing compounds or as combinations of compounds that may inhibit or bypass the bacterial resistance mechanisms. The development of new antibiotics is a lengthy and costly process. To be successful, the pharmaceutical industry must anticipate the changing needs of the medical community, as well as the dynamic process of antimicrobial resistance. The marketing of new antimicrobial agents must be adaptable to the potential environmental pressures that induce bacterial resistance in order to ensure the longevity of the agents.

scholarly journals Strategies for appropriate antibiotic use in intensive care unit

2015 ◽  
Vol 13 (3) ◽  
pp. 448-453 ◽  
Author(s):  
Camila Delfino Ribeiro da Silva ◽  
Moacyr Silva Júnior
Keyword(s):  
Intensive Care ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Empirical Therapy ◽  
Serum Levels ◽  
Antibiotic Use ◽  
Mortality Rates ◽  
Resistant Bacteria ◽  
Duration Of Therapy ◽  
Initial Empirical Therapy

The comsumption of antibiotics is high, mainly in intensive care units. Unfortunately, most are inappropriately used leading to increased multi-resistant bacteria. It is well known that initial empirical therapy with broad-spectrum antibiotics reduce mortality rates. However the prolonged and irrational use of antimicrobials may also increase the risk of toxicity, drug interactions and diarrhea due to Clostridium difficile. Some strategies to rational use of antimicrobial agents include avoiding colonization treatment, de-escalation, monitoring serum levels of the agents, appropriate duration of therapy and use of biological markers. This review discusses the effectiveness of these strategies, the importance of microbiology knowledge, considering there are agents resistant to Staphylococcus aureus andKlebsiella pneumoniae, and reducing antibiotic use and bacterial resistance, with no impact on mortality.

scholarly journals Multidrug-Resistant Acinetobacter baumannii Genetic Characterization and Spread in Lithuania in 2014, 2016, and 2018

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 151
Author(s):  
Tatjana Kirtikliene ◽  
Aistė Mierauskaitė ◽  
Ilona Razmienė ◽  
Nomeda Kuisiene
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Bacterial Infections ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Variable Number Tandem Repeat ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Essential Information ◽  
Acinetobacter Spp

Bacterial resistance to antimicrobial agents plays an important role in the treatment of bacterial infections in healthcare institutions. The spread of multidrug-resistant bacteria can occur during inter- and intra-hospital transmissions among patients and hospital personnel. For this reason, more studies must be conducted to understand how resistance occurs in bacteria and how it moves between hospitals by comparing data from different years and looking out for any patterns that might emerge. Multidrug-resistant (MDR) Acinetobacter spp. was studied at 14 healthcare institutions in Lithuania during 2014, 2016, and 2018 using samples from human bloodstream infections. In total, 194 isolates were collected and identified using MALDI-TOF and VITEK2 analyzers as Acinetobacter baumannii group bacteria. After that, the isolates were analyzed for the presence of different resistance genes (20 genes were analyzed) and characterized by using the Rep-PCR and MLVA (multiple-locus variable-number tandem repeat analysis) genotyping methods. The results of the study showed the relatedness of the different Acinetobacter spp. isolates and a possible circulation of resistance genes or profiles during the different years of the study. This study provides essential information, such as variability and diversity of resistance genes, genetic profiling, and clustering of isolates, to better understand the antimicrobial resistance patterns of Acinetobacter spp. These results can be used to strengthen the control of multidrug-resistant infections in healthcare institutions and to prevent potential outbreaks of this pathogen in the future.

scholarly journals Emerging antibiotic resistant enteric bacterial flora among food animals in Abeokuta, Nigeria

2015 ◽  
Vol 42 (2) ◽  
pp. 255-262
Author(s):  
F. O Olufemi ◽  
P. A. Akinduti ◽  
E. O. Omoshaba ◽  
E. O. Okpara
Keyword(s):  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Bacterial Flora ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Health Concern ◽  
Occurrence Rate ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Food Animals

Bacterial resistance to antibiotic in food animals is an emerging public health concern as a result of increasing multi-resistant bacteria found in Abeokuta. Therefore, occurrence rate and resistant profile of the emerging enteric pathogens were determined in food animals in Abeokuta, Nigeria. Fecal and rectal samples of 82 were randomly collected from food animals such as sheep (30), chicken (37) and pigs (15) in three major farms located in Abeokuta, Nigeria. Enteric bacteria isolates obtained were cultured and identified according to standard protocol. Antibiotic susceptibility testing was performed by disc diffusion method and standard micro-tube dilution assay and resistance profile was carried out. Among the food animals surveyed for resistant enteric pathogens, 46% and 36% were chicken and sheep respectively while 18% were pigs. Complete resistance of 100% was shown by all the enteric bacteria obtained to metronidazole, tetracycline and penicillin while highest rate of Proteus mirabilis (33.5%) and Escherichia coli (20.1%) were multi resistant strains. Uncontrolled use of antimicrobial agents in food animals is shown to be associated with increasing emergence of antimicrobial resistance in food-borne pathogens which could enhance treatment failure and increase morbidity or death among the populace.

scholarly journals Clinical and microbiological characteristics of diabetic foot infection by carbapenem-resistant bacteria in a hospital in southern Brazil

2021 ◽  
pp. 1-10
Author(s):  
Stela Braun ◽  
Marcia Silva
Keyword(s):  
Diabetic Foot ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Hospital Costs ◽  
Resistant Bacteria ◽  
Control Group ◽  
Carbapenem Resistant ◽  
Microbiological Characteristics ◽  
Comorbidity Index ◽  
Almost All

Carbapenem-resistant bacteria are a major cause of diabetic foot (DF) infection. They are resistant to almost all available antimicrobial agents and lead to increased hospital costs. The clinical and microbiological characteristics of DF infection due to these microorganisms and the association of DF with outcomes such as mortality and amputation are not yet well established. This was a retrospective cohort study involving 60 vascular surgery patients who were admitted to Nossa Senhora da Conceição Hospital due to DF infection caused by carbapenem-resistant bacteria and who underwent debridement or amputation, and a control group with 60 randomly selected patients. The analyzed parameters were mortality and amputation rates and patients’ epidemiological and microbiological profiles. A significant association was observed between bacterial resistance and previous amputation, previous hospitalizations, and DF ulcer classification into ischemic and neuroischemic; however, there were no differences in mortality and amputation rates between the groups, even after using the Charlson comorbidity index. Although DF infections by carbapenem-resistant bacteria were not statistically associated with worse outcomes, their study is important given that there are few therapeutic options for treating these specific infections.

scholarly journals Prevalence of Diversified Antibiotic Resistant Bacteria within Sanitation Related Facilities of Human Populated Workplaces in Abbottabad

2020 ◽  
Author(s):  
Jawad Ali ◽  
Malik Owais Ullah Awan ◽  
Gulcin Akca ◽  
Iftikhar Zeb ◽  
Bilal AZ Amin ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Resistance ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Beta Lactam ◽  
Bacterial Strains ◽  
Antibiotic Resistant Bacteria ◽  
Sensitivity Testing ◽  
Antibiotic Resistant

AbstractAntibiotics discovery was a significant breakthrough in the field of therapeutic medicines, but the over (mis)use of such antibiotics (n parallel) caused the increasing number of resistant bacterial species at an ever-higher rate. This study was thus devised to assess the multi-drug resistant bacteria present in sanitation-related facilities in human workplaces. In this regard, samples were collected from different gender, location, and source-based facilities, and subsequent antibiotic sensitivity testing was performed on isolated bacterial strains. Four classes of the most commonly used antibiotics i.e., β-lactam, Aminoglycosides, Macrolides, and Sulphonamides, were evaluated against the isolated bacteria.The antibiotic resistance profile of different (70) bacterial strains showed that the antibiotic resistance-based clusters also followed the grouping based on their isolation sources, mainly the gender. Twenty-three bacterial strains were further selected for their 16s rRNA gene based molecular identification and for phylogenetic analysis to evaluate the taxonomic evolution of antibiotic resistant bacteria. Moreover, the bacterial resistance to Sulphonamides and beta lactam was observed to be the most and to Aminoglycosides and macrolides as the least. Plasmid curing was also performed for MDR bacterial strains, which significantly abolished the resistance potential of bacterial strains for different antibiotics. These curing results suggested that the antibiotic resistance determinants in these purified bacterial strains are present on respective plasmids. Altogether, the data suggested that the human workplaces are the hotspot for the prevalence of MDR bacteria and thus may serve the source of horizontal gene transfer and further transmission to other environments.

Sign in / Sign up

Export Citation Format

Share Document