Genotyping, Drug Resistance and Virulence Factors of Candida Species Isolated from Patients Using Long‐Term Inhaled Steroids

2021 ◽  
Author(s):  
Nursel Dikmen ◽  
Nizami Duran ◽  
Emrah Ay ◽  
Funda Cimen ◽  
Erhan Tek
Keyword(s):  
Drug Resistance ◽  
Virulence Factors ◽  
Candida Species ◽  
Inhaled Steroids

Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

2020 ◽  
Vol 26 ◽  
Author(s):  
Madison Tonkin ◽  
Shama Khan ◽  
Mohmmad Younus Wani ◽  
Aijaz Ahmad
Keyword(s):  
Drug Resistance ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Cell Communication ◽  
Natural Compounds ◽  
Quorum Sensing Inhibitors ◽  
Communication Technique ◽  
Multicellular Organisms ◽  
Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

scholarly journals Pseudomonas aeruginosa PA80 is a cystic fibrosis isolate deficient in RhlRI quorum sensing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Syed A. K. Shifat Ahmed ◽  
Michelle Rudden ◽  
Sabrina M. Elias ◽  
Thomas J. Smyth ◽  
Roger Marchant ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Genomic Islands ◽  
Clinical Strain ◽  
Whole Genome ◽  
Synonymous Mutations ◽  
Wide Range

AbstractPseudomonas aeruginosa uses quorum sensing (QS) to modulate the expression of several virulence factors that enable it to establish severe infections. The QS system in P. aeruginosa is complex, intricate and is dominated by two main N-acyl-homoserine lactone circuits, LasRI and RhlRI. These two QS systems work in a hierarchical fashion with LasRI at the top, directly regulating RhlRI. Together these QS circuits regulate several virulence associated genes, metabolites, and enzymes in P. aeruginosa. Paradoxically, LasR mutants are frequently isolated from chronic P. aeruginosa infections, typically among cystic fibrosis (CF) patients. This suggests P. aeruginosa can undergo significant evolutionary pathoadaptation to persist in long term chronic infections. In contrast, mutations in the RhlRI system are less common. Here, we have isolated a clinical strain of P. aeruginosa from a CF patient that has deleted the transcriptional regulator RhlR entirely. Whole genome sequencing shows the rhlR locus is deleted in PA80 alongside a few non-synonymous mutations in virulence factors including protease lasA and rhamnolipid rhlA, rhlB, rhlC. Importantly we did not observe any mutations in the LasRI QS system. PA80 does not appear to have an accumulation of mutations typically associated with several hallmark pathoadaptive genes (i.e., mexT, mucA, algR, rpoN, exsS, ampR). Whole genome comparisons show that P. aeruginosa strain PA80 is closely related to the hypervirulent Liverpool epidemic strain (LES) LESB58. PA80 also contains several genomic islands (GI’s) encoding virulence and/or resistance determinants homologous to LESB58. To further understand the effect of these mutations in PA80 QS regulatory and virulence associated genes, we compared transcriptional expression of genes and phenotypic effects with isogenic mutants in the genetic reference strain PAO1. In PAO1, we show that deletion of rhlR has a much more significant impact on the expression of a wide range of virulence associated factors rather than deletion of lasR. In PA80, no QS regulatory genes were expressed, which we attribute to the inactivation of the RhlRI QS system by deletion of rhlR and mutation of rhlI. This study demonstrates that inactivation of the LasRI system does not impact RhlRI regulated virulence factors. PA80 has bypassed the common pathoadaptive mutations observed in LasR by targeting the RhlRI system. This suggests that RhlRI is a significant target for the long-term persistence of P. aeruginosa in chronic CF patients. This raises important questions in targeting QS systems for therapeutic interventions.

The importance of year-round flea and roundworm prevention in lockdown and beyond

2021 ◽  
Vol 12 (2) ◽  
pp. 54-57
Author(s):  
Ian Wright
Keyword(s):  
Drug Resistance ◽  
Environmental Impact ◽  
Pivotal Role ◽  
Parasite Control ◽  
Treatment Need ◽  
Zoonotic Risk ◽  
Control Protocols

Whether routine preventative deworming regimens for Toxocara spp. in cats and dogs should be used to reduce zoonotic risk, continues to be a subject of much debate. Nurses are on the frontline of giving preventative parasite control advice and it is vital that this is based on the latest evidence to minimise zoonotic risk while ensuring over treatment does not take place. The need for routine year-round flea treatment is also fundamental to parasite control protocols in cats and dogs. The benefits of routine flea treatment need to be considered against the possible environmental impact and drug resistance issues that may be associated with long-term use. Veterinary nurses play a pivotal role in giving accurate parasite control to clients and balancing these factors based on the latest evidence.

scholarly journals Candida albicans exhibits distinct cytoprotective responses to anti-fungal drugs that facilitate the evolution of drug resistance

2020 ◽  
Author(s):  
V Bettauer ◽  
S Massahi ◽  
S Khurdia ◽  
ACBP Costa ◽  
RP Omran ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Drug Exposure ◽  
Fluorescent Imaging ◽  
Late Time ◽  
Transport Mechanisms ◽  
Short Term ◽  
Anti Fungal ◽  
Initial Drug

AbstractWe developed a modified protocol for nanolitre droplet-based single cell sequencing appropriate for fungal settings, and used it to transcriptionally profiled several thousands cells from a prototrophic Candida albicans population and several drug exposed colonies (incl. fluconazole, caspofungin and nystatin). Thousands of cells from each colony were profiled both at early and late time points post-treatment in order to infer survival trajectories from initial drug tolerance to drug resistance. We find that prototrophic C. albicans populations differentially and stochastically express cytoprotective epigenetic programs. For all drugs, there is evidence that tolerant individuals partition into distinct subpopulations, each with a unique survival strategy involving different regulatory programs. These responses are weakly related to changes in morphology (shift from white to opaque forms, or shift from yeast to filamentous forms). In turn, those subpopulations that successfully reach resistance each have a distinct multivariate epigenetic response that coordinates the expression of efflux pumps, chaperones, transport mechanisms, and cell wall maintenance. Live cell fluorescent imaging was used to validate predictions of which molecular responses most often led to survival after drug exposure. Together our findings provide evidence that C. albicans has a robust toolkit of short-term epigenetic cytoprotective responses designed to “buy time” and increase the chance of acquiring long-term resistance.

scholarly journals Multiple drug resistance of Listeria monocytogenes isolated from aborted women by using serological and molecular techniques in Diwaniyah city/ Iraq

2020 ◽  
Author(s):  
Firas Srhan Abd Al-Mayahi ◽  
Saja Mahdey Jaber
Keyword(s):  
Drug Resistance ◽  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Multiple Drug Resistance ◽  
Molecular Techniques ◽  
Multiple Drug ◽  
Immunological Study ◽  
Bacteriological Diagnosis ◽  
Antimicrobial Resistance Genes ◽  
Iraqi Women

Background and Objectives: The study was sought to detect the effect of Listeria monocytogenes on pregnant Iraqi women at Al-Diwaniya hospitals and determination of virulence genes and antimicrobial susceptibility of isolates. Materials and Methods: 360 specimens including blood, urine, vaginal and endocervical were collected from 90 patients with spontaneous abortions. Blood samples were displayed to immunological study and remaining specimens were subjected to bacteriological diagnosis. PCR was used to determine the virulence factors and antimicrobial resistance genes. Results: Fifteen positive samples (16.6%) of patients and thirteen isolates (14.5%) from patients were recognized based on ELISA and PCR assay respectively. The general isolation of L. monocytogenes strains in cases of abortive women was 13/270 (4.8%). L. monocytogenes strains were highly virulent because of presence of virulence factors associated genes, namely actA, hlyA, plcA and prfA in all strains. Multiple drug resistance (MAR) index values of 15.4% of isolates were >0.2. Conclusion: It is necessary for conducting susceptibility testing and to select the suitable antibiotics and avoid the effects of these bacteria in pregnant women.

scholarly journals Comparison of Virulence Factors of Different Candida Species Isolated from the Oral Cavity of Cancer Patients and Normal Individuals

2019 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Mehrnoush Maheronnaghsh ◽  
Mahnaz Fatahinia ◽  
Parvin Dehghan ◽  
Ali Zarei Mahmoudabadi ◽  
Mahnaz Kheirkhah
Keyword(s):  
Oral Cavity ◽  
Cancer Patients ◽  
Virulence Factors ◽  
Candida Species ◽  
Normal Individuals

scholarly journals Stenotrophomonas Maltophilia Peritonitis in a Child: Case Report and Review of Literature

2020 ◽  
Author(s):  
Demet Alaygut ◽  
Caner Alparslan ◽  
Serdar Sarıtaş ◽  
Elif Perihan Öncel ◽  
Önder Yavaşcan ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Peritoneal Dialysis ◽  
Case Report ◽  
Antibiotic Treatment ◽  
Stenotrophomonas Maltophilia ◽  
Multi Drug Resistance ◽  
Review Of Literature ◽  
Dysplastic Kidney ◽  
Success Of Treatment

Stenotrophomonas maltophilia peritonitis has been only occasionally reported in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Because this microorganism has multi-drug resistance, its treatment is hard and long-term. The treatment might not be successful despite all the efforts and the process of peritoneal dialysis, and may terminate with loss of the catheter. In the present paper, S. maltophilia peritonitis developed in a 6-year-old girl patient, who underwent peritoneal dialysis due to bilateral dysplastic kidney, suffered from episodes of peritonitis frequently and required hospitalization, was presented with literature data. Even though the case received multiple antibiotic treatment and underwent endoluminal brushing (EB), the success of treatment could not be achieved. To the best of our knowledge, this patient is the youngest case in the literature.

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