scholarly journals Laboratory based antimicrobial resistance surveillance for Pseudomonas aeruginosa blood isolates from South Africa

2018 ◽  
Vol 12 (08) ◽  
pp. 616-624
Author(s):  
Ashika Singh-Moodley ◽  
Adriano Duse ◽  
Preneshni Naicker ◽  
Ranmini Kularatne ◽  
Trusha Nana ◽  
...  
Keyword(s):  
South Africa ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Bacterial Infections ◽  
Treatment Guidelines ◽  
Resistance Mechanisms ◽  
Multi Drug Resistance ◽  
Hospital Treatment ◽  
Baseline Information

Introduction: Antimicrobial resistant bacterial infections are widespread globally and increases in antimicrobial resistance presents a major threat to public health. Pseudomonas aeruginosa is an opportunistic healthcare-associated pathogen with high rates of morbidity and mortality and an extensive range of resistance mechanisms. This study describes the antibiotic susceptibility profiles of P. aeruginosa isolates from patients with bacteraemia submitted by sentinel laboratories in South Africa from 2014 to 2015. Methodology: Organism identification and antimicrobial susceptibility testing were done using automated systems. Molecular methods were used to detect common resistance genes and mechanisms. Results: Overall the susceptibility was high for all antibiotics tested with a decrease over the two-year period. There was no change in the MIC50 and MIC90 breakpoints for all antibiotics from 2014 to 2015. The MIC50 was within the susceptible breakpoint range for most antibiotics and the MIC90 was within the susceptible breakpoint range for colistin only. Phenotypically carbapenem non-susceptible isolates harboured the following plasmid-mediated genes: blaVIM (n = 81, 12%) and blaGES (n = 6, 0.9%); blaNDM (n = 4, 0.6%) and blaOXA-48 and variants (n = 3, 0.45%). Porin deletions were observed in one meropenem non-susceptible isolate only, and multi-drug resistance efflux pumps were expressed in the majority of the non-susceptible isolates investigated. BlaVEB-1, blaIMP and blaKPC were not detected. Conclusion: The prevalence of resistance to commonly used antibacterial agents was low for P. aeruginosa isolates and similarly, tested resistance mechanisms were detected in a relatively small proportion of isolates. Findings in this study represent baseline information for understanding antimicrobial susceptibility patterns in P. aeruginosa isolates from blood. Our surveillance report may assist in contributing to hospital treatment guidelines.

Antimicrobial resistance mechanisms, MLST and NG-STAR sequence types of diverse Neisseria gonorrhoeae isolates in KwaZulu-Natal, South Africa

2021 ◽  
Author(s):  
Nireshni Mitchev ◽  
Ravesh Singh ◽  
Mushal Allam ◽  
Stanford Kwenda ◽  
Arshad Ismail ◽  
...  
Keyword(s):  
South Africa ◽  
Antimicrobial Resistance ◽  
Neisseria Gonorrhoeae ◽  
Point Mutations ◽  
Resistance Mechanisms ◽  
Public Healthcare ◽  
Multiple Sequence ◽  
Genotypic Analysis ◽  
Kwazulu Natal ◽  
Sequence Types

Objective: Antimicrobial resistance (AMR) is a major challenge to managing infectious diseases. Africa has the highest incidence of gonorrhoea but there is a lack of comprehensive data from sparse surveillance programs. This study investigated the molecular epidemiology and AMR profiles of Neisseria gonorrhoeae isolates in KwaZulu-Natal province (KZN), South Africa. Methods: Repository isolates, from patients attending public healthcare clinics for STI care, were used for phenotypic and genotypic analysis. Etest® was performed to determine antimicrobial susceptibility. Whole-genome sequencing (WGS) was used to determine epidemiology and to predict susceptibility by detecting resistance-associated genes and mutations. Results: Among the 61 isolates, multiple sequence types were identified. Six isolates were novel as determined by multilocus sequence typing. N.gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) determined 48 sequence types, of which 35 isolates had novel antimicrobial profiles. Two novel penA alleles and eight novel mtrR alleles were identified. Point mutations were detected in gyrA , parC , mtrR , penA , ponA and porB1 . This study revealed a high prevalence of AMR (penicillin 67%, tetracycline 89% and ciprofloxacin 52%). However, spectinomycin, cefixime, ceftriaxone and azithromycin remained 100% effective. Conclusion: This study is one of the first to comprehensively describe the epidemiology and AMR of N. gonorrhoeae in KZN, South Africa and Africa, using WGS. KZN has a wide strain diversity and most of these sequence types have been detected in multiple countries, however more than half of our isolates have novel antimicrobial profiles. Continued surveillance is crucial to monitor the emergence of resistance to cefixime, ceftriaxone and azithromycin.

scholarly journals Antimicrobial Resistance and Biofilm Formation of Pseudomonas aeruginosa

10.3823/846 ◽  
2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Abdelraouf A Elmanama ◽  
Suhaila Al-Sheboul ◽  
Renad I Abu-Dan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Quorum Sensing ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Developmental Stages ◽  
Infection Site ◽  
Major Virulence Factor

Abstract Pseudomonas aeruginosa threatens patient’s care. It is considered as the most complicated health care associated pathogen to be eliminated from infection site. The biofilm forming ability of P. aeruginosa, being a major virulence factor for most pathogenic microorganism, protects it from host immunity and contribute to antibiotic resistance of this organism. It is estimated that about 80% of infectious diseases are due to biofilm mode of growth. Biofilm forming ability of bacteria imparts antimicrobial resistance that leads to many persistent and chronic bacterial infections. The world is becoming increasingly under the threat of entering the “post-antibiotic era”, an era in which the rate of death from bacterial infections is higher than from cancer. This review focus on P. aeruginosa biofilm forming ability; definition, developmental stages, and significance. In addition, the quorum sensing and the antibiotic resistance of this pathogen is discussed. Keywords: Biofilm; bacterial adhesion; Pseudomonas aeruginosa; antimicrobial resistance; quorum sensing.

scholarly journals Antimicrobial Resistance in Oral biofilm: Challenges and Alternatives

2021 ◽  
Vol 12 (1) ◽  
pp. 349-356
Author(s):  
Satish Kumar Sharma ◽  
Shmmon Ahmad
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Target Cells ◽  
Bacterial Cells ◽  
Antimicrobial Drugs ◽  
Oral Infections

Bacterial biofilm has been a major contributor to severe bacterial infections in humans. Oral infections have also been associated with biofilm-forming microbes. Several antimicrobial strategies have been developed to combat bacterial biofilms. However, the complexity of the oral cavity has made it difficult to use common drug treatments. Most effective ways to control normal bacterial infections are rendered ineffective for bacterial biofilms. Due to limited drug concentration availability, drug neutralization or altered phenotype of bacterial cells, different drug have been ineffective to identify the target cells. This leads to the development of the multifaceted phenomenon of antimicrobial resistance (AMR). Biofilm research done so far has been focused on using antimicrobial drugs to target molecular mechanisms of cells. The severity and resistance mechanisms of extracellular matrix (ECM) have been underestimated. The present study describes different antimicrobial strategies with respect to their applications in dental or oral infections. A prospective strategy has been proposed targeting ECM which is expected to provide an insight on biofilm obstinacy and antimicrobial resistance.

scholarly journals Antimicrobial Susceptibility and Clonality of Vaginally Derived Multidrug-Resistant Mobiluncus Isolates in China

2020 ◽  
Vol 64 (8) ◽  
Author(s):  
Xueying Zhang ◽  
Yongying Bai ◽  
Long Zhang ◽  
Mohamed S. Draz ◽  
Zhi Ruan ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Antimicrobial Resistance ◽  
Transposable Element ◽  
Genome Sequencing ◽  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Whole Genome ◽  
Content Type ◽  
High Diversity

ABSTRACT Here, the antimicrobial susceptibility, resistance mechanisms, and clonality of Mobiluncus sp. isolates recovered from gynecological outpatients in China were investigated. Compared to M. mulieris, M. curtisii exhibited higher antimicrobial resistance to metronidazole, clindamycin, and tetracycline. Whole-genome sequencing indicated that the clindamycin resistance gene erm(X) was located on a transposable element, Tn5432, which was composed of two IS1249 sequences. Phylogenetic analysis indicated that Mobiluncus spp. had high diversity, with isolates being grouped into several sporadic clades.

Spanish nationwide survey on Pseudomonas aeruginosa antimicrobial resistance mechanisms and epidemiology

2019 ◽  
Vol 74 (7) ◽  
pp. 1825-1835 ◽  
Author(s):  
Ester del Barrio-Tofiño ◽  
Laura Zamorano ◽  
Sara Cortes-Lara ◽  
Carla López-Causapé ◽  
Irina Sánchez-Diener ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Nationwide Survey ◽  
Resistance Mechanisms

Stress responses as determinants of antimicrobial resistance in Pseudomonas aeruginosa: multidrug efflux and more

2014 ◽  
Vol 60 (12) ◽  
pp. 783-791 ◽  
Author(s):  
Keith Poole
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Environmental Stress ◽  
Stress Responses ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Resistant Organism ◽  
Multidrug Efflux ◽  
Resistance Development ◽  
Endogenous Genes

Pseudomonas aeruginosa is a notoriously antimicrobial-resistant organism that is increasingly refractory to antimicrobial chemotherapy. While the usual array of acquired resistance mechanisms contribute to resistance development in this organism a multitude of endogenous genes also play a role. These include a variety of multidrug efflux loci that contribute to both intrinsic and acquired antimicrobial resistance. Despite their roles in resistance, however, it is clear that these efflux systems function in more than just antimicrobial efflux. Indeed, recent data indicate that they are recruited in response to environmental stress and, therefore, function as components of the organism’s stress responses. In fact, a number of endogenous resistance-promoting genes are linked to environmental stress, functioning as part of known stress responses or recruited in response to a variety of environmental stress stimuli. Stress responses are, thus, important determinants of antimicrobial resistance in P. aeruginosa. As such, they represent possible therapeutic targets in countering antimicrobial resistance in this organism.

scholarly journals Development and Persistence of Antimicrobial Resistance in Pseudomonas aeruginosa: a Longitudinal Observation in Mechanically Ventilated Patients

2007 ◽  
Vol 51 (4) ◽  
pp. 1341-1350 ◽  
Author(s):  
Anita Reinhardt ◽  
Thilo Köhler ◽  
Paul Wood ◽  
Peter Rohner ◽  
Jean-Luc Dumas ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Selective Pressure ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Antimicrobial Treatment ◽  
Aminoglycoside Resistance ◽  
Prolonged Intubation ◽  
Treatment Regimens ◽  
Underlying Mechanisms

ABSTRACT Intubated patients frequently become colonized by Pseudomonas aeruginosa, which is subsequently responsible for ventilator-associated pneumonia. This pathogen readily acquires resistance against available antimicrobials. Depending on the resistance mechanism selected for, resistance might either be lost or persist after removal of the selective pressure. We investigated the rapidity of selection, as well as the persistence, of antimicrobial resistance and determined the underlying mechanisms. We selected 109 prospectively collected P. aeruginosa tracheal isolates from two patients based on their prolonged intubation and colonization periods, during which they had received carbapenem, fluoroquinolone (FQ), or combined β-lactam-aminoglycoside therapies. We determined antimicrobial resistance phenotypes by susceptibility testing and used quantitative real-time PCR to measure the expression of resistance determinants. Within 10 days after the initiation of therapy, all treatment regimens selected resistant isolates. Resistance to β-lactam and FQ was correlated with ampC and mexC gene expression levels, respectively, whereas imipenem resistance was attributable to decreased oprD expression. Combined β-lactam-aminoglycoside resistance was associated with the appearance of small-colony variants. Imipenem and FQ resistance persisted for prolonged times once the selecting antimicrobial treatment had been discontinued. In contrast, resistance to β-lactams disappeared rapidly after removal of the selective pressure, to reappear promptly upon renewed exposure. Our results suggest that resistant P. aeruginosa is selected in less than 10 days independently of the antimicrobial class. Different resistance mechanisms lead to the loss or persistence of resistance after the removal of the selecting agent. Even if resistant isolates are not evident upon culture, they may persist in the lung and can be rapidly reselected.

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