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Prevalence and microbiological and genetic characteristics of multidrug-resistant Pseudomonas aeruginosa over three years in Qatar
- Mazen A. Sid Ahmed, Hamad Abdel Hadi, Sulieman Abu Jarir, Faisal Ahmad Khan, Mohammed A. Arbab, Jemal M. Hamid, Mohammed A. Alyazidi, Muna A. Al-Maslamani, Sini Skariah, Ali A. Sultan, Abdul Latif Al Khal, Bo Söderquist, Emad Bashir Ibrahim, Jana Jass, Hisham Ziglam
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- Journal:
- Antimicrobial Stewardship & Healthcare Epidemiology / Volume 2 / Issue 1 / 2022
- Published online by Cambridge University Press:
- 20 June 2022, e96
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- Article
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Objectives:
Antimicrobial resistance (AMR) is a global priority with significant clinical and economic consequences. Multidrug-resistant (MDR) Pseudomonas aeruginosa is one of the major pathogens associated with significant morbidity and mortality. In healthcare settings, the evaluation of prevalence, microbiological characteristics, as well as mechanisms of resistance is of paramount importance to overcome associated challenges.
Methods:Consecutive clinical specimens of P. aeruginosa were collected prospectively from 5 acute-care and specialized hospitals between October 2014 and September 2017, including microbiological, clinical characteristics and outcomes. Identification and antimicrobial susceptibility test were performed using the BD Phoenix identification and susceptibility testing system, matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF MS), and minimum inhibitory concentration (MIC) test strips. Overall, 78 selected MDR P. aeruginosa isolates were processed for whole-genome sequencing (WGS).
Results:The overall prevalence of MDR P. aeruginosa isolates was 5.9% (525 of 8,892) and showed a decreasing trend; 95% of cases were hospital acquired and 44.8% were from respiratory samples. MDR P. aeruginosa demonstrated >86% resistance to cefepime, ciprofloxacin, meropenem, and piperacillin-tazobactam but 97.5% susceptibility to colistin. WGS revealed 29 different sequence types: 20.5% ST235, 10.3% ST357, 7.7% ST389, and 7.7% ST1284. ST233 was associated with bloodstream infections and increased 30-day mortality. All ST389 isolates were obtained from patients with cystic fibrosis. Encoded exotoxin genes were detected in 96.2% of isolates.
Conclusions:MDR P. aeruginosa isolated from clinical specimens from Qatar has significant resistance to most agents, with a decreasing trend that should be explored further. Genomic analysis revealed the dominance of 5 main clonal clusters associated with mortality and bloodstream infections. Microbiological and genomic monitoring of MDR P. aeruginosa has enhanced our understanding of AMR in Qatar.
Microbial detachment from biofilms
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- By Gillian F. Moore, Environmental Microbiology Research Group, Exeter University, Exeter, UK, Braden C. Dunsmore, Environmental Microbiology Research Group, Exeter University, Exeter, UK, Steven M. Jones, Environmental Microbiology Research Group, Exeter University, Exeter, UK, Christopher W. Smejkal, Environmental Microbiology Research Group, Exeter University, Exeter, UK, Jana Jass, Department of Microbiology, Umeå University, Umeå, Sweden, Paul Stoodley, Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA, Hilary M. Lappin-Scott, Environmental Microbiology Research Group, Exeter University, Exeter, UK
- Edited by David G. Allison, University of Manchester, P. Gilbert, University of Manchester, H. M. Lappin-Scott, University of Exeter, M. Wilson
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- Book:
- Community Structure and Co-operation in Biofilms
- Published online:
- 03 June 2010
- Print publication:
- 23 October 2000, pp 107-128
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Summary
INTRODUCTION
This chapter reviews the broad area of biofilm detachment, the mechanisms of detachment and the methods used to study this important process. Two case studies are included: the first of these focuses on the control of clinical biofilms; the second case study examines detachment in the water industry.
Biofilms are dynamic structures found in a wide variety of both natural and man-made environments. Their formation has been well studied; for example, Characklis (1990) described eight different stages of biofilm accumulation (Table 1 and Fig. 1). There has been much research into the initial attachment of micro-organisms to surfaces, including the effect of electrostatic interactions and electrochemical forces (Bos et al., 1999). The physiological changes that attaching cells undergo have also been examined; for example, the production of surface appendages such as fimbriae (Austin et al., 1998). In contrast to the work undertaken on attachment, detachment has received little attention although many researchers regard it as a crucial stage of biofilm development (Stewart, 1993; Allison et al., 1999).
Bryers (1988) classified the detachment process into four separate groups: abrasion, grazing, erosion and sloughing. Detachment from the biofilm can be directly caused by the collision or rubbing together of surfaces on which the biofilm has developed, leading to abrasive detachment. Larger organisms feeding on the biofilm can indirectly cause detachment through grazing. Erosion and sloughing refer to physical or chemical processes, which indirectly affect the biofilm structure, leading to detachment. Erosion refers to the continual removal of cells or small groups of cells from the biofilm, whereas sloughing is the loss of discrete amounts of biofilm.
2 - Dynamics of Bacterial Biofilm Formation
- Edited by Hilary M. Lappin-Scott, University of Exeter, J. William Costerton, Montana State University
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- Book:
- Microbial Biofilms
- Published online:
- 24 November 2009
- Print publication:
- 06 July 1995, pp 46-63
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Summary
Introduction
Biofilm formation is important in a wide variety of situations: for instance, colonization of pipe surfaces in the food and water industries, metal corrosion due to sulphate reducing bacteria in the shipping and oil industries, and in medicine associated with infections of various tissues (osteomeylitis and endocarditis), dental decay (Addy et al. 1992) and prosthetic implants (Dougherty 1988). Whereas biofilm formation in a chemostat is considered merely an operating nuisance (Bryers 1984), in industrial fermentors such fouling can cause physical damage by the production of metabolites at points on the surface. Biofilms may lead to reduced heat efficiency transfer and reduction in flow rates, and can also act as a resevoir for potential pathogens (Lappin-Scott & Costerton 1989).
Although biofilm formation is frequently associated with being harmful and detrimental, in many instances it can also be beneficial. Biofilms are used in wastewater treatment for the degradation of soluble organic or nitrogenous waste. In nature microbial decomposition of cellulose fibres requires prior attachment of cellulolytic bacteria and Rhizobium cells form biofilms on the roots of leguminous plants where nodules are formed to fix atmospheric nitrogen. Bar-Or (1990) stated the importance of biofilms in stabilizing soil either by acting as cementing agents or flocculating soil particles, thereby improving aeration and water percolation and allowing further microbial growth.
Biofilm formation is difficult to control. A number of authors have reported that biofilm bacteria (sessile) are more resistant to antimicrobial agents than suspended bacteria (planktonic) of the same species (Brown et al. 1988; Anwar et al. 1989). Most commercial biocides and antibiotics were developed and tested for their ability to kill planktonic bacteria (Chopra 1986; Gilbert et al. 1987).