Can P aeruginosa be grown in the laboratory?
P. aeruginosa is a hardy bacterium that can be grown easily in a wide variety of conditions and temperatures. This unit describes the basic techniques to maintain and grow P. aeruginosa in the laboratory. CAUTION: P. aeruginosa is a Biosafety Level 2 (BSL-2) pathogen.
Can P aeruginosa be grown overnight in mops?
When studying effects of particular nutrient sources on P. aeruginosa,the bacteria can be grown overnight in a minimal medium such as MOPS that is supplemented with the selected nutrient sources (see Solutions and Reagents section).
How to prepare P aeruginosa from agar plate?
Because P. aeruginosa grows better with increased aeration, we use 3 ml volumes in 18 mm tubes on a roller drum and 10 to 25 ml in 125 ml flasks Pick a single colony or small amount of bacteria from the agar plate.
What is the best culture medium for electroporation of Pseudomonas aeruginosa?
Liquid cultures of P. aeruginosaare commonly used for many applications. For general experiments, including electroporation (Choi et al., 2006), cultures are grown in LB.
How do you grow Pseudomonas aeruginosa?
We typically grow P. aeruginosa in 18mm glass tubes with 3 ml of media on a roller drum and generally note exponential doubling times for PAO1 of 1 to 1.5 hours in minimal media (such as MOPS Glucose, see Reagents and Solutions) and 25 to 35 minutes in a rich broth such as LB (see Appendix 4A).
How do you get Pseudomonas aeruginosa treatment?
Pseudomonas aeruginosa infections are generally treated with antibiotics. Unfortunately, in people exposed to healthcare settings like hospitals or nursing homes, Pseudomonas aeruginosa infections are becoming more difficult to treat because of increasing antibiotic resistance.
What medication is used to treat Pseudomonas aeruginosa?
Pseudomonas infection can be treated with a combination of an antipseudomonal beta-lactam (eg, penicillin or cephalosporin) and an aminoglycoside. Carbapenems (eg, imipenem, meropenem) with antipseudomonal quinolones may be used in conjunction with an aminoglycoside.
How long does it take to treat Pseudomonas aeruginosa?
Duration of Pseudomonas Aeruginosa Antibiotics are usually administered for between 7 and 14 days, and sometimes longer, depending on the type and severity of the infection.
Does doxycycline treat Pseudomonas?
Pseudomonas can be difficult to treat, as it's resistant to commonly-used antibiotics, like penicillin, doxycycline and erythromycin. You may need to take different antibiotics if you have Pseudomonas. Sometimes antibiotics are unable to clear Pseudomonas from the lungs.
Does ceftriaxone treat Pseudomonas?
Ceftriaxone is also active against many strains of Pseudomonas aeruginosa. NOTE: Methicillin-resistant staphylococci are resistant to cephalosporins, including ceftriaxone.
Does ciprofloxacin treat Pseudomonas?
Ciprofloxacin was well tolerated. This new quinolone seems to be suitable for single drug treatment of Pseudomonas aeruginosa infections in patients with normal host defense mechanisms, while its therapeutic potential in compromised hosts requires further evaluation.
Does levofloxacin treat Pseudomonas?
In conclusion, according to the in vitro activity, levofloxacin could be considered a good option for the treatment of infections sustained by Pseudomonas aeruginosa, and clinical experiments are required to corroborate our in vitro data.
Does metronidazole treat Pseudomonas?
Metronidazole increases the emergence of ciprofloxacin- and amikacin-resistant Pseudomonas aeruginosa by inducing the SOS response | Journal of Antimicrobial Chemotherapy | Oxford Academic.
What does Pseudomonas aeruginosa eat?
Pseudomonas is one of nature's toughest survivors. It can live in many different environments, from soil to water to our own bodies. It does not need much food, and it competes well against other microbes.
Who is at risk for Pseudomonas aeruginosa?
MRSAPseudomonasOther factors that should raise suspicion for infection¶ImmunosuppressionImmunosuppressionRisk factors for MRSA colonization, including: End-stage kidney disease Crowded living conditions (eg, incarceration)Δ Injection drug useΔ Contact sports participationΔ Men who have sex with menΔ8 more rows
Why do I keep getting Pseudomonas?
Pseudomonas Infection Causes and Risk Factors You can get pseudomonas in many different ways. It can grow on fruits and vegetables, so you could get sick from eating contaminated food. It also thrives in moist areas like pools, hot tubs, bathrooms, kitchens, and sinks. The most severe infections occur in hospitals.
What is the quorum sensing system in bacteria?
Among the Gram-negative bacteria, the most well studied quorum-sensing system is the LuxR-LuxI homologous system and the cognate signal molecules : N-acyl-homoserine lactones (AHLs) (3). This quorum-sensing system is widespread among Gram-negative genera and is involved in the regulation of many host-associated phenotypes, including production of virulence factors (5–7) and secondary metabolites (8). Emerging evidence points to the involvement of quorum sensing in biofilm formation and surface motility in the opportunistic pathogens Pseudomonas aeruginosa(9), Burkholderia cepacia(10), and Aeromonas hydrophila(11). These observations suggest that quorum sensing serves to link biofilm formation with virulence factor production. Interestingly, AHL-based cross-talk has been demonstrated between P. aeruginosaand B. cepacia(12) and between S. liquefaciensand P. aeruginosa(13).
Is quorum sensing an antimicrobial?
Quorum sensing–inhibitory compounds might constitute a new generation of antimicrobial agents with applications in many fields, including medicine (human and veterinary), agriculture, and aquaculture, and the associated commercial interests are substantial . Indeed, in recent years a number of biotechnology companies that aim specifically at developing anti–quorum-sensing and anti-biofilm drugs have emerged (QSI Pharma A/S, Lyngby, Denmark; Microbia, Cambridge, Massachusetts, USA; Quorex Pharmaceuticals Inc., Carlsbad, California, USA; and 4SC AG, Martinsried, Germany). Several strategies aiming at the interruption of bacterial quorum-sensing circuits are possible, including (a) inhibition of AHL signal generation, (b) inhibition of AHL signal dissemination, and (c) inhibition of AHL signal reception.
Can antipathogenic drugs be used to control P. aeruginosa?
The ability to control P. aeruginosawith antipathogenic drugs holds great promise that a whole range of opportunistic, pathogenic bacteria can be controlled by similar pharmaceuticals. P. aeruginosais an attractive model organism for such studies, partly because of the recent development of suitable cDNA microarray technology by Affymetrix Inc. (Santa Clara, California, USA). We have used this technique to demonstrate the target specificity of certain first-generation antipathogenic drugs (61). We envision that this approach will be used in many primary research and pharmaceutical laboratories in the future quest for drugs that target specific cellular components or interactions. Given the large number of bacteria that employ quorum-sensing communication systems, chemical attenuation of unwanted bacterial activities rather than bactericidal or bacteriostatic strategies may find application in many different fields, e.g., in medicine, agriculture, and food technology. This new concept is highly attractive because it is unlikely to pose a selective pressure for the development of resistance. The present approach is therefore generic in nature and highly promising for defense against bacterial biofilms encountered in many infectious diseases, on medical implants, and in many industrial facilities and water pipelines.
Does furanone affect quorum sensing?
The natural furanone compounds have little or no effect on the quorum-sensing systems of P. aeruginosa. In collaboration with Staffan Kjelleberg’s research group, we embarked on the process of drug development to find more potent quorum-sensing inhibitors. The natural furanone compounds were modified by chemical synthesis and screened for increased efficacy. Some derivatives of the D. pulchrafuranone compounds were shown to repress quorum sensing in P. aeruginosaand reduce virulence factor expression (60, 61). Because synthetic compounds, which function well against planktonic cells, might be less efficient against biofilm bacteria, the efficacy of these quorum-sensing inhibitor compounds against bacterial biofilms was assayed. By means of AHL monitors built on the P. aeruginosaquorum sensors and the lasB-gfptarget gene, the efficacy of these compounds was measured via GFP expression. The use of the GFP-based single-cell technology in combination with scanning confocal laser microscopy allowed estimation of furanone penetration and half-life and enabled us to identify synthetic compounds that not only inhibited the quorum sensors in the majority of the cells but also led to the formation of flat, undifferentiated biofilms that eventually detached (60). It is notable that the synthetic furanones, in concentrations that significantly lower quorum sensing–controlled gene expression in planktonic cells, were equally active against biofilm bacteria, despite the profoundly different modes of growth. In contrast, classical antibiotics used to treat P. aeruginosainfections, e.g., tobramycin and piperacillin, are required at concentrations 100- to 1,000-fold higher in order to kill biofilm bacteria than in order to kill their planktonic counterparts. In addition, we observed that furanone-treated biofilms were more susceptible to killing by tobramycin than their untreated counterparts (61) (Figure (Figure33).
How many cases of P. aeruginosa were compared with controls?
In a separate population of immunocompromised patients, in a matched case–control study, 31 cases colonized with extensively drug-resistant P. aeruginosa were compared with 93 controls. Four factors were associated with colonization: presence of a central venous catheter, presence of a urinary catheter, CRP>10 mg/L, and ciprofloxacin administration [ 13 ]. Another study, this time in a retrospective international cohort of P. aeruginosa nosocomial pneumonia, tried to determine the risk factors for MDR and attributable mortality [ 14 ]. From 740 patients, 226 were infected with MDR strains. Independent factors predictors of MDR were decreasing age, diabetes mellitus, and ICU admission. MDR was independently associated with in-hospital mortality (44.7 versus 31.7% for non-MDR, p =0.001). A prospective observational study compared imipenem-resistant (IR) P. aeruginosa (PA) with or without MBL-mediated resistance [ 15 ]. The researchers found that the most important predictor of prognosis was imipenem resistance itself and not MBL production – the higher mortality observed in the IR-MBL-PA group was mediated by the underlying diseases, Charlson’s index, and other factors (e.g. virulence). Another retrospective study evaluated the impact of resistance on morbidity, mortality and length of stay with 324 cases and 676 controls [ 16 ]. The authors found that mortality from all causes and 30–day mortality after infection were higher in patients with a resistant pathogen. Pseudomonas was observed in 15.1% of the cases and 19.7% of the controls (second place Gram negative after E. coli ). A systematic review and meta-analysis of the association between resistance and mortality was performed in neutropenic patients [ 17 ]. A total of 30 studies were included; infections related to carbapenems-resistant Pseudomonas spp. were reported in 18 (60%) studies. Globally, mortality ranged from 33 to 71% in patients with carbapenems-resistant Pseudomonas infections. The results showed an increased mortality in carbapenems-resistant compared to carbapenems-susceptible infections (OR 4.89). This increase in mortality has been described in a previous meta-analysis [ 18 ]. Besides mortality, resistance is also associated with increased cost, using the data from 571 admissions with bacteremia, MDR P. aeruginosa bacteremia had the highest mean incremental cost (€ 44,709) [ 19 ].
What are the resistance mechanisms of P. aeruginosa?
Bacteria exhibit multiple resistance mechanisms to antibiotics including decreased permeability, expression of efflux systems, production of antibiotic inactivating enzymes and target modifications. P. aeruginosa exhibits most of these known resistance mechanisms through both intrinsic chromosomally encoded or genetically imported resistance determinants affecting the major classes of antibiotics such as β-lactams, aminoglycosides, quinolones and polymyxins ( Table 1 ). Eight categories of antibiotics are mainly used to treat P. aeruginosa infections including aminoglycosides (gentamicin, tobramycin, amikacin, netilmicin), carbapenems (imipenem, meropenem), cephalosporins (ceftazidime, cefepime), fluoroquinolones (ciprofloxacin, levofloxacin), penicillin with β-lactamase inhibitors (BLI) (ticarcillin and piperacillin in combination with clavulanic acid or tazobactam), monobactams (aztreonam), fosfomycin and polymyxins (colistin, polymyxin B). The strains of P. aeruginosa are categorized as follows: (1) MDR when resistance is observed in ≥1 agent in ≥3 categories; (2) extensively drug-resistant (XDR) when a resistance is observed in ≥ agent in all but ≤ categories; and (3) pandrug-resistant (PDR) when the strain is non-susceptible to all antimicrobial agents [ 2 ]. The emergence of MDR, XDR and PDR strains occurs in a timely fashion by the modification of regulatory mechanisms controlling the expression of resistance determinants, by mutations, alteration of membrane permeability, and horizontal acquisition of antibiotic-inactivating enzymes or enzymes inducing target modifications. Noteworthy, is the multi-resistance of many strains conferred by simultaneous production of these mechanisms [ 3 ].
What is the wild type of P. aeruginosa?
P. aeruginosa wild-type strain encodes an inducible molecular class C AmpC cephalosporinase not inhibited by BLI such as clavulanic acid, tazobactam and sulbactam [ 4 ]. The AmpC cephalosporinase usually exhibits a low level expression which, together with low membrane permeability and multiple efflux systems, confers resistance to aminopenicillins alone or in combination with BLI, first and second generation cephalosporins (C1G, C2G), cephamycins, the two third generation cephalosporins (C3G), cefotaxime and ceftriaxone, as well as the carbapenem, ertapenem [ 5, 6 ]. The P. aeruginosa wild-type strain remains thus susceptible to carboxypenicillin, ureidopenicillin, the C3G ceftazidime, the C4G cefepime, aztreonam and to the carbapenems, imipenem, meropenem and doripenem ( Table 2 ). However, induced or constitutive AmpC overexpression and/or point mutation can provide reduced susceptibility to all classes of β-lactamins except carbapenems [ 5, 6 ]. Unlike the AmpC of Enterobacteriaceae, the AmpC of P. aeruginosa can also affect cefepime [ 5, 6] ( Table 2 ). P. aeruginosa can produce Amber Class A serine β-lactamases of types TEM (Bush functional group 2b), PSE or CARB (carbecillinase, Bush functional group 2c) [ 21, 22] ( Table 2 ). The substrates of these enzymes include mainly carboxypenicillin and ureidopenicillin and they can sometimes resist BLI. These enzymes show variable susceptibility to cefepime, cefpirome and aztreonam, whereas ceftazidime and carbapenem remain always active towards P. aeruginosa strains carrying these β-lactamases types [ 23 ].
What enzymes are used in P. aeruginosa?
aeruginosa including PER, VEB, GES and BEL types [ 23 ]. In addition, ESBL Enterobacteriacae types of enzymes such as TEM, SHV and CTX-M have been identified in P. aeruginosa, likely following horizontal gene transfer [ 24, 25 ]. These Class A types of ESBL enzymes have a low genetic identity but share a similar β-lactam hydrolysis pattern with the development of resistance to carboxypenicillins, ureidopenicillins, C3G and C4G (ceftazidime, cefepime and cefpirome), and aztreonam but not to carbapenems. Moreover, these enzymes are inhibited at various degrees by the BLI clavulanic acid and tazobactam [ 25 ].
How to optimize beta-lactam?
In our opinion, the best way to optimize beta-lactam antibiotic dosing may be the use of prolonged or continuous infusion with the use of a loading dose to ensure early attainment of target concentration exceeding the MIC [ 110 ]. Moreover, although it is not available in most clinical laboratory, we also suggest the use of therapeutic drug monitoring (TDM).
Which drugs have a limited effect on P. aeruginosa?
Other new drugs such as plazomycin, meropenem-vaborbactam and aztreonam-avibactam have a limited effect on P. aeruginosa [ 111 ].
Where are carbapenems resistant?
For example, focusing on carbapenems resistance, 25 to 50% of invasive isolates are resistant in Latvia, Poland, Slovakia, Hungary, Croatia, Serbia, Bulgaria or Greece, and more than 50% of the strains are resistant in Romania.
How does Pseudomonas aeruginosa spread?
Pseudomonas aeruginosa lives in the environment and can be spread to people in healthcare settings when they are exposed to water or soil that is contaminated with these germs. Resistant strains of the germ can also spread in healthcare settings from one person to another through contaminated hands, equipment, or surfaces.
What are the best practices for infection control?
Healthcare providers should pay careful attention to recommended infection control practices, including hand hygiene and environmental cleaning (e.g., cleaning of patient rooms and shared equipment) to reduce the risk of spreading these germs to patients.
Can Pseudomonas aeruginosa be treated with antibiotics?
Pseudomonas aeruginosa infections are generally treated with antibiotics. Unfortunately, in people exposed to healthcare settings like hospitals or nursing homes, Pseudomonas aeruginosa infections are becoming more difficult to treat because of increasing antibiotic resistance.
