The Effect of Infection Control Nurses on the Occurrence of Pseudomonas aeruginosa Healthcare-Acquired Infection and Multidrug-Resistant Strains in Critically-Ill Children

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae are a serious worldwide public health concern due to the ineffectiveness of empirical antibiotic therapy. Therefore, research and the development of new antibiotic alternatives are urgently needed to control these bacteria. The use of cationic antimicrobial peptides (CAMPs) is a promising candidate alternative therapeutic strategy to antibiotics because they exhibit antibacterial activity against both antibiotic susceptible and MDR strains. In this study, we aimed to investigate the in vitro antibacterial effect of a short synthetic CAMP derived from the ΔM2 analog of Cec D-like (CAMP-CecD) against clinical isolates of K pneumoniae (n = 30) and P aeruginosa (n = 30), as well as its hemolytic activity. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of CAMP-CecD against wild-type and MDR strains were determined by the broth microdilution test. In addition, an in silico molecular dynamic simulation was performed to predict the interaction between CAMP-CecD and membrane models of K pneumoniae and P aeruginosa. The results revealed a bactericidal effect of CAMP-CecD against both wild-type and resistant strains, but MDR P aeruginosa showed higher susceptibility to this peptide with MIC values between 32 and >256 μg/mL. CAMP-CecD showed higher stability in the P aeruginosa membrane model compared with the K pneumoniae model due to the greater number of noncovalent interactions with phospholipid 1-Palmitoyl-2-oleyl-sn-glycero-3-(phospho-rac-(1-glycerol)) (POPG). This may be related to the boosted effectiveness of the peptide against P aeruginosa clinical isolates. Given the antibacterial activity of CAMP-CecD against wild-type and MDR clinical isolates of P aeruginosa and K pneumoniae and its nonhemolytic effects on human erythrocytes, CAMP-CecD may be a promising alternative to conventional antibiotics.

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The role of interventional molecular epidemiology in controlling clonal clusters of multidrug resistant Pseudomonas aeruginosa in critically ill cancer patients

American Journal of Infection Control ◽

10.1016/j.ajic.2008.09.012 ◽

2009 ◽

Vol 37 (6) ◽

pp. 442-446 ◽

Cited By ~ 7

Author(s):

Javier A. Adachi ◽

Cheryl Perego ◽

Linda Graviss ◽

Tanya Dvorak ◽

Ray Hachem ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Molecular Epidemiology ◽

Cancer Patients ◽

Critically Ill ◽

Multidrug Resistant

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Clinically Relevant Plasma Concentrations of Colistin in Combination with Imipenem Enhance Pharmacodynamic Activity against Multidrug-Resistant Pseudomonas aeruginosa at Multiple Inocula

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05028-11 ◽

2011 ◽

Vol 55 (11) ◽

pp. 5134-5142 ◽

Cited By ~ 79

Author(s):

Phillip J. Bergen ◽

Alan Forrest ◽

Jürgen B. Bulitta ◽

Brian T. Tsuji ◽

Hanna E. Sidjabat ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Therapy ◽

Systematic Study ◽

Plasma Concentrations ◽

Multidrug Resistant ◽

Bacterial Killing ◽

Content Type ◽

Resistant Strains ◽

Time Kill

ABSTRACTThe use of combination antibiotic therapy may be beneficial against rapidly emerging resistance inPseudomonas aeruginosa. The aim of this study was to systematically investigatein vitrobacterial killing and resistance emergence with colistin alone and in combination with imipenem against multidrug-resistant (MDR)P. aeruginosa. Time-kill studies were conducted over 48 h using 5 clinical isolates and ATCC 27853 at two inocula (∼106and ∼108CFU/ml); MDR, non-MDR, and colistin-heteroresistant and -resistant strains were included. Nine colistin-imipenem combinations were investigated. Microbiological response was examined by log changes at 6, 24, and 48 h. Colistin combined with imipenem at clinically relevant concentrations increased the levels of killing of MDR and colistin-heteroresistant isolates at both inocula. Substantial improvements in activity with combinations were observed across 48 h with all colistin concentrations at the low inoculum and with colistin at 4× and 16× MIC (or 4 and 32 mg/liter) at the high inoculum. Combinations were additive or synergistic against imipenem-resistant isolates (MICs, 16 and 32 mg/liter) at the 106-CFU inoculum in 9, 11, and 12 of 18 cases (i.e., 9 combinations across 2 isolates) at 6, 24, and 48 h, respectively, and against the same isolates at the 108-CFU inoculum in 11, 7, and 8 cases, respectively. Against a colistin-resistant strain (MIC, 128 mg/liter), combinations were additive or synergistic in 9 and 8 of 9 cases at 24 h at the 106- and 108-CFU inocula, respectively, and in 5 and 7 cases at 48 h. This systematic study provides important information for optimization of colistin-imipenem combinations targeting both colistin-susceptible and colistin-resistant subpopulations.

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Frequency and Antimicrobial Susceptibility Pattern of Pseudomonas Aeruginosa in Human Pus Samples at Holy Family Hospital Rawalpindi

Open Access Journal of Microbiology & Biotechnology ◽

10.23880/oajmb-16000189 ◽

2021 ◽

Vol 6 (1) ◽

pp. 1-8

Author(s):

Kazmi A

Keyword(s):

Pseudomonas Aeruginosa ◽

Nosocomial Infections ◽

Antibiotic Susceptibility ◽

Antimicrobial Agents ◽

Antibiotic Sensitivity ◽

Recovery Process ◽

Multidrug Resistant ◽

Cross Sectional Study ◽

Cross Sectional ◽

Resistant Strains

Background: Nosocomial infections are great threat for hospitalized patients and Pseudomonas aeruginosa has emerged as one of the most potent nosocomial pathogens along with its diverse mechanisms to counter the various antimicrobial agents such as aminoglycosides, fluoroquinolones, monobactems, third generation cephalosporins, carbapenams and broad- spectrum penicillins. P. aeruginosa is one of the well-known pyogenic bacteria and is 3rd leading cause of pyogenic infections with the variable frequency depending on geographical region and clinical setting. P. aeruginosa is intimately associated with pyogenic nosocomial infections. Objectives: Since multidrug resistant strains of P. aeruginosa have posed serious threats and are frequently implicated in nosocomial infections. Methods: Pus swab were sampled under aseptic conditions and cultured on blood and Muller Hinton agar. Gram reaction, pigment production, Oxidase, indole reaction and citrate test were used to confirm isolate. Antibiotic susceptibility was performed b Kirby Bauer technique. Results compiled by us in this cross sectional study, showed 58 cases of P. aeruginosa out of 289 cases. This included 43% males and 57% females. Majority of the patients were of young age, with mean age 38 years. Antibiotic sensitivity revealed resistance to gentamicin was 50%, amikacin was 64%, ciprofloxacin and Aztronem 66%, Cefaparazone 69%, Tzaocin 71% and meropenem and sulzone was 79%. While Colistin and Ceftazidime were the most effective in 85% and 89% of cases respectively. The multidrug resistant strains of P. aeruginosa infections accounted for 32.76% of total P. aeruginosa infections. This study reveals high prevalence of multidrug resistant organisms at the set of our study. Based on this study, we suggest adopting the strategies to minimize the risk of nosocomial infections to slow down the rapidly growing multidrug resistance. These strategies may include, stricter antiseptic measures, fastening the recovery process and reducing the hospital stay and considering other alternates. Besides this, we would like to suggest the precise use of antibiotic susceptibility facility to reduce the nosocomial infection associated complications.

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Weekly Screening for Multidrug-Resistant Organisms Identifies High Number of Colonizations in Patients Undergoing Stem Cell Transplantation

Blood ◽

10.1182/blood-2018-99-118713 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 5703-5703

Author(s):

Silvia Monsalvo ◽

Pascual Balsalobre ◽

Nieves Dorado Herrero ◽

Laura Solán ◽

Ana Fernandez-Cruz ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Stem Cell ◽

Infection Control ◽

Conflicts Of Interest ◽

Urine Culture ◽

Control Strategies ◽

Multidrug Resistant ◽

Febrile Episode ◽

Cell Transplant ◽

Multidrug Resistant Organisms

Abstract Introduction: Multidrug-resistant organisms (MDRO) are a challenge in patients undergoing stem cell transplant (SCT) which often result in an increase in mortality. To our knowledge, current literature defines only screening at the time of work-up for SCT-patients. The aims of the study were to assess the rate of MDRO colonization with weekly screening, rate of infection and the associated mortality in patients undergoing SCT. Patients and methods: Consecutive patients admitted at the SCT unit between January-18 to July-18 were reviewed in our institution. Screening consisted of rectal and perineal swab on admission and weekly until the date of discharge. In case of detection of MDRO , patients were isolated and infection control strategies were applied. Results: 41 patients were analysed, with 47 admissions, 6 patients had 2 admissions. The median duration of hospitalization was 27 days/patient (range 8-100). 168 rectal-and perineal swab were performed with a median of 3 swabs/patient (range 1-7). Patient characteristics are shown in Table 1. 36 patients (87%) spiked fever in a median of 8,5 days after admission (1-38days). 24,4% (n=10) had a positive screening: 2/10 patients at baseline and 8/10 patients (80%) were detected for the first time beyond baseline screen. Rate of MDRO colonization was 3% per week (95%CI 1.4-5.4). MDRO identified were : 4 patients with Extended-spectrum beta-lactamases producing E. Coli (ESBL-EC), Multidrug-resistant (MR) Pseudomonas aeruginosa (n=3), Vancomycin-resistant Enterococci (n=2) and 1 patient with carbapenem-resistant Citrobacter freundii. 6/10 patients developed MDRO infection (60%), all with previous MDRO positive detection: MR-Pseudomonas aeruginosa in urine culture (n=3) 2 treated with ceftolozane/tazobactam, 1 with meropenem+amikacin; ESBL-EC in urine culture (n=2) both treated with meropenem and 1 with Klebsiella pneumoniae carbapenemase in urine culture treated with ceftazidime/avibactam. The infection rate was 4,6% (95% CI 3.9-5.2). In 80% patients (n=8) antibiotic treatment was guided by positive screening, 3 patients were admitted to intensive care unit for sepsis. No mortality was associated to MDRO. In 76%of patients (n=28) screening was negative for MDRO. 24/28 (85%) spiked fever with a median of 10 days after admission (1-38days). None MDRO-infections in negative-screened patients were detected. Conclusions : Weekly screening for MDRO identified a high number of MDRO colonizations allowing to apply early strategies of infection control in high risk patients . Besides, MDRO infection occurred only in patients previously colonized, therefore, 80% of our cohort could benefit from guided treatment by the time of the febrile episode. Early identification of MDRO colonization might have helped to reduce MDRO related mortality. However, these findings should be confirmed with further studies, comparing baseline with weekly MDRO screening strategies. Disclosures No relevant conflicts of interest to declare.

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Detection of Colistin Resistance in Pseudomonas aeruginosa Using the MALDIxin Test on the Routine MALDI Biotyper Sirius Mass Spectrometer

Frontiers in Microbiology ◽

10.3389/fmicb.2021.725383 ◽

2021 ◽

Vol 12 ◽

Author(s):

Katy Jeannot ◽

Katheryn Hagart ◽

Laurent Dortet ◽

Markus Kostrzewa ◽

Alain Filloux ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Lipid A ◽

Response Regulator ◽

Multidrug Resistant ◽

Positive Control ◽

Colistin Resistance ◽

Clinical Strains ◽

Efficient Detection ◽

Maldi Biotyper ◽

Resistant Strains

Colistin is frequently a last resort treatment for Pseudomonas aeruginosa infections caused by multidrug-resistant (MDR) and extensively drug resistant (XDR) strains, and detection of colistin resistance is essential for the management of infected patients. Therefore, we evaluated the recently developed MALDIxin test for the detection of colistin resistance in P. aeruginosa clinical strains using the routine matrix-assisted laser desorption ionization (MALDI) Biotyper Sirius system. The test is based on the detection by mass spectrometry of modified lipid A by the addition of 4-amino-l-arabinose (l-ara4N) molecules on one or two phosphate groups, in strains resistant to colistin. Overproduction of l-Ara4N molecules is mainly due to the constitutive activation of the histidine kinase (PmrB) or the response regulator (PmrA) following an amino-acid substitution in clinical strains. The performance of the test was determined on a panel of 14 colistin-susceptible and 14 colistin-resistant P. aeruginosa clinical strains, the reference strain PAO1 and positive control mutants PmrB (V28G), PmrB (D172), PhoQ (D240–247), and ParR (M59I). In comparison with the broth microdilution (BMD) method, all the susceptible strains (n=14) and 8/14 colistin-resistant strains were detected in less than 1h, directly on whole bacteria. The remaining resistant strains (n=6) were all detected after a short pre-exposure (4h) to colistin before sample preparation. Validation of the method on a larger panel of strains will be the next step before its use in diagnostics laboratories. Our data showed that the MALDIxin test offers rapid and efficient detection of colistin resistant P. aeruginosa and is thus a valuable diagnostics tool to control the spread of these emerging resistant strains.

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725. WCK 5222 (Cefepime/Zidebactam): An In Vitro Assessment of Activity Compared with Current Dual-Antibiotic Options Against Multidrug-Resistant Pseudomonas aeruginosa

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.793 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S325-S325

Author(s):

Elias M Mullane ◽

Lindsay M Avery ◽

David P Nicolau

Keyword(s):

Pseudomonas Aeruginosa ◽

Opportunistic Pathogen ◽

Multidrug Resistant ◽

Gradient Diffusion ◽

Resistant Strains ◽

In Vitro Assessment ◽

Poor Outcomes ◽

Resistance Rates ◽

Selection Of

Abstract Background Pseudomonas aeruginosa (PSA) is an opportunistic pathogen known to cause complications in critically ill patients worldwide. In those at risk of infection with multidrug-resistant strains (MDR-PSA), dual antibiotic therapy is often considered. However, this practice may contribute to rising resistance rates and poor outcomes if empirical selection is suboptimal. WCK 5222 (cefepime/zidebactam), a novel β-lactam/β-lactam enhancer, may offer a solution. Methods Minimum inhibitory concentrations (MICs) were determined for WCK 5222, amikacin (AMK), fosfomycin (FOF), cefepime (FEP), ceftolozane/tazobactam (C/T), and meropenem (MEM) against 18 clinical PSA isolates using gradient diffusion strip (GDS) methods. Activities of FEP, C/T, and MEM in combination with AMK and FOF were assessed using GDS for isolates nonsusceptible to the β-lactam (MICs >8 mg/L, >4/4 mg/L, and >2 mg/L, respectively). Synergy was defined as a fractional inhibitory concentration index ≤ 0.5. Instances of restored β-lactam susceptibility when tested in combination were compared with the proportion of WCK 5222 MICs ≤ 8 mg/L. Results WCK 5222 MICs ranged from 2 to 32 mg/L (MIC50, 8 mg/L). Rates of susceptibility were: AMK (67%), FOF (44%, MIC ≤ 64 mg/L), FEP (6%), C/T (33%), MEM (0%). Combinations with C/T most frequently demonstrated synergy (C/T-FOF, 42%; C/T-AMK, 33%) and restored C/T susceptibility was observed in 42% of assessments with FOF and in 50% with AMK. For FEP combinations, synergy was observed in 29% and 18% of assessments with FOF and AMK, respectively, with restored susceptibility in 6% for both combinations. Synergy occurred in 11% and 6% of assessments of MEM with FOF and AMK, respectively, with zero instances of restored susceptibility. In total, β-lactam susceptibility was restored in 14% (13/94) of combinations compared with 78% (14/18) of WCK 5222 MICs ≤ 8 mg/L. Conclusion In a selection of MDR-PSA isolates that included carbapenem- and C/T-resistant strains, WCK 5222 MICs ≤ 8 mg/L (cefepime susceptible) were observed more frequently than restoration of susceptibility in select β-lactams in combination with FOF or AMK. WCK 5222 monotherapy may offer enhanced coverage of MDR-PSA over empirically selected combination therapies. Disclosures All authors: No reported disclosures.

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