Phenotypic and Molecular Characteristics of Pseudomonas Aeruginosa Isolated from Burn Unit

2021 ◽  
Vol 30 (1) ◽  
pp. 19-28
Author(s):  
Yasser M. Ismail ◽  
Sahar M. Fayed ◽  
Fatma M. Elesawy ◽  
Nora Z Abd El-Halim ◽  
Ola S. El-Shimi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Drug Resistant ◽  
Burn Wound ◽  
Burn Wounds ◽  
Related Data ◽  
Genes Encoding

Background: The biggest concern for a burn team is a nosocomial infection in burn patients, which is a significant health issue. Pseudomonas aeruginosa is an extremely troublesome drug-resistant bacterium in the world today. We are now faced with rising P. aeruginosa pan-drug-resistant clones in hospital settings. Objectives: To evaluate the distribution of different virulence factors generated by P. aeruginosa isolated from burn wound infections, together with its antimicrobial susceptibility. Methodology: The isolates reported as P. aeruginosa were further tested for the presence of various phenotypic and genotypic virulence factors including (Biofilm formation, lipase, protease, gelatinase, DNase, bile esculin hydrolysis & hemolysin). Also, genes encoding (nan 1 and Exo A) were investigated by PCR using specific primers. All the isolates were tested for their antimicrobial susceptibility patterns. Results: The study reported that toxins and enzymes were expressed by the tested strains in varying proportions; (92.0%) were producing β-hemolysin, lipase (86%), and protease (86%). The formation of biofilm was observed in 84%. Exo A (70%) was the main virulence gene found in the tested strains. Nan 1 gene was identified in 30% of the samples. 82% of MDRPA isolates were found. There is indeed a relationship between biofilm production and drug resistance, as well as the presence of virulence genes (nan 1 and Exo A) were associated with certain patients and burn wounds characteristics as burn size, burn wound depth, length of hospital stays, and socioeconomic status. Conclusions: Correlation of Pseudomonas aeruginosa virulence profiles with burn wounds and patient-related data can be useful in establishing of an appropriate preventive protocol for hospitalized patients with P. aeruginosa burn serious infections. The targeting of these bacterial virulence arsenals is also a promising approach to developing alternative drugs, which act by attenuating the aggressiveness of the pathogen and reducing its potential to cause vigorous infection.

scholarly journals Antimicrobial Activity of Ceftazidime-Avibactam Tested against Multidrug-Resistant Enterobacteriaceae and Pseudomonas aeruginosa Isolates from U.S. Medical Centers, 2013 to 2016

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Helio S. Sader ◽  
Mariana Castanheira ◽  
Dee Shortridge ◽  
Rodrigo E. Mendes ◽  
Robert K. Flamm
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Large Collection ◽  
Content Type ◽  
Negative Results ◽  
Medical Centers ◽  
Extensively Drug Resistant ◽  
Genes Encoding

ABSTRACT The in vitro activity of ceftazidime-avibactam and many comparator agents was determined against various resistant subsets of organisms selected among 36,380 Enterobacteriaceae and 7,868 Pseudomonas aeruginosa isolates. The isolates were consecutively collected from 94 U.S. hospitals, and all isolates were tested for susceptibility by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories). Enterobacteriaceae isolates resistant to carbapenems (CRE) and/or ceftazidime-avibactam (MIC ≥ 16 μg/ml) were evaluated for the presence of genes encoding extended-spectrum β-lactamases and carbapenemases. Ceftazidime-avibactam inhibited >99.9% of all Enterobacteriaceae at the susceptible breakpoint of ≤8 μg/ml and was active against multidrug-resistant (MDR; n = 2,953; MIC50/90, 0.25/1 μg/ml; 99.2% susceptible), extensively drug-resistant (XDR; n = 448; MIC50/90, 0.5/2 μg/ml; 97.8% susceptible), and CRE (n = 513; MIC50/90, 0.5/2 μg/ml; 97.5% susceptible) isolates. Only 82.2% of MDR Enterobacteriaceae (n = 2,953) and 64.2% of ceftriaxone-nonsusceptible Klebsiella pneumoniae (n = 1,063) isolates were meropenem susceptible. Among Enterobacter cloacae (22.2% ceftazidime nonsusceptible), 99.8% of the isolates, including 99.3% of the ceftazidime-nonsusceptible isolates, were ceftazidime-avibactam susceptible. Only 23 of 36,380 Enterobacteriaceae (0.06%) isolates were ceftazidime-avibactam nonsusceptible, including 9 metallo-β-lactamase producers and 2 KPC-producing strains with porin alteration; the remaining 12 strains showed negative results for all β-lactamases tested. Ceftazidime-avibactam showed potent activity against P. aeruginosa (MIC50/90, 2/4 μg/ml; 97.1% susceptible), including MDR (MIC50/90, 4/16 μg/ml; 86.5% susceptible) isolates, and inhibited 71.8% of isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (n = 628). In summary, ceftazidime-avibactam demonstrated potent activity against a large collection (n = 44,248) of contemporary Gram-negative bacilli isolated from U.S. patients, including organisms resistant to most currently available agents, such as CRE and meropenem-nonsusceptible P. aeruginosa.

scholarly journals Study of quorum-sensing LasR and RhlR genes and their dependent virulence factors in Pseudomonas aeruginosa isolates from infected burn wounds

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Aya Ahmad Elnegery ◽  
Wafaa Kamel Mowafy ◽  
Tarek Ahmed Zahra ◽  
Noha Tharwat Abou El-Khier
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Proteolytic Activity ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Type Species ◽  
Assay Method ◽  
Content Type ◽  
Burn Wounds ◽  
Link Type

Background. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen responsible for burn-wound infection. High incidence, infection severity and increasing resistance characterize P. aeruginosa -induced burn infection. Purpose. To estimate quorum-sensing (QS)-dependent virulence factors of P. aeruginosa isolates from burn wounds and correlate it to the presence of QS genes. Methods. A cross-sectional descriptive study included 50 P . aeruginosa isolates from burn patients in Mansoura University Plastic and Burn Hospital, Egypt. Antibiotic sensitivity tests were done. All isolates were tested for their ability to produce biofilm using a micro-titration assay method. Protease, pyocyanin and rhamnolipid virulence factors were determined using skimmed milk agar, King’s A medium and CTAB agar test, respectively. The identity of QS lasR and rhlR genes was confirmed using PCR. Results. In total, 86 % of isolates had proteolytic activity. Production of pyocyanin pigment was manifested in 66 % of isolates. Altogether, 76 % of isolates were rhamnolipid producers. Biofilm formation was detected in 96 % of isolates. QS lasR and rhlR genes were harboured by nearly all isolates except three isolates were negative for both lasR and rhlR genes and two isolates were positive for lasR gene and negative for rhlR gene. Forty-nine isolates were considered as extremely QS-proficient strains as they produced QS-dependent virulence factors. In contrast, one isolate was a QS deficient strain. Conclusions. QS affects P. aeruginosa virulence-factor production and biofilm in burn wounds. Isolates containing lasR and rhlR seem to be a crucial regulator of virulence factors and biofilm formation in P. aeruginosa whereas the lasR gene positively regulates biofilm formation, proteolytic activity, pyocyanin production and rhamnolipid biosurfactant synthesis. The QS regulatory RhlR gene affects protease and rhamnolipid production positively.

Clinical and molecular epidemiology of community-onset invasive Staphylococcus aureus infection in New Zealand children

2014 ◽  
Vol 142 (8) ◽  
pp. 1713-1721 ◽  
Author(s):  
D. A. WILLIAMSON ◽  
S. R. RITCHIE ◽  
S. A. ROBERTS ◽  
G. W. COOMBS ◽  
M. G. THOMAS ◽  
...  
Keyword(s):  
New Zealand ◽  
Virulence Factors ◽  
Virulence Gene ◽  
Invasive Disease ◽  
Future Research ◽  
Gene Repertoire ◽  
Non Invasive ◽  
Strong Focus ◽  
Genes Encoding ◽  
Community Onset

SUMMARYOur aim was to describe the epidemiology and incidence of community-onset invasive S. aureus disease in children presenting to our hospital, and to compare the clonal complexes and virulence genes of S. aureus strains causing invasive and non-invasive disease. The virulence gene repertoire of invasive disease isolates was characterized using DNA microarray and compared with the virulence gene repertoire of non-invasive S. aureus isolates. Over the study period, 163 children had an invasive S. aureus infection. There was no difference in the distribution of clonal complexes or in the prevalence of genes encoding virulence factors between invasive and non-invasive isolates. Future research should include a strong focus on identifying the host and environmental factors that, along with organism virulence factors, are contributing to the patterns of invasive S. aureus disease observed in New Zealand.

Detection of virulence factors in high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium isolates from a Tunisian hospital

2007 ◽  
Vol 53 (3) ◽  
pp. 372-379 ◽  
Author(s):  
N. Klibi ◽  
K. Ben Slama ◽  
Y. Sáenz ◽  
A. Masmoudi ◽  
S. Zanetti ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Virulence Factors ◽  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Gelatinase Activity ◽  
Genes Encoding ◽  
High Level

Phenotypic and genotypic determination of virulence factors were carried out in 46 high-level gentamicin-resistant (HLGR) clinical Enterococcus faecalis (n = 34) and Enterococcus faecium (n = 12) isolates recovered from different patients in La Rabta Hospital in Tunis, Tunisia, between 2000 and 2003 (all these isolates harboured the aac(6′)–aph(2″) gene). The genes encoding virulence factors (agg, gelE, ace, cylLLS, esp, cpd, and fsrB) were analysed by PCR and sequencing. The production of gelatinase and hemolysin, the adherence to caco-2 and hep-2 cells, and the capacity for biofilm formation were investigated in all 46 HLGR enterococci. The percentages of E. faecalis isolates harbouring virulence genes were as follows: gelE, cpd, and ace (100%); fsrB (62%); agg (56%); cylLLS (41.2%); and esp (26.5%). The only virulence gene detected among the 12 HLGR E. faecium isolates was esp (58%). Gelatinase activity was detected in 22 of the 34 E. faecalis isolates (65%, most of them with the gelE+–fsrB+ genotype); the remaining 12 isolates were gelatinase-negative (with the gelE+–fsrB– genotype and the deletion of a 23.9 kb fragment of the fsr locus). Overall, 64% of the cylLLS-containing E. faecalis isolates showed β-hemolysis. A high proportion of our HLGR E. faecalis isolates, in contrast to E. faecium, showed moderate or strong biofilm formation or adherence to caco-2 and hep-2 cells.

scholarly journals Assessment of the Effectiveness of Silver-Coated Dressing, Chlorhexidine Acetate (0.5%), Citric Acid (3%), and Silver Sulfadiazine (1%) for Topical Antibacterial Effects Against the Multi-Drug Resistant Pseudomonas Aeruginosa Infecting Full-Skin Thickness Burn Wounds on Rats

2013 ◽  
Vol 98 (4) ◽  
pp. 416-423 ◽  
Author(s):  
Hakan Yabanoglu ◽  
Ozgur Basaran ◽  
Cem Aydogan ◽  
Ozlem Kurt Azap ◽  
Feza Karakayali ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Citric Acid ◽  
Topical Therapy ◽  
Silver Sulfadiazine ◽  
Control Group ◽  
Albino Rats ◽  
Skin Thickness ◽  
Drug Resistant ◽  
Antibacterial Effects ◽  
Burn Wound

Abstract The aim of this study was to compare the effects of four different topical antimicrobial dressings on a multi-drug resistant Pseudomonas aeruginosa contaminated full-thickness burn wound rat model. A total of 40 adult male Wistar albino rats were used. The control group (group 1), silver sulfadiazine (1%) group 2, chlorhexidine acetate (0.5%) group 3, citric acid (3%) group 4, and silver-coated dressing group 5 were compared to assess the antibacterial effects of a daily application to a 30% full-skin thickness burn wound seeded 10 minutes earlier with 108 CFU (colony forming unit)/0.5 mL of a multi-drug resistant Pseudomonas aeruginosa strain. Five groups (1 control group and 4 treatment groups) were compared. The administration of third-degree burns to all rats was confirmed based on histopathologic data. The tissue cultures from groups 2 and 5 exhibited significant differences compared to those of the other 3 groups, whereas no significant differences were observed between groups 1, 3, and 4. The effectiveness of the treatments was as follows: 1% silver sulfadiazine > silver-coated dressing > 3% citric acid > 0.5% chlorhexidine acetate > control group. Our results supported the efficacy of topical therapy by silver sulfadiazine and silver-coated dressing on infections caused by multi-drug resistant Pseudomonas spp.

scholarly journals Antibiotic Resistance, Biofilm Formation, and Presence of Genes Encoding Virulence Factors in Strains Isolated from the Pharmaceutical Production Environment

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 130
Author(s):  
Magdalena Ratajczak ◽  
Dorota Kaminska ◽  
Jolanta Dlugaszewska ◽  
Marzena Gajecka
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Production Environment ◽  
Genes Encoding ◽  
Pharmaceutical Production

The spread of bacterial resistance to antibiotics affects various areas of life. The aim of this study was to assess the occurrence of Pseudomonas aeruginosa, and other bacteria mainly from orders Enterobacterales and Staphylococcus in the pharmaceutical production sites, and to characterize isolated strains in the aspects of antibiotic resistance, biofilm formation, and presence of genes encoding virulence factors. Genes encoding selected virulence factors were detected using PCR techniques. Antimicrobial susceptibility testing was applied in accordance with the EUCAST recommendations. A total of 46 P. aeruginosa strains were isolated and 85% strains showed a strong biofilm-forming ability. The qualitative identification of genes taking part in Quorum Sensing system demonstrated that over 89% of strains contained lasR and rhlI genes. An antimicrobial susceptibility testing revealed nine strains resistant to at least one antibiotic, and two isolates were the metallo-β-lactamase producers. Moreover, the majority of P. aeruginosa strains contained genes encoding various virulence factors. Presence of even low level of pathogenic microorganisms or higher level of opportunistic pathogens and their toxic metabolites might result in the production inefficiency. Therefore, the prevention of microbial contamination, effectiveness of sanitary and hygienic applied protocols, and constant microbiological monitoring of the environment are of great importance.

scholarly journals Characterization of clinical extensively drug resistant Pseudomonas aeruginosa from a Chinese teaching hospital

2018 ◽  
Vol 12 (10) ◽  
pp. 835-841
Author(s):  
Mingxiang Zou ◽  
Haichen Wang ◽  
Jian Shui ◽  
Jun Li ◽  
Yongmei Hu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Opportunistic Pathogen ◽  
Polymyxin B ◽  
Microtiter Plate ◽  
Resistance Rate ◽  
Drug Resistant ◽  
Extensively Drug Resistant ◽  
Drug Resistant Strains

Introduction: Pseudomonas aeruginosa, an important opportunistic pathogen, carries multiple virulence factors which contribute to its adaptation and pathogenicity. The goal of this study was to characterize the virulence factors among extensively drug-resistant P. aeruginosa. Methodology: In this study, 63 non-duplicated extensively drug-resistant P. aeruginosa clinical isolates were collected from December 2013 to July 2015. Polymerase chain reaction (PCR) was used to analyze the homogeneity and the type III secretion system. Microtiter plate method was performed to evaluate the ability to form biofilms associated to twitching and swimming motilities. Results: High percentage (96.8%) of isolates was sensitive to polymyxin B, while the resistance rate to other antibiotics (amikacin, aztreonam, ceftazidime, ciprofloxacin, gentamicin, imipenem, levofloxacin, meropenem, piperacillin-tazobactam) ranged from 80.9% to 100%. Enterobacterial repetitive intergenic consensus-PCR detected seven major groups with minimal genetic variation. All the isolates carried exoT gene, 96.8% carried exoY, 69.8% carried exoS, and 31.7% carried exoU gene. Biofilm formation was confirmed in all strains, out of which 41.3% formed strong biofilm. Motilities analysis showed heterogeneous diameters ranging from 6.02 to 26.09 mm for swimming and from 7.60 to 23.34 mm for twitching motilities. Conclusions: Our findings revealed that the clinical P. aeruginosa isolates tested are the major invasive types in nature and multiple virulence factors were commonly carried in the extensively drug-resistant strains.

70 Chlorhexidine Gluconate for Burn Wound Cleansing: Reduction in Multi-drug Resistant Organism Acquisition

2020 ◽  
Vol 41 (Supplement_1) ◽  
pp. S45-S46
Author(s):  
Kelsey L Miller-Willis ◽  
Mini Thomas ◽  
Victor C Joe
Keyword(s):  
Wound Care ◽  
Baseline Period ◽  
Chlorhexidine Gluconate ◽  
Wound Management ◽  
Resistant Organism ◽  
Drug Resistant ◽  
Intact Skin ◽  
Burn Wound ◽  
Burn Wounds ◽  
Burn Unit

Abstract Introduction Daily wound care is an important part of burn wound management to help prevent infection. Literature suggests that daily Chlorhexidine Gluconate (CHG) bathing can reduce the risk of acquiring Multi-Drug Resistant Organisms (MDRO). The purpose of this study was to identify change in overall MDRO acquisition in the Burn Unit with the addition of a 1% CHG solution for wound care to the CHG bathing protocol for burn patients. Methods Prior to March 2018, routine bathing and wound care involved use of CHG-incompatible antibacterial soap and water followed by 2% chlorhexidine gluconate cloths to intact skin. In March 2018, the bathing protocol changed, in consultation with the hospital’s infection prevention program, to involve a 1% CHG solution for burn wounds followed by 2% CHG cloths to intact skin in order to prevent the loss of protective residual CHG due to rinsing with CHG-incompatible soap and water. A solution of 1% CHG was chosen by staff as an acceptable concentration for wound bathing. Adherence was measured through review of daily documentation of bathing in the electronic medical record. Incidences of burn unit-attributable hospital-onset MDRO cultures were reviewed for the following periods: Baseline (Aug 2016-Aug 2017), Phase-In (Sept 2017 – Aug 2018) and Post-Implementation (Sept 2018 – Aug 2019). Results Adherence was >85% throughout the intervention period. No adverse events were noted. Incidences of hospital-onset burn unit MDROs during the following time periods were: 22 cases (Baseline), 15 cases (Phase-In), and 10 cases (Post-Implementation). The most common organisms in the baseline period were Extended-Spectrum b-Lactamase (ESBL) Escherichia coli, MRSA, and Multi Drug Resistant Pseudomonas; and post-implementation, the most common organisms were: MRSA and MDR-Pseudomonas. Conclusions A change to a 1% CHG solution for rinsing burn wounds in the setting of 2% CHG cloths to intact skin was well tolerated and associated with a decline in MDRO acquisition attributable to the burn ICU in the one-year post implementation. Applicability of Research to Practice The use of a 1% CHG solution for burn wounds may help prevent MDRO acquisition in the highly susceptible and unique burn population.

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