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Alqarni MS, Attar M, Alshammari S, Ambon B, Al Zhrani AA, Alghamdi A, Naebulharam A, Al-Amri A, Altayib H. Common Resistance Patterns in the Burn Unit of a Tertiary Care Center: A Retrospective Observational Study. Cureus 2023; 15:e43896. [PMID: 37746476 PMCID: PMC10511942 DOI: 10.7759/cureus.43896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
Background Nosocomial bacterial infections have been one of the major concerns in the healthcare system. Burn patients, specifically severe cases, are at a high risk of developing bacterial infections compared to others. The most frequent cultures among burn patients are Staphylococcus aureus, Pseudomonas aeruginosa,and Acinetobacter baumannii. There is a scarcity of local data showing the most common infections in burn patients. This research aimed to determine the most common organisms that cause infections in burn unit patients and the antibiotic sensitivity and resistance patterns in King Abdulaziz Medical City (KAMC) in Jeddah. Methodology In this cross-sectional study, data were collected from patients' files into a data collection sheet. All patients in the burn unit with a positive culture were included in the study using a convenient sampling technique from Best-Care, KAMC electronic medical records. Burn patients with negative culture results and patients who were admitted to the plastic surgery ward for reasons other than burns were excluded. For sample size calculation, convenience sampling of 109 patient medical charts, over the study period from June 2016 to November 2021, was selected for data extraction, analysis, and reporting. Results Pseudomonas aeruginosa was the leading cause of infection in burn patients comprising 33.9% of the cases. Enterobacter cloacae was the second most frequent cause of infection among burn patients (27.5%). Klebsiella pneumoniae was the third most frequent cause of infection (26.6%) while Acinetobacter baumannii was the fourth most frequent cause of infection in burn patients (22.9%). Conclusions Understanding the local epidemiology of bacterial infections will be crucial for the development of treatment guidelines designed to standardize initial antibiotic use, reduce hospital-acquired infections, and reduce drug resistance. More attention should be paid to gram-negative bacteria, specifically Pseudomonas aeruginosa and Enterobacter Cloacae.
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Affiliation(s)
- Mohammed S Alqarni
- Internal Medicine, King Abdullah International Medical Research Center, Jeddah, SAU
- Internal Medicine, National Guard Hospital, King Abdulaziz Medical City, Jeddah, SAU
| | - Meshari Attar
- Research Office, King Abdullah International Medical Research Center, Jeddah, SAU
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, SAU
| | - Salem Alshammari
- Internal Medicine, National Guard Hospital, King Abdulaziz Medical City, Jeddah, SAU
- Internal Medicine, King Abdullah International Medical Research Center, Jeddah, SAU
| | - Badr Ambon
- Emergency, Ministry of Health, Mikhwah General Hospital, Al-Baha, SAU
| | | | - Abdullah Alghamdi
- Radiology, National Guard Hospital, King Abdulaziz Medical City, Jeddah, SAU
- Radiology, King Abdullah International Medical Research Center, Jeddah, SAU
| | - Ahmad Naebulharam
- Internal Medicine, National Guard Hospital, King Abdulaziz Medical City, Jeddah, SAU
- Internal Medicine, King Abdullah International Medical Research Center, Jeddah, SAU
| | - Abdulfattah Al-Amri
- Pathology and Laboratory Medicine, King Abdullah International Medical Research Center, Jeddah, SAU
- Pathology and Laboratory Medicine, National Guard Hospital, King Abdulaziz Medical City, Jeddah, SAU
| | - Hadeel Altayib
- Internal Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, SAU
- Internal Medicine, King Abdullah International Medical Research Center, Jeddah, SAU
- Internal Medicine, National Guard Hospital, King Abdulaziz Medical City, Jeddah, SAU
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2
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Ruegsegger L, Xiao J, Naziripour A, Kanumuambidi T, Brown D, Williams F, Marshall SH, Rudin SD, Yen K, Chu T, Chen L, Sozzi E, Bartelt L, Kreiswirth B, Bonomo RA, van Duin D. Multidrug-Resistant Gram-Negative Bacteria in Burn Patients. Antimicrob Agents Chemother 2022; 66:e0068822. [PMID: 36066237 PMCID: PMC9487463 DOI: 10.1128/aac.00688-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/15/2022] [Indexed: 11/20/2022] Open
Abstract
Patients with burn injuries are at high risk for infectious complications, and infections are the most common cause of death after the first 72 h of hospitalization. Hospital-acquired infections caused by multidrug resistant (MDR) Gram-negative bacteria (GNB) in this population are concerning. Here, we evaluated carriage with MDR GNB in patients in a large tertiary-care burn intensive care unit. Twenty-nine patients in the burn unit were screened for intestinal carriage. Samples were cultured on selective media. Median time from admission to the burn unit to first sample collection was 9 days (IQR 5 - 17 days). In 21 (72%) patients, MDR GNB were recovered; the most common bacterial species isolated was Pseudomonas aeruginosa, which was found in 11/29 (38%) of patients. Two of these patients later developed bloodstream infections with P. aeruginosa. Transmission of KPC-31-producing ST22 Citrobacter freundii was detected. Samples from two patients grew genetically similar C. freundii isolates that were resistant to ceftazidime-avibactam. On analysis of whole-genome sequencing, blaKPC-31 was part of a Tn4401b transposon that was present on two different plasmids in each C. freundii isolate. Plasmid curing experiments showed that removal of both copies of blaKPC-31 was required to restore susceptibility to ceftazidime-avibactam. In summary, MDR GNB colonization is common in burn patients and patient-to-patient transmission of highly resistant GNB occurs. These results emphasize the ongoing need for infection prevention and antimicrobial stewardship efforts in this highly vulnerable population.
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Affiliation(s)
- Laura Ruegsegger
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jamie Xiao
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Arash Naziripour
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Trey Kanumuambidi
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Dylan Brown
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Felicia Williams
- Department of Surgery, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Steven H. Marshall
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
| | - Susan D. Rudin
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Kelly Yen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Tingyu Chu
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Liang Chen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Emanuele Sozzi
- Department of Environmental Science and Engineering, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Luther Bartelt
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Barry Kreiswirth
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Robert A. Bonomo
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Departments of Pharmacology, Molecular Biology and Microbiology, Biochemistry, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, Ohio, USA
| | - David van Duin
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
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3
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Bustos D, Hernández-Rodríguez EW, Poblete H, Alzate-Morales J, Challier C, Boetsch C, Vergara-Jaque A, Beassoni P. Structural Insights into the Inhibition Site in the Phosphorylcholine Phosphatase Enzyme of Pseudomonas aeruginosa. J Chem Inf Model 2022; 62:3067-3078. [PMID: 35670773 DOI: 10.1021/acs.jcim.2c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pseudomonas aeruginosa is a highly pathogenic Gram-negative microorganism associated with high mortality levels in burned or immunosuppressed patients or individuals affected by cystic fibrosis. Studies support a colonization mechanism whereby P. aeruginosa can breakdown the host cell membrane phospholipids through the sequential action of two enzymes: (I) hemolytic phospholipase C acting upon phosphatidylcholine or sphingomyelin to produce phosphorylcholine (Pcho) and (II) phosphorylcholine phosphatase (PchP) that hydrolyzes Pcho to generate choline and inorganic phosphate. This coordinated action provides the bacteria with carbon, nitrogen, and inorganic phosphate to support growth. Furthermore, PchP exhibits a distinctive inhibition mechanism by high substrate concentration. Here, we combine kinetic assays and computational approaches such as molecular docking, molecular dynamics, and free-energy calculations to describe the inhibitory site of PchP, which shares specific residues with the enzyme's active site. Our study provides insights into a coupled inhibition mechanism by the substrate, allowing us to postulate that the integrity of the inhibition site is needed to the correct functioning of the active site. Our results allow us to gain a better understanding of PchP function and provide the basis for a rational drug design that might contribute to the treatment of infections caused by this important opportunistic pathogen.
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Affiliation(s)
- Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile.,Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Erix W Hernández-Rodríguez
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile.,Escuela de Química y Farmacia, Facultad de Medicina, Universidad Católica del Maule, Talca 3460000, Chile
| | - Horacio Poblete
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 1 Poniente 1141, Talca 3465548, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3465548, Chile
| | - Jans Alzate-Morales
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 1 Poniente 1141, Talca 3465548, Chile
| | - Cecilia Challier
- Instituto para el Desarrollo Agroindustrial y de la Salud (IDAS), CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina
| | - Cristhian Boetsch
- Instituto de Biotecnología Ambiental y Salud (INBIAS), CONICET, Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina
| | - Ariela Vergara-Jaque
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 1 Poniente 1141, Talca 3465548, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3465548, Chile
| | - Paola Beassoni
- Instituto de Biotecnología Ambiental y Salud (INBIAS), CONICET, Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina
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4
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Chen H, Yang L, Cheng L, Hu XH, Shen YM. Distribution and drug resistance of pathogens in burn patients in China from 2006 to 2019. World J Clin Cases 2021; 9:2228-2237. [PMID: 33869598 PMCID: PMC8026851 DOI: 10.12998/wjcc.v9.i10.2228] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/31/2021] [Accepted: 02/25/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND In this study, recent trends in the distribution and drug resistance of pathogenic bacteria isolated from patients treated at a burn ward between 2006 and 2019 were investigated.
AIM To develop more effective clinical strategies and techniques for the prevention and treatment of bacterial infections in burn patients.
METHODS Clinical samples with positive bacteria were collected from patients at the burn ward in Beijing Jishuitan Hospital in China between January 2006 and December 2019. The samples were retrospectively analyzed, the distribution of pathogenic bacteria was determined, and the trends and changes in bacterial drug resistance during different period were assessed. Drug resistance in several main pathogenic bacteria from 2006 to 2011 and from 2012 to 2019 was comparatively summarized and analyzed.
RESULTS Samples from 17119 patients were collected and analyzed from 2006 to 2019. Surprisingly, a total of 7960 strains of different pathogenic bacteria were isolated at this hospital. Among these bacteria, 87.98% (7003/7960) of the strains were isolated from burn wounds, and only 1.34% (107/7960) were isolated from the blood of patients. In addition, 49.70% (3956/7960) were identified as Gram-positive bacteria, 48.13% (3831/7960) were Gram-negative bacteria, and the remaining 2.17% (173/7960) were classified as fungi or other pathogens. Importantly, Staphylococcus aureus (21.68%), Pseudomonas aeruginosa (14.23%), and Staphylococcus epidermidis (9.61%) were the top three pathogens most frequently isolated from patients.
CONCLUSION In patients treated at the burn ward in this hospital from 2006 to 2019, Staphylococcus aureus and Pseudomonas aeruginosa were the predominant clinical pathogens responsible for bacterial infections. The circumstantial detection and detailed monitoring of the intensity and growth of different pathogenic bacteria in clinical patients as well as tests of drug sensitivity during burn recovery are particularly important to provide guidelines for the application of antibiotics and other related drugs. Careful collection and correct, standard culture of bacterial specimens are also crucial to improve the efficiency of bacterial infection detection. Effective monitoring and timely clinical treatment in patients may help reduce the possibility and rate of infection as well as alleviate the effects of drug resistance among patients in burn centers.
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Affiliation(s)
- Hui Chen
- Department of Burns and Plastic Surgery, Beijing Jishuitan Hospital, Beijing 100035, China
| | - Lin Yang
- Department of Healthcare Associated Infection Control, Beijing Jishuitan Hospital, Beijing 100035, China
| | - Lin Cheng
- Department of Burns and Plastic Surgery, Beijing Jishuitan Hospital, Beijing 100035, China
| | - Xiao-Hua Hu
- Department of Burns and Plastic Surgery, Beijing Jishuitan Hospital, Beijing 100035, China
| | - Yu-Ming Shen
- Department of Burns and Plastic Surgery, Beijing Jishuitan Hospital, Beijing 100035, China
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5
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Ladhani HA, Yowler CJ, Claridge JA. Burn Wound Colonization, Infection, and Sepsis. Surg Infect (Larchmt) 2020; 22:44-48. [PMID: 33085576 DOI: 10.1089/sur.2020.346] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Background: Infection is a major cause of morbidity and mortality among burn patients, and it is important to understand the progression of wound colonization to wound infection to systemic sepsis. Methods: After a review of the literature we describe the clinical characteristics of burn wound colonization, infection, and sepsis, and conclude with best practices to decrease these complications. Results: Burn wounds are initially sterile after the thermal insult but become colonized by gram-positive organisms and subsequently by gram-negative organisms. Some populations are especially susceptible to initial or subsequent colonization by drug-resistant organisms. An increase in fungal colonization has been observed because of the widespread use of topical antibiotic agents. Male gender, older age, lower extremity burn, scald burn, full-thickness burn, delay in treatment, and pre-existing diabetes place patients at increased risk of infection. These infections range from cellulitis that requires systemic antibiotic agents, to invasive burn wound infection that requires prompt treatment with antibiotic agents and excision. Fungal wound infections pose a special challenge and cause substantial morbidity. Infection that leads to systemic sepsis is difficult to define in burn patients because of the body's compensatory hypermetabolic response to the burn injury. Potential sources of sepsis include wound infections and common nosocomial infections. The American Burn Association Sepsis criteria, defined in 2007, has demonstrated poor specificity for identifying sepsis and septic shock. The best approach to decrease wound infections is prevention. Practices that have been beneficial include isolation rooms, handwashing, appropriate wound care, early excision and grafting, antibiotic stewardship, and nutritional support. Conclusions: A burn patient remains at a substantial risk of wound infection despite advances in care. A burn care provider must understand the natural progression of colonization to infection to sepsis, and the multidisciplinary approach to wound care to limit the morbidity and mortality from these infectious.
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Affiliation(s)
- Husayn A Ladhani
- Department of Surgery, Division of Trauma, Critical Care, Burns, and Acute Care Surgery, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, Ohio, USA
| | - Charles J Yowler
- Department of Surgery, Division of Trauma, Critical Care, Burns, and Acute Care Surgery, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, Ohio, USA
| | - Jeffrey A Claridge
- Department of Surgery, Division of Trauma, Critical Care, Burns, and Acute Care Surgery, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, Ohio, USA
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6
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Gholami M, Chirani AS, Razavi S, Falak R, Irajian G. Immunogenicity of a fusion protein containing PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice. Lett Appl Microbiol 2017; 65:439-445. [PMID: 28857243 DOI: 10.1111/lam.12796] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/10/2017] [Accepted: 08/23/2017] [Indexed: 11/30/2022]
Abstract
Interference with bacterial adhesion is a new means to prevent or treat bacterial infections. In this experimental study we evaluated the immunogenic properties of a chimeric protein composed of PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice as an anti-adhesion based vaccine. First of all, a chimeric bivalent protein composed of PilQ and PilA was constructed and following subcutaneous immunization with merely the purified protein or in its admixed form with alum, the immunogenicity of the chimeric antigen was assessed in BALB/c mice. Then, the characteristics of the developed antibodies were studied by ELISA. Furthermore, the immunoreactivity of the purified recombinant protein was confirmed by immunoblotting. Alum as a common adjuvant boosted immunogenicity of the construct, resulting significantly greater anti-pili IgG titre. Mice antibody response consisted of IgG1, IgG2a, IgG2b and IgG3 subtypes with predominance of IgG1 subclass. The developed antibodies were capable to inhibit motility of PAO1 strain. In conclusion, our primary results revealed that the designed recombinant protein is a protective construct and may be used as a potential candidate for prophylactic purposes against P. aeruginosa infection. SIGNIFICANCE AND IMPACT OF THE STUDY In this study we examined the potential of integrated PilQ/PilA (QA) antigen as a vaccine candidate against Pseudomonas aeruginosa. Nowadays, anti-adhesion based vaccines are considered as new means to prevent or treat bacterial infections. Our study revealed that chimeric protein PilQ and disulphide turn region of PilA triggers production of specific antibodies. This humoral immune responses augmented when QA was administered in combination with an adjuvant. The results demonstrated efficacy of the designed recombinant chimeric antigen as an effective candidate in prevention of P. aeruginosa infection.
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Affiliation(s)
- M Gholami
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - A S Chirani
- Department of Medical Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - S Razavi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.,Microbial Biotechnology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - R Falak
- Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - G Irajian
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.,Microbial Biotechnology Research Center, Iran University of Medical Sciences, Tehran, Iran
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7
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Maroui I, Barguigua A, Aboulkacem A, Elhafa H, Ouarrak K, Sbiti M, Louzi L, Timinouni M, Belhaj A. Clonal Analysis of Clinical and Environmental Pseudomonas aeruginosa Isolates from Meknes Region, Morocco. Pol J Microbiol 2017; 66:397-400. [PMID: 29319518 DOI: 10.5604/01.3001.0010.4882] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
From 123 clinical and environmental Pseudomonas aeruginosa isolates, 24 strains were selected for their similar antibioresistance, virulence and biofilm formation profiles, to examine their diversity and occurrence of clones within two hospitals and different natural sites in Meknes (Morocco). Pulsed-field gel electrophoresis, using DraI enzyme, didn't reveal a close relationship between clinical and environmental isolates nor between strains of the two hospitals. 19 genotypes were obtained, including two virulent environmental clones and three clinical clones virulent and resistant to antibiotics. Intra-hospital transmission of high-risk clones detected, in and between wards, constitutes a great public health concern.
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Affiliation(s)
- Itto Maroui
- Ecology and Biodiversity of Wetlands Team, Department of Biology, Faculty of Sciences, Moulay Ismail University, Meknes, Morocco
| | - Abouddihaj Barguigua
- Molecular Bacteriology Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Asmae Aboulkacem
- Ecology and Biodiversity of Wetlands Team, Department of Biology, Faculty of Sciences, Moulay Ismail University, Meknes, Morocco
| | - Hanane Elhafa
- Ecology and Biodiversity of Wetlands Team, Department of Biology, Faculty of Sciences, Moulay Ismail University, Meknes, Morocco
| | - Khadija Ouarrak
- Medical Biology Laboratory of Regional Hospital Mohammed V Meknes, Morocco
| | - Mohammed Sbiti
- Medical Biology Laboratory of Regional Military Hospital Moulay Ismail Meknes, Morocco
| | - Lhoussain Louzi
- Medical Biology Laboratory of Regional Military Hospital Moulay Ismail Meknes, Morocco
| | - Mohammed Timinouni
- Molecular Bacteriology Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Abdelhaq Belhaj
- Ecology and Biodiversity of Wetlands Team, Department of Biology, Faculty of Sciences, Moulay Ismail University, Meknes, Morocco
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8
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Lee C, Walker SAN, Walker SE, Seto W, Simor A, Jeschke M. A prospective study evaluating tobramycin pharmacokinetics and optimal once daily dosing in burn patients. Burns 2017. [PMID: 28647460 DOI: 10.1016/j.burns.2017.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Once-daily aminoglycoside dosing (ODA) is used in most patient populations to optimize antibacterial activity and reduce toxicity. Unfortunately, burn patients are excluded from ODA due to concerns over altered pharmacokinetics resulting in a shortened half-life and low peak aminoglycoside concentrations. Retrospective studies suggest that ODA may be appropriate if higher milligram/kilogram doses are used. However, no prospective clinical trials in burn patients exist to confirm these findings. OBJECTIVE To determine the adequacy of once daily tobramycin dosed at 10mg/kg in adult burn patients. METHODS This prospective single dose pharmacokinetic clinical trial was conducted at the Ross Tilley Burn Centre. Patients with a total burn surface area (TBSA) of <20% and creatinine clearance ≥50mL/min were eligible. A first-order one compartment model was used to determine the pharmacokinetic profile from 3 or 5 tobramycin levels over a 24h period per patient. Monte Carlo simulation (MCS) was performed to determine the probability of target level attainment. RESULTS The mean percent TBSA, partial, and full thickness burn were 10%, 6%, and 4%, respectively. Nine of the ten patients recruited achieved peak concentrations of ≥20mg/L (mean of 29.4±5.7mg/L) and all patients had a trough level ≤0.5mg/L. The mean half-life, volume of distribution, and clearance were 2.58h, 0.33L/kg, and 7.40L/h, respectively. The MCS determined probability of attaining target peak concentrations with the 10mg/kg dose was 97%, which almost doubled that predicted with the usual 7mg/kg dose. CONCLUSION Burn patients with adequate renal function and <20% TBSA are candidates for ODA. Tobramycin half-life was similar to healthy, non-burn patients. The larger than normal volume of distribution supports the use of the higher empiric dose of 10mg/kg total body or adjusted weight in non-obese and obese patients, respectively, with further dose adjustment based on therapeutic drug monitoring.
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Affiliation(s)
- Colin Lee
- Sunnybrook Health Sciences Centre (SHSC), Department of Pharmacy, Canada; University of Toronto, Leslie Dan Faculty of Pharmacy, Canada
| | - Sandra A N Walker
- Sunnybrook Health Sciences Centre (SHSC), Department of Pharmacy, Canada; University of Toronto, Leslie Dan Faculty of Pharmacy, Canada; SHSC, Division of Infectious Diseases, Canada; SHSC, Sunnybrook Research Institute, Canada.
| | - Scott E Walker
- Sunnybrook Health Sciences Centre (SHSC), Department of Pharmacy, Canada; University of Toronto, Leslie Dan Faculty of Pharmacy, Canada
| | - Winnie Seto
- University of Toronto, Leslie Dan Faculty of Pharmacy, Canada; Hospital for Sick Children (HSC), Department of Pharmacy, Canada
| | - Andrew Simor
- SHSC, Division of Infectious Diseases, Canada; SHSC, Sunnybrook Research Institute, Canada; University of Toronto, Faculty of Medicine, Canada
| | - Marc Jeschke
- University of Toronto, Faculty of Medicine, Canada; SHSC, Ross Tilley Burn Centre, Canada
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9
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Abstract
LEARNING OBJECTIVES After studying this article, the participant should be able to: 1. Explain the epidemiology of severe burn injury in the context of socioeconomic status, gender, age, and burn cause. 2. Describe challenges with burn depth evaluation and novel methods of adjunctive assessment. 3. Summarize the survival and functional outcomes of severe burn injury. 4. State strategies of fluid resuscitation, endpoints to guide fluid titration, and sequelae of overresuscitation. 5. Recognize preventative measures of sepsis. 6. Explain intraoperative strategies to improve patient outcomes, including hemostasis, restrictive transfusion, temperature regulation, skin substitutes, and Meek skin grafting. 7. Translate updates in the pathophysiology of hypertrophic scarring into novel methods of clinical management. 8. Discuss the potential role of free tissue transfer in primary and secondary burn reconstruction. SUMMARY Management of burn-injured patients is a challenging and unique field for plastic surgeons. Significant advances over the past decade have occurred in resuscitation, burn wound management, sepsis, and reconstruction that have improved outcomes and quality of life after thermal injury. However, as patients with larger burns are resuscitated, an increased risk of nosocomial infections, sepsis, compartment syndromes, and venous thromboembolic phenomena have required adjustments in care to maintain quality of life after injury. This article outlines a number of recent developments in burn care that illustrate the evolution of the field to assist plastic surgeons involved in burn care.
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10
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Dou Y, Huan J, Guo F, Zhou Z, Shi Y. Pseudomonas aeruginosa prevalence, antibiotic resistance and antimicrobial use in Chinese burn wards from 2007 to 2014. J Int Med Res 2017; 45:1124-1137. [PMID: 28443385 PMCID: PMC5536433 DOI: 10.1177/0300060517703573] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Objective To assess the application of antibacterial agents, alongside pathogen prevalence and Pseudomonas aeruginosa drug resistance, with the aim of understanding the impact of inappropriate antibacterial use. Methods This retrospective study assessed bacteria from wounds, catheters, blood, faeces, urine and sputum of hospitalized patients in burn wards between 2007 and 2014. The intensity of use of antibacterial agents and resistance of P. aeruginosa to common anti-Gram-negative antibiotics were measured. Results Annual detection rates of Staphylococcus aureus were significantly decreased, whereas annual detection rates of P. aeruginosa and Klebsiella pneumoniae were significantly increased. Multidrug-resistant strains of P. aeruginosa were increased. The intensity of use of some anti-Gramnegative antibiotics positively correlated with resistance rates of P. aeruginosa to similar antimicrobials. Conclusion In burn wards, more attention should be paid to P. aeruginosa and K. pneumoniae. The use of ciprofloxacin, ceftazidime and cefoperazone/sulbactam should be limited to counter the related increase in resistance levels.
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Affiliation(s)
- Yi Dou
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Jingning Huan
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Feng Guo
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Zengding Zhou
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Yan Shi
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
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Hop MJ, Polinder S, van der Vlies CH, Middelkoop E, van Baar ME. Costs of burn care: A systematic review. Wound Repair Regen 2014; 22:436-50. [DOI: 10.1111/wrr.12189] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 04/01/2014] [Indexed: 11/30/2022]
Affiliation(s)
- M. Jenda Hop
- Association of Dutch Burn Centers; Burn Center; Maasstad Hospital; Rotterdam The Netherlands
- Department of Plastic, Reconstructive and Hand Surgery; MOVE Research Institute; VU University Medical Center; Amsterdam The Netherlands
| | - Suzanne Polinder
- Department of Public Health; Erasmus Medical Center; Rotterdam The Netherlands
| | | | - Esther Middelkoop
- Department of Plastic, Reconstructive and Hand Surgery; MOVE Research Institute; VU University Medical Center; Amsterdam The Netherlands
- Association of Dutch Burn Centers; Red Cross Hospital; Beverwijk The Netherlands
| | - Margriet E. van Baar
- Association of Dutch Burn Centers; Burn Center; Maasstad Hospital; Rotterdam The Netherlands
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12
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Antibacterial susceptibility of bacteria isolated from burns and wounds of cancer patients. JOURNAL OF SAUDI CHEMICAL SOCIETY 2014. [DOI: 10.1016/j.jscs.2011.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Langschmidt J, Caine PL, Wearn CM, Bamford A, Wilson YT, Moiemen NS. Hydrotherapy in burn care: a survey of hydrotherapy practices in the UK and Ireland and literature review. Burns 2013; 40:860-4. [PMID: 24332438 DOI: 10.1016/j.burns.2013.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 10/25/2013] [Accepted: 11/12/2013] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Hydrotherapy is widely used in burns management however there are risks associated with its use, in particular cross-infection. Data regarding indications and techniques in common use is deficient. This study aimed to investigate hydrotherapy practices in the UK and Ireland. METHODS A survey of the hydrotherapy practice of major burn care providers was performed by e mail and where necessary, follow up telephone contact. RESULTS The survey included 28 burn care providers. 27 reported using hydrotherapy. Only 11 (41%) had defined indication criteria with 4 (15%) implementing a specific protocol. Variations in hydrotherapy practice were seen. CONCLUSION Hydrotherapy is used nationwide, however considerable variation in practice exists. One area worthy of further consideration is the need for appropriate standards of infection control.
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Affiliation(s)
- Jenna Langschmidt
- Warwick Medical School, The University of Warwick, Coventry CV4 7AL, UK
| | - Paul L Caine
- University of Birmingham Medical School, Edgbaston, Birmingham B15 2TT, UK
| | - Christopher M Wearn
- Burns & Plastic Surgery Department, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham B15 2WB, UK
| | - Amy Bamford
- Burns & Plastic Surgery Department, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham B15 2WB, UK
| | - Yvonne T Wilson
- Burns & Plastic Surgery Department, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham B15 2WB, UK; Birmingham Children's Hospital NHS Foundation Trust, Steelhouse Lane, Birmingham B4 6NH, UK
| | - Naiem S Moiemen
- Burns & Plastic Surgery Department, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham B15 2WB, UK; Birmingham Children's Hospital NHS Foundation Trust, Steelhouse Lane, Birmingham B4 6NH, UK.
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Nichols DP, Caceres S, Caverly L, Fratelli C, Kim SH, Malcolm K, Poch KR, Saavedra M, Solomon G, Taylor-Cousar J, Moskowitz S, Nick JA. Effects of azithromycin in Pseudomonas aeruginosa burn wound infection. J Surg Res 2013; 183:767-76. [PMID: 23478086 DOI: 10.1016/j.jss.2013.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 01/29/2013] [Accepted: 02/01/2013] [Indexed: 02/01/2023]
Abstract
BACKGROUND Cutaneous thermal injuries (i.e., burns) remain a common form of debilitating trauma, and outcomes are often worsened by wound infection with environmental bacteria, chiefly Pseudomonas aeruginosa. MATERIALS AND METHODS We tested the effects of early administration of a single dose of azithromycin, with or without subsequent antipseudomonal antibiotics, in a mouse model of standardized thermal injury infected with P aeruginosa via both wound site and systemic infection. We also tested the antimicrobial effects of these antibiotics alone or combined in comparative biofilm and planktonic cultures in vitro. RESULTS In our model, early azithromycin administration significantly reduced wound and systemic infection without altering wound site or circulating neutrophil activity. The antimicrobial effect of azithromycin was additive with ciprofloxacin but significantly reduced the antimicrobial effect of tobramycin. This pattern was reproduced in biofilm cultures and not observed in planktonic cultures of P aeruginosa. CONCLUSION These data suggest that early administration of azithromycin following burn-related trauma and infection may reduce P aeruginosa infection and potential interactions with other antibiotics should be considered when designing future studies.
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Affiliation(s)
- David P Nichols
- Pulmonary Medicine Division, Department of Pediatrics, National Jewish Health, Denver, CO 80206, USA.
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15
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Kumar V, Sen MR, Nigam C, Gahlot R, Kumari S. Burden of different beta-lactamase classes among clinical isolates of AmpC-producing Pseudomonas aeruginosa in burn patients: A prospective study. Indian J Crit Care Med 2012. [PMID: 23188953 PMCID: PMC3506070 DOI: 10.4103/0972-5229.102077] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Pseudomonas aeruginosa is one of the most common pathogens causing infections in burns, and shows increasing resistance to β-lactam antibiotics by producing different classes of beta-lactamases. It is also not unusual to find a single isolate that expresses multiple β-lactamase enzymes, further complicating the treatment options. Thus, in this study, we aimed to determine the coexistence of different beta-lactamase enzymes in clinical isolates of P. aeruginosa in the burn ward. Materials and Methods: A total of 101 clinical isolates of P. aeruginosa from the burn ward were identified and tested for the presence of different beta-lactamase enzymes (extended spectrum beta lactamase (ESBL), Amp C and metallo β-lactamases (MBL) from October 2006 to May 2009. In vitro susceptibility pattern of antipseudomonal antibiotics was done by the Kirby Bauer disc diffusion method. Results: A total of 33 (32.7%) isolates were confirmed to be positive for AmpC beta-lactamase. Co-production of AmpC along with ESBL and MBL was reported in 24.5% and 45.5% isolates, respectively. A total of 12 (11.9%) isolates were resistant to three or more antibiotic classes (multidrug resistance). Imipenem and piperacillin/tazobactum showed high sensitivity, with 86.1% and 82.2%, respectively. Conclusion: This study reveals the high prevalence of multidrug- resistant P. aeruginosa producing beta-lactamase enzymes of different mechanisms in this region from burn patients. The emerging antimicrobial resistance in burn wound pathogens poses serious therapeutic challenge. Thus proper antibiotic policy and measures to restrict the indiscriminate use of cephalosporins and carbapenems should be taken to minimize the emergence of this multiple beta -lactamase producing pathogen.
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Affiliation(s)
- V Kumar
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
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16
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In vivo modeling of biofilm-infected wounds: A review. J Surg Res 2012; 178:330-8. [DOI: 10.1016/j.jss.2012.06.048] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/17/2012] [Accepted: 06/21/2012] [Indexed: 12/23/2022]
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17
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Bacterial cultures in burn patients’ mattresses. EUROPEAN JOURNAL OF PLASTIC SURGERY 2012. [DOI: 10.1007/s00238-012-0749-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Boekema BKHL, Pool L, Ulrich MMW. The effect of a honey based gel and silver sulphadiazine on bacterial infections of in vitro burn wounds. Burns 2012; 39:754-9. [PMID: 23036845 DOI: 10.1016/j.burns.2012.09.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/03/2012] [Accepted: 09/04/2012] [Indexed: 11/28/2022]
Abstract
Bacterial contamination remains a constant threat in burn wound care. Topical treatments to combat contaminations have good bactericidal effects but can have detrimental effects for the healing process. Treatments with for example silver can increase healing times. Honey based products can be a good alternative as it is antibacterial and patient-friendly. We evaluated the bactericidal and cytotoxic effects of a honey based gel and silver sulphadiazine in a human burn wound model with Pseudomonas aeruginosa. After adding 10(5)colony forming units of P. aeruginosa, topical treatments were applied on the burn wound models. After 2, 12, 24, 28 and 70 h, bacteria were dislodged and counted by plating dilutions. Cytotoxic effects were evaluated histologically in samples of burn wound models treated topically for 3 weeks, without bacteria. L-Mesitran Soft significantly reduced the bacterial load (5-log reduction) up to 24h but did not completely eliminate bacteria from the burn wounds. After Flammazine(®) treatment, only a few colony forming units were observed at all time points. In contrast, re-epithelialization was significantly reduced after application of Flammazine(®) compared to L-Mesitran Soft or control. This in vitro model of burn wound infection can be used to evaluate topical treatments. L-Mesitran Soft is a good alternative for treating burn wounds but the slightly lower bactericidal activity in the burn wound model warrants a higher frequency of application.
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Affiliation(s)
- B K H L Boekema
- Association of Dutch Burn Centres, PO Box 1015, 1940 EA Beverwijk, The Netherlands.
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Huzar TF, Cross JM. Ventilator-associated pneumonia in burn patients: a cause or consequence of critical illness? Expert Rev Respir Med 2012; 5:663-73. [PMID: 21955236 DOI: 10.1586/ers.11.61] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Infectious complications are a constant threat to thermally injured patients during hospitalizations and are a predominant cause of death. Most of the infections that develop in burn patients are nosocomial and of a pulmonary etiology. The bacteria that cause ventilator associated pneumonia (VAP) take advantage of the fact that uniquely among intensive care unit patients endotracheal intubation allows them a 'free' passage to the sterile lower airways; however, the combination of severe thermal injury (systemic immunosuppression) and inhalation injury (local immunosuppression and tissue injury) create an ideal environment for development of VAP. Thus, strategies directed at preventing and treating VAP in burn patients must address not only rapid extubation and VAP prevention bundles known to work in other intensive care unit populations, but therapies directed to more rapid wound healing and restoration of pulmonary patency.
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Affiliation(s)
- Todd F Huzar
- Department of Surgery, University of Texas Medical School, Houston, TX, USA.
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FAN PJ, YANG XH, XIAO MZ, LONG JH, LEI SR. Toll Like Receptor-4 Involved in The Mechanism of Hyperplastic Scarring via TGF-β*. PROG BIOCHEM BIOPHYS 2011. [DOI: 10.3724/sp.j.1206.2011.00057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Youssef D, Bailey B, El-Abbassi A, Vannoy M, Manning T, Moorman JP, Peiris AN. Healthcare costs of methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa infections in veterans: role of vitamin D deficiency. Eur J Clin Microbiol Infect Dis 2011; 31:281-6. [PMID: 21695580 DOI: 10.1007/s10096-011-1308-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 05/23/2011] [Indexed: 01/28/2023]
Abstract
Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections are frequently associated with hospitalization and increased healthcare costs. Vitamin D deficiency may contribute to increased costs for patients with these infections and there is evidence that vitamin D may have an antimicrobial role. To evaluate the role of vitamin D deficiency in the costs incurred with these infections, we studied the relationship of serum 25(OH)D levels to healthcare costs in veterans in the southeastern United States. Patients with both infections were vitamin D deficient to a similar extent and so were combined for further analysis. Vitamin D deficient patients had higher costs and service utilization than those who were not vitamin D deficient. Those with vitamin D deficiency had higher inpatient costs compared to the non-deficient group, and this difference was across most categories except for the number of inpatient hospitalizations or total number of days as an inpatient. Vitamin D deficiency was not significantly related to outpatient cost or service utilization parameters. We conclude that vitamin D deficiency is intimately linked to adverse healthcare costs in veterans with MRSA and P. aeruginosa infections. Vitamin D status should be assayed in patients with these infections.
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Affiliation(s)
- D Youssef
- Department of Internal Medicine, Division of Infectious Diseases, East Tennessee State University, Johnson City, TN, USA.
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23
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Benson MA, Komas SM, Schmalzer KM, Casey MS, Frank DW, Feix JB. Induced conformational changes in the activation of the Pseudomonas aeruginosa type III toxin, ExoU. Biophys J 2011; 100:1335-43. [PMID: 21354407 DOI: 10.1016/j.bpj.2011.01.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 01/07/2011] [Accepted: 01/25/2011] [Indexed: 02/07/2023] Open
Abstract
ExoU is a 74-kDa, water-soluble toxin injected directly into mammalian cells through the type III secretion system of the opportunistic pathogen, Pseudomonas aeruginosa. Previous studies have shown that ExoU is a Ca(2+)-independent phospholipase that requires a eukaryotic protein cofactor. One protein capable of activating ExoU and serving as a required cofactor was identified by biochemical and proteomic methods as superoxide dismutase (SOD1). In these studies, we carried out site-directed spin-labeling electron paramagnetic resonance spectroscopy to examine the effects of SOD1 and substrate liposomes on the structure and dynamics of ExoU. Local conformational changes within the catalytic site were observed in the presence of substrate liposomes, and were enhanced by the addition of SOD1 in a concentration-dependent manner. Conformational changes in the C-terminal domain of ExoU were observed upon addition of cofactor, even in the absence of liposomes. Double electron-electron resonance experiments indicated that ExoU samples multiple conformations in the resting state. In contrast, addition of SOD1 induced ExoU to adopt a single, well-defined conformation. These studies provide, to our knowledge, the first direct evidence for cofactor- and membrane-induced conformational changes in the mechanism of activation of ExoU.
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Affiliation(s)
- Marc A Benson
- Center for Infectious Disease Research, Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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24
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Wang J, Hori K, Ding J, Huang Y, Kwan P, Ladak A, Tredget EE. Toll-like receptors expressed by dermal fibroblasts contribute to hypertrophic scarring. J Cell Physiol 2011; 226:1265-73. [DOI: 10.1002/jcp.22454] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Nonantibiotic therapy for multidrug-resistant Pseudomonas aeruginosa in a patient with chronic burn wounds. Am J Med Sci 2010; 340:521-3. [PMID: 21119334 DOI: 10.1097/maj.0b013e3181f4c578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The authors report a special case of nonantibiotic therapy in a adolescent boy with chronically infected wounds induced by inappropriate use of antibiotics. The result of microbial cultures of the secretions on the wounds indicated that the infection of multidrug-resistant Pseudomonas aeruginosa was resistant to aminoglycoside and cephalosporin but sensitive to carbapenem and quinolones. We formulated a management strategy including daily hydrotherapy, thermal radiation therapy, balanced fluid and electrolytes and intermittent transfusion of blood products, but antibiotics were not used. Twenty-four days after his hospitalization, an autologous split-meshed skin grafting was successfully performed. He was followed up for 6 months after discharge; both lower extremities had an excellent functional recovery. The therapy introduced in this report may be beneficial for chronic infected wounds.
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Niven D, Fick G, Kirkpatrick A, Grant V, Laupland K. Cost and outcomes of nosocomial bloodstream infections complicating major traumatic injury. J Hosp Infect 2010; 76:296-9. [DOI: 10.1016/j.jhin.2010.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 06/10/2010] [Indexed: 11/29/2022]
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Rafla K, Tredget EE. Infection control in the burn unit. Burns 2010; 37:5-15. [PMID: 20561750 DOI: 10.1016/j.burns.2009.06.198] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 05/20/2009] [Accepted: 06/03/2009] [Indexed: 10/19/2022]
Abstract
The survival rates for burn patients have improved substantially in the past few decades due to advances in modern medical care in specialized burn centers. Burn wound infections are one of the most important and potentially serious complications that occur in the acute period following injury. In addition to the nature and extent of the thermal injury influencing infections, the type and quantity of microorganisms that colonize the burn wound appear to influence the future risk of invasive wound infection. The focus of medical care needs to be to prevent infection. The value of infection prevention has been acknowledged in organized burn care since its establishment and is of crucial importance. This review focuses on modern aspects of the epidemiology, diagnosis, management, and prevention of burn wound infections and sepsis.
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Affiliation(s)
- Karim Rafla
- Division of Plastic and Reconstructive Surgery and Critical Care, Department of Surgery, University of Alberta, University of Alberta, Edmonton, Alberta, Canada
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28
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Pseudomonas aeruginosa bacteraemia in burns patients: Risk factors and outcomes. Burns 2010; 36:1228-33. [PMID: 20965109 DOI: 10.1016/j.burns.2010.05.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 05/04/2010] [Accepted: 05/12/2010] [Indexed: 11/22/2022]
Abstract
INTRODUCTION We aimed to identify the risk factors for, and outcomes of Pseudomonas aeruginosa bacteraemia in adult burns patients. METHOD All adult burns patients who developed a Gram-negative bacteraemia over a period of 7 years were included. Retrospective data analysed included patient demographics, organisms cultured, antibiotic susceptibility patterns, isolation of P. aeruginosa in non-blood isolates, treatment, length of stay and mortality. RESULTS Forty-three patients developed a Gram-negative bacteraemia over the study period, 12 of whom had Pseudomonas bacteraemia during the course of their admission. In eight patients (18.6%) P. aeruginosa was the first Gram-negative isolated. The only factor predicting P. aeruginosa bacteraemia as a first episode (compared to another Gram-negative) was prior isolation of Pseudomonas at other sites (wound sites, urine or sputum). Overall length of stay was less in patients who developed P. aeruginosa as a first episode, mainly because of increased mortality in this group. Prior non-blood isolates of P. aeruginosa could have correctly predicted the sensitivity pattern of the strain of P. aeruginosa organism in 75% of patients who did not receive appropriate initial antibiotics. CONCLUSION Prior colonisation with P. aeruginosa predicts P. aeruginosa in blood cultures, as opposed to other Gram-negative bacteria. Clinicians should have a high index of suspicion for P. aeruginosa bacteraemia where a septic burns patient has a prior history of non-blood P. aeruginosa cultures. Empirical antibiotic regimes based on the antibiotic-sensitivity patterns of previous non-blood P. aeruginosa isolates in each patient should be given at the time blood cultures are taken.
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Dowd SE, Sun Y, Smith E, Kennedy JP, Jones CE, Wolcott R. Effects of biofilm treatments on the multi-species Lubbock chronic wound biofilm model. J Wound Care 2010; 18:508, 510-12. [PMID: 20081576 DOI: 10.12968/jowc.2009.18.12.45608] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To evaluate the efficacy of several biofilm effectors in inhibiting biofilm formation in an in vitro multi-species chronic wound biofilm model. METHOD The Lubbock Chronic Wound Biofilm (LCWB) model has been described in detail elsewhere. Pathogens used in the model are Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus. These are three of the most important species associated with biofilms. Here, the model was exposed to the following biofilm effectors: xylitol, salicylic acid, farnesol, erythritol and two proprietary, semi-solid, wound-dressing formulations currently under development (Sanguitec gels). RESULTS Biofilm formation was completely inhibited in the LCWB model following treatment with 20% xylitol, 10% erythritol, 1,000 microg/ml farnesol, 20mM salicylic acid or 0.1% of either of the two Sanguitec gel formulations. Salicylic acid specifically inhibited S. aureus (p<0.01) at 10mM and 20mM, consequently increasing the ratios of P. aeruginosa and E. faecalis within the biofilm. Xylitol had an increasing inhibitory effect on P. aeruginosa (p<0.01) at all concentrations evaluated. Erythritol had an inhibitory effect on P. aeruginosa and S. aureus growth (p<0.01) at over 5% concentrations. The inhibitory effect of both Sanguitec gel formulations was more broadly effective, with an increasingly inhibitory effect on all LCWB species (p<0.01). CONCLUSION The LCWB model provides a multi-species format with which to evaluate the effect of biofilm effectors on wound flora in a biofilm phenotype. These results suggest that different treatments can target specific populations within a biofilm. Salicylic acid preferentially targeted S. aureus, xylitol preferentially targeted P. aeruginosa, while erythritol preferentially targeted both P. aeruginosa and S. aureus. In contrast, the two Sanguitec gel formulations provided a broad, less preferential, inhibition of biofilm development. DECLARATION OF INTEREST Research and Testing Laboratory is a for-profit enterprise that develops molecular methods and performs service research work on biofilms. Sanguitec gel was developed by JPK and CEJ.
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Affiliation(s)
- S E Dowd
- US Department of Agriculture ARS Livestock Issues Research Unit, Lubbock, Texas, USA.
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Keen EF, Robinson BJ, Hospenthal DR, Aldous WK, Wolf SE, Chung KK, Murray CK. Prevalence of multidrug-resistant organisms recovered at a military burn center. Burns 2010; 36:819-25. [PMID: 20080354 DOI: 10.1016/j.burns.2009.10.013] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 09/28/2009] [Accepted: 10/14/2009] [Indexed: 11/15/2022]
Abstract
Infections caused by multidrug-resistant (MDR) pathogens are associated with significant morbidity and mortality in patients with burn injuries. We performed a 6-year antibiotic susceptibility records review from January 2003 to December 2008 to assess the prevalence of MDR isolates by pathogen at the US Army Institute of Surgical Research Burn Center. During the study period Acinetobacter baumannii (780 isolates [22%]) was the most prevalent organism recovered, followed by Pseudomonas aeruginosa (703 isolates [20%]), Klebsiella pneumoniae (695 isolates [20%]), and Staphylococcus aureus (469 isolates [13%]). MDR prevalence rates among these isolates were A. baumannii 53%, methicillin-resistant S. aureus (MRSA) 34%, K. pneumoniae 17% and P. aeruginosa 15%. Two isolates, 1 A. baumannii and 1 P. aeruginosa, were identified as resistant to all 4 classes of antibiotics tested plus colistin. A. baumannii isolates recovered from patients with burns greater than 30% of total body surface area (TBSA) were more likely to be MDR (61%) with no significant difference for P. aeruginosa and K. pneumoniae. A higher proportion of MDR P. aeruginosa isolates were recovered from respiratory specimens compared to blood specimens (24% vs. 9%) while the opposite was true for MRSA (35% vs. 54%). A comparison of A. baumannii recovered during hospitalization days 1-5 and 15-30 revealed higher MDR levels as length of stay increased (48% vs. 75%) while no significant trends were observed for P. aeruginosa and K. pneumoniae. A similar pattern was observed for MDR A. baumannii levels for the facility between 2003 and 2005 and 2006-2008 (39% vs. 70%), with no significant increase in MDR P. aeruginosa and MDR K. pneumoniae. Increasing antibiotic resistance patterns of the most prevalent isolates recovered during extended hospitalization, impact of % TBSA and other clinical parameters may affect empirical antimicrobial therapy and patient management decisions during treatment.
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Affiliation(s)
- Edward F Keen
- San Antonio Military Medical Center, Brooke Army Medical Center, 3851 Roger Brooke Drive, Fort Sam Houston, TX 78234, USA
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Fms-like tyrosine kinase-3 ligand alters antigen-specific responses to infections after severe burn injury. Shock 2010; 32:435-41. [PMID: 19752689 DOI: 10.1097/shk.0b013e31819e2937] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Burn patients are susceptible to opportunistic infections partly because of decreased immune functions, especially TH1-driven antigen-specific responses, which are regulated by dendritic cells. The dendritic cell growth factor, fms-like tyrosine kinase-3 ligand (FL), has been shown to increase resistance to Pseudomonas aeruginosa, in a dendritic cell-dependent manner, in a mouse model of burn wound infection. The specific mechanisms of protection are not known. This study tested the hypothesis that FL can enhance production of P. aeruginosa-specific antibodies after burn wound infection. Mice that had been previously exposed to P. aeruginosa were infected after burn injury by wound inoculation or challenged by intraperitoneal injection of heat-killed P. aeruginosa. In response to wound infection, FL treatments enhanced bacterial clearance and induced a shift from immunoglobulin (Ig) M toward IgG and IgA. However, serum levels of neither P. aeruginosa-specific antibodies nor interferon gamma (IFN-gamma) were significantly increased by FL, possibly because of decreased systemic exposure to bacteria. After challenge with heat-killed bacteria, which ensured equal exposures, FL-treated mice produced significantly greater levels of P. aeruginosa-specific IgG2a, which correlated with an increase in serum levels of interferon gamma and enhanced opsonization capacity. IL-12, IL-10, and transforming growth factor beta were significantly increased in FL-treated mice, regardless of the type of challenge. These findings indicate that FL treatments after burn injury enhance cytokine responses to recall antigens and increase bacterial clearance. In addition, through its ability to promote TH1-associated antigen-specific responses, FL may have potential as an immunotherapy to enhance adaptive immunity after severe burn injury.
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A sensitive fluorescence-based assay for the detection of ExoU-mediated PLA(2) activity. Clin Chim Acta 2009; 411:190-7. [PMID: 19900431 DOI: 10.1016/j.cca.2009.10.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 10/27/2009] [Accepted: 10/30/2009] [Indexed: 11/24/2022]
Abstract
BACKGROUND Pseudomonas aeruginosa is an opportunistic pathogen that causes disease in immunocompromised individuals, burn victims, and cystic fibrosis patients. Strains that secrete ExoU induce host cell lysis and damage epithelial tissue, which can lead to severe outcomes including sepsis and mortality. ExoU is classified as an A2 phospholipase (PLA(2)) and activity is dependent on the eukaryotic protein, superoxide dismutase 1 (SOD1). METHODS A sensitive and low background in vitro fluorescence-based assay was developed to detect ExoU activity using the fluorogenic substrate, PED6. RESULTS The optimized assay enabled us to perform the first kinetic evaluation of the activation of ExoU (apparent K(m) of 13.2+/-1.5mumol/l PED6 and an apparent V(max) of 42nmol/min/mg). An inhibitor study using the inhibitor, methyl arachidonyl fluorophosphonate (MAFP), yielded an IC(50) of 13.8+/-1.1nmol/l and validated the use of high-throughput inhibitor screens using the assay. Most notably, the in vitro fluorescence-based activity assay was sensitive enough to detect catalytically active ExoU injected into eukaryotic cells. DISCUSSION The use of the fluorescence-based activity assay to study the mechanism of ExoU activation may lead to the development of potential therapeutics to reduce P. aeruginosa-associated mortality.
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Abstract
One of the hallmarks of bacterial survival is their ability to adapt rapidly to changing environmental conditions. Niche adaptation is a response to the signals received that are relayed, often to regulators that modulate gene expression. In the post-genomic era, DNA microarrays are used to study the dynamics of gene expression on a global scale. Numerous studies have used Pseudomonas aeruginosa--a Gram-negative environmental and opportunistic human pathogenic bacterium--as the model organism in whole-genome transcriptome analysis. This paper reviews the transcriptome studies that have led to immense advances in our understanding of the biology of this intractable human pathogen. Comparative analysis of 23 P. aeruginosa transcriptome studies has led to the identification of a unique set of genes that are signal specific and a core set that is differentially regulated. The 303 genes in the core set are involved in bacterial homeostasis, making them attractive therapeutic targets.
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Affiliation(s)
- Deepak Balasubramanian
- Department of Biological Sciences, College of Arts and Science, Florida International University, Miami, FL 33199, USA
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Bohannon JK, Cui W, Toliver-Kinsky T. Endogenous Fms-like tyrosine kinase-3 ligand levels are not altered in mice after a severe burn and infection. BMC Immunol 2009; 10:47. [PMID: 19715582 PMCID: PMC2744912 DOI: 10.1186/1471-2172-10-47] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 08/28/2009] [Indexed: 01/14/2023] Open
Abstract
Background Fms-like tyrosine kinase-3 ligand (Flt3L) is a hemopoietic cytokine and dendritic cell (DC) growth factor that promotes the proliferation and differentiation of progenitor cells into DCs. We have previously found that treatment of severely burned mice with recombinant Flt3L significantly enhances DC production and bacterial clearance from infected burn wounds, and increases global immune cell activation and survival in response to a burn wound infection. These significant benefits of Flt3L treatment after burn injury have prompted the question of whether or not severe burn injury induces deficits in endogenous Flt3L levels that could affect DCs and subsequent responses to infection. Results To address this, male BALB/c mice received a 30% total body surface area scald burn. Blood, spleens, and wound-draining lymph nodes were harvested at various time-points after injury. Some mice received a wound inoculation with P. aeruginosa. Murine Flt3L and G-CSF levels were measured by ELISA. Burn injury had no significant effect on Flt3L levels at any post-burn time-point examined compared to normal Flt3L levels in the sera, spleen, or lymph nodes. Additionally, Flt3L levels in the sera, spleen, and lymph nodes were not significantly altered when wounds were inoculated on the day of burn injury or at post-burn time points examined. Alternatively, levels of G-CSF were increased in response to burn injury and burn wound infection. Additionally, DC numbers and functions were not altered following burn injury alone. There was no significant difference between the number of DCs in the spleens of sham-injured mice and mice at 5 days after burn injury. When naïve T cells from sham-injured mice were co-cultured with DCs from either sham- or burn-injured mice, IFN-γ production was similar, however, IFN-γ levels produced by T cells harvested from burn-injured mice were significantly lower than those produced by T cells from sham mice, regardless of which DC group, sham or burn, was used in the coculture. Conclusion These data suggest that the beneficial effects of Flt3L treatments after burn injury are not due to correction of a burn-associated Flt3L deficiency but rather, are likely due to supplementary stimulation of DC production and immune responses to infection.
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Affiliation(s)
- Julia K Bohannon
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA.
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Ullah F, Malik SA, Ahmed J. Antimicrobial susceptibility and ESBL prevalence in Pseudomonas aeruginosa isolated from burn patients in the North West of Pakistan. Burns 2009; 35:1020-5. [PMID: 19501980 DOI: 10.1016/j.burns.2009.01.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Accepted: 01/15/2009] [Indexed: 10/20/2022]
Abstract
Pseudomonas aeruginosa is one of the most prevalent pathogen in burn infections. Infections with P. aeruginosa are associated with higher mortality rate and antibiotic costs in hospitalized patients. These bacteria also produce enzymes called Expanded Spectrum Beta-Lactamases (ESBL) which render penicillins and cephalosporins inactive. The aim of this study was to assess the antimicrobial susceptibility pattern and prevalence of ESBL in P. aeruginosa in Peshawar, North West of Pakistan. During 2005-2006, one hundred and six P. aeruginosa isolates were collected from burn patients at a tertiary care hospital. Antibiotic susceptibility testing and ESBL detection were carried out according to Clinical Laboratory and Standards Institute (CLSI) criteria. Eighteen antibiotics were tested in this study. A total of 38 (35.85%) isolates were found to be ESBL producers. Thirty one (29.24%) isolates were resistant to 3 or more antibiotics (multidrug resistance). Meropenem and imipenem showed high potency with 99% and 96% isolates being susceptible respectively. Susceptibility to amikacin was 70%; gentamicin 25%; ciprofloxacin 49%; enoxacin 47%; gatifloxacin 42%; doxycycline 21% and to co-trimoxazole only 16%. This study reveals that P. aeruginosa isolated from burns in this region are multidrug resistant and produce ESBL in large proportions.
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Affiliation(s)
- Farhat Ullah
- Department of Biochemistry/Molecular Biology, Quaid-i-Azam University, Islamabad, Pakistan.
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Tang A, Marquart ME, Fratkin JD, McCormick CC, Caballero AR, Gatlin HP, O'Callaghan RJ. Properties of PASP: a Pseudomonas protease capable of mediating corneal erosions. Invest Ophthalmol Vis Sci 2009; 50:3794-801. [PMID: 19255155 DOI: 10.1167/iovs.08-3107] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To analyze PASP in terms of its gene distribution and expression, its corneal pathologic effects, its enzymatic properties, and the protectiveness of the immune response to this protease. METHODS Twenty-five strains of P. aeruginosa were analyzed for the PASP gene and secreted protein by PCR and Western blot analysis, respectively. Active recombinant (r)PASP (10 microg/20 microL) or heat-inactivated rPASP was intrastromally injected into rabbit corneas. Pathologic changes were monitored by slit lamp examination (SLE) and histopathology. Purified rPASP was assayed for cleavage of collagens and susceptibility to TLCK. Rabbit antibody to rPASP was produced and tested for enzyme inactivation, and actively immunized rabbits were challenged by intrastromal injection of active rPASP (5 microg). RESULTS All 25 strains of P. aeruginosa analyzed were positive for the PASP gene and protein. SLE scores of eyes injected with active rPASP were significantly higher than control eyes at all postinjection times (PI; P <or= 0.004). Histopathologic studies documented the destruction of the corneal epithelial layer and portions of the corneal stroma at 9 hours PI, and polymorphonuclear (PMN) leukocyte infiltration into the cornea by 24 hours after active rPASP injection. PASP cleaved type I and IV collagens and was susceptible to TLCK inhibition. PASP was present in the cytoplasm and periplasm, but only secreted PASP was enzymatically active. A high antibody titer (ELISA titer >or= 10,000) was produced, but this antibody did not protect against active rPASP challenge. CONCLUSIONS PASP is a commonly produced Pseudomonas protease that can cleave collagens and cause corneal erosions.
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Affiliation(s)
- Aihua Tang
- Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Bohannon J, Cui W, Cox R, Przkora R, Sherwood E, Toliver-Kinsky T. Prophylactic treatment with fms-like tyrosine kinase-3 ligand after burn injury enhances global immune responses to infection. THE JOURNAL OF IMMUNOLOGY 2008; 180:3038-48. [PMID: 18292526 DOI: 10.4049/jimmunol.180.5.3038] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Severely burned patients are susceptible to infections with opportunistic organisms due to altered immune responses and frequent wound contamination. Immunomodulation to enhance systemic and local responses to wound infections may be protective after burn injury. We previously demonstrated that pretreatments with fms-like tyrosine kinase-3 (Flt3) ligand (Flt3L), a dendritic cell growth factor, increase the resistance of mice to a subsequent burn injury and wound infection by a dendritic cell-dependent mechanism. This study was designed to test the hypothesis that Flt3L administration after burn injury decreases susceptibility to wound infections by enhancing global immune cell activation. Mice were treated with Flt3L after burn injury and examined for survival, wound and systemic bacterial clearance, and immune cell activation after wound inoculation with Pseudomonas aeruginosa. To gain insight into the local effects of Flt3L at the burn wound, localization of Langerhans cells was examined. Mice treated with Flt3L had significantly greater numbers of CD25-expressing T cells and CD69-expressing T and B cells, neutrophils, and macrophages after, but not before, infection. Overall leukocyte apoptosis in response to infection was decreased with Flt3L treatment. Survival and local and systemic bacterial clearance were enhanced by Flt3L. Langerhans cells appeared in the dermis of skin bordering the burn wound, and further increased in response to wound infection. Flt3L augmented the appearance of Langerhans cells in response to both injury and infection. These data suggest that dendritic cell enhancement by Flt3L treatments after burn injury protects against opportunistic infections through promotion of local and systemic immune responses to infection.
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Affiliation(s)
- Julia Bohannon
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555-0591, USA
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Dowd SE, Sun Y, Secor PR, Rhoads DD, Wolcott BM, James GA, Wolcott RD. Survey of bacterial diversity in chronic wounds using pyrosequencing, DGGE, and full ribosome shotgun sequencing. BMC Microbiol 2008; 8:43. [PMID: 18325110 PMCID: PMC2289825 DOI: 10.1186/1471-2180-8-43] [Citation(s) in RCA: 525] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 03/06/2008] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Chronic wound pathogenic biofilms are host-pathogen environments that colonize and exist as a cohabitation of many bacterial species. These bacterial populations cooperate to promote their own survival and the chronic nature of the infection. Few studies have performed extensive surveys of the bacterial populations that occur within different types of chronic wound biofilms. The use of 3 separate16S-based molecular amplifications followed by pyrosequencing, shotgun Sanger sequencing, and denaturing gradient gel electrophoresis were utilized to survey the major populations of bacteria that occur in the pathogenic biofilms of three types of chronic wound types: diabetic foot ulcers (D), venous leg ulcers (V), and pressure ulcers (P). RESULTS There are specific major populations of bacteria that were evident in the biofilms of all chronic wound types, including Staphylococcus, Pseudomonas, Peptoniphilus, Enterobacter, Stenotrophomonas, Finegoldia, and Serratia spp. Each of the wound types reveals marked differences in bacterial populations, such as pressure ulcers in which 62% of the populations were identified as obligate anaerobes. There were also populations of bacteria that were identified but not recognized as wound pathogens, such as Abiotrophia para-adiacens and Rhodopseudomonas spp. Results of molecular analyses were also compared to those obtained using traditional culture-based diagnostics. Only in one wound type did culture methods correctly identify the primary bacterial population indicating the need for improved diagnostic methods. CONCLUSION If clinicians can gain a better understanding of the wound's microbiota, it will give them a greater understanding of the wound's ecology and will allow them to better manage healing of the wound improving the prognosis of patients. This research highlights the necessity to begin evaluating, studying, and treating chronic wound pathogenic biofilms as multi-species entities in order to improve the outcomes of patients. This survey will also foster the pioneering and development of new molecular diagnostic tools, which can be used to identify the community compositions of chronic wound pathogenic biofilms and other medical biofilm infections.
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Affiliation(s)
- Scot E Dowd
- United States Department of Agriculture ARS Livestock Issues Research Unit, Lubbock, TX, USA.
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Abstract
Bacterial pathogens utilize toxins to modify or kill host cells. The bacterial ADP-ribosyltransferases are a family of protein toxins that covalently transfer the ADP-ribose portion of NAD to host proteins. Each bacterial ADP-ribosyltransferase toxin modifies a specific host protein(s) that yields a unique pathology. These toxins possess the capacity to enter a host cell or to use a bacterial Type III apparatus for delivery into the host cell. Advances in our understanding of bacterial toxin action parallel the development of biophysical and structural biology as well as our understanding of the mammalian cell. Bacterial toxins have been utilized as vaccines, as tools to dissect host cell physiology, and more recently for the development of novel therapies to treat human disease.
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Affiliation(s)
- Qing Deng
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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