1/19. Native valve infective endocarditis: what is the optimal timing for surgery?IE remains a dreaded disease masquerading under a myriad of presentations in an evolving epidemiological environment. In our continuing endeavor against this deadly disease, echocardiography has evolved into an indispensable diagnostic tool to define structural complications and guide therapy. Timing of surgical intervention for IE remains a subject of intense debate and depends on the cardiac and systemic complications of the infection, the virulence of the organism, and the responsiveness to medical therapy. A judicious agreement among cardiologist, cardiovascular surgeon, and infectious disease specialist should define whether surgical intervention is warranted and, if so, the optimal timing. Further optimization of guidelines will help in the diagnosis and treatment of endocarditis but will never be a substitute for sound judgment and experience.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
2/19. treatment failure due to methicillin-resistant staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin.We report the first instance in australia of treatment failure due to a strain of methicillin-resistant staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin--heteroresistant vancomycin-intermediate S. aureus (hVISA). The infection occurred in a 41-year-old man with multiple risk factors. No transmission of the organism to other patients or the environment was detected. This case may herald the beginning of a new phase of staphylococcal resistance in australia.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
3/19. Infected endovascular graft secondary to coil embolization of endoleak: a demonstration of the importance of operative sterility.A 60-year-old male underwent endovascular repair of a 5.4-cm enlarging abdominal aortic aneurysm with intraoperative recognition of a type I endoleak. The endoleak was demonstrated to be arising from the left limb of the bifurcated prosthesis. An intravascular stent was placed in the limb near the origin of the common iliac artery and it appeared that the endoleak had sealed. However, 1 month after operation a CT scan demonstrated a persistent, substantial size endoleak without aneurysm enlargement. Coil embolization of the endoleak was undertaken in the interventional radiology suite with apparent satisfactory result. Four days after embolization the patient developed abdominal pain and after 8 days fever and leukocytosis developed. Two weeks after embolization an abdominal CT and indium scan revealed an infected endovascular graft. By CT, the posterior wall of the aneurysm was destroyed and a peri-graft fluid collection with gas was present at the location of the coils. The patient was treated with graft and coil excision and autologous vein reconstruction. Endoluminal prostheses can be contaminated at the time of operative placement. However, an additional source of endoluminal graft infection can arise from secondary endovascular procedures for endoleaks and other graft complications. Since we began placing endovascular grafts at our institution in 1993, most coil embolizations have been performed in the interventional radiology suite. This experience of coil-induced infection causes us to consider performing this type of secondary intervention in the operating room environment.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
4/19. An outbreak of legionella longbeachae infection in an intensive care unit?During a nine-day period, five patients in a 14-bed intensive care unit (ICU) were shown to have seroconverted with a four-fold or greater rise in serum antibody titre to legionella longbeachae serogroup 1. A further two patients were observed to have high titres consistent with previous exposure but earlier serum samples were not available for comparison. No patients had antibody responses to legionella pneumophila serogroups 1 and 2. L. longbeachae was not cultured from respiratory secretions from patients or from the environment within the unit. Legionella anisa was recovered from one cooling tower on the ninth floor of the tower block. The ICU is located on the first floor of the same tower and receives external air from two vents, one on the eastern and the other on the western aspect. All patients with serological evidence of L. longbeachae infection were concomitantly infected with multiresistant Staphylococcus aureus, and were located in bays on the eastern side of the unit. A large pigeon nest was discovered within 1-2 m of the eastern vent. Following removal of the birds' nest, no further cases were seen on routine screening of all patients within the unit over the next eight weeks. Alternatively, seroconversion may have been related to demolition of the adjacent nine-storey nurses home. This was begun one month before the first case was diagnosed and was completed four months later. The periodic northerly winds could have carried legionellae from the demolition site directly over the block housing the ICU and may have concentrated them near the eastern air vent. All patients had pneumonia, which was probably multifactorial in origin. There is some uncertainty whether the serological responses seen were an epiphenomenon or were truly indicative of infection with L. longbeachae.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
5/19. Sentinel cases of community-acquired methicillin-resistant staphylococcus aureus onboard a naval ship.methicillin-resistant staphylococcus aureus (MRSA) is emerging as a community-acquired organism. A number of recent reports have documented its involvement in a variety of infections in which no risk factors for nosocomial transmission are present. This report presents the initial cases of a MRSA outbreak on a U.S. Navy ship. Each patient failed traditional antibiotic therapy and one required hospitalization. Their presentations evolved simultaneously and proved to be sentinel cases of an outbreak of cutaneous MRSA infections. The events of this outbreak emphasize the growing need to consider the prevalence of resistant organisms in outpatient settings, as well as the impact that infections from resistant organisms might have on the combat readiness of a military unit. Recommendations addressing infection-control guidelines for MRSA within close-quarter environments of healthy adults, such as military units, need to be developed and existing infection-control measures need to be regularly emphasized.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
6/19. Infectious keratitis after photorefractive keratectomy.PURPOSE: To elucidate risk factors, microbial culture results, and visual outcomes for infectious keratitis after photorefractive keratectomy (PRK). DESIGN: Multicenter, retrospective chart review, case report, and literature review. methods: The records of 12 patients with infectious keratitis after PRK were reviewed. MAIN OUTCOME MEASURES: Causative organism, response to medical treatment, and visual outcome. RESULTS: Infectious keratitis developed in 13 eyes of 12 patients after PRK. Organisms cultured were Staphylococcus aureus (n = 5), including a bilateral case of methicillin-resistant staphylococcus aureus; staphylococcus epidermidis (n = 4); streptococcus pneumoniae (n = 3); and Streptococcus viridans (n = 1). Four patients manipulated their contact lenses, and 2 patients were exposed to nosocomial organisms while working in a hospital environment. Prophylactic antibiotics used were tobramycin (nine cases), polymyxin b-trimethoprim (three cases), and ciprofloxacin (one case). Final best spectacle-corrected visual acuity ranged from 20/20 to 20/100. CONCLUSIONS: Infectious corneal ulceration is a serious potential complication of PRK. Gram-positive organisms are the most common pathogens. antibiotic prophylaxis should be broad spectrum and should include gram-positive coverage.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
7/19. Bilateral methicillin-resistant staphylococcus aureus keratitis in a medical resident following an uneventful bilateral photorefractive keratectomy.PURPOSE: To present a case of bilateral methicillin-resistant staphylococcus aureus (MRSA) keratitis after photorefractive keratectomy (PRK). methods: Retrospective chart review.RESULTS A 26-year-old female internal medicine resident underwent an uneventful bilateral PRK. After the procedure, the patient was fit with a bandage contact lens and was prescribed tobramycin 0.3%, fluorometholone 0.1%, and diclofenac sodium 0.1% four times per day. Postoperatively, corneal ulcers were noted in each eye, and the patient was referred for a consultation. Gram stain showed gram-positive cocci. The patient immediately started using vancomycin, 35 mg/mL every half hour, and ofloxacin 0.3% every hour around the clock. Forty-eight hours later, corneal and lid cultures were positive for MRSA. Three months after the infection, there was approximately 40% corneal thinning in the right eye and 10% thinning in the area of the corneal ulceration of the left eye. The patient is awaiting corneal transplantation of the right eye. CONCLUSIONS: To our knowledge, this represents the first reported case of bilateral MRSA keratitis after PRK. Methicillin-resistant S. aureus is a potentially serious infectious agent after PRK and may be associated with exposure to a hospital setting. For patients who have had extensive exposure to a hospital environment and are undergoing ocular surgery, we recommend prophylaxis against MRSA. To treat a possible MRSA keratitis, we suggest starting a fourth-generation topical fluoroquinolone every 30 minutes, alternating it with vancomycin 50 mg/mL every 30 minutes, and discontinuing steroid use. A high degree of suspicion coupled with rapid and appropriate treatment may result in improved visual recovery.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
8/19. Long-term carriage, and transmission of methicillin-resistant staphylococcus aureus after discharge from hospital.The purpose of this study was to determine whether patients who become carriers of methicillin-resistant staphylococcus aureus (MRSA) during their stay in hospital, remain colonized after discharge. Thirty-six patients colonized with MRSA during one of three outbreaks at Utrecht University Hospital (1986-89) were screened 2 or 3 years after they had become carriers. patients were also interviewed to determine factors contributing to persistent carriage, such as antibiotics, re-admissions to the hospital, presence of skin lesions and chronic diseases. At the same time transmission of MRSA to family members was determined. The epidemic MRSA strain was still found in three patients (8%). One was a cystic fibrosis patient who had had frequent re-admissions to the hospital and had received several course of antibiotic treatment. Both of the other patients had skin lesions: a fistula and a colostomy respectively. None of the 44 family members of the patients was colonized or infected with MRSA. We conclude that long-term MRSA carriage occurs with low frequency and is comparable to persistent carriage of methicillin-sensitive Staphylococcus aureus (MSSA). Transmission of MRSA to healthy individuals in an antibiotic-free environment is a rare event.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
9/19. mycobacterium abscessus and other nontuberculous mycobacteria: evolving respiratory pathogens in cystic fibrosis: a case report and review.cystic fibrosis (CF) is a risk factor for the development of nontuberculous mycobacteria (NTM) infection. prevalence of these organisms varies from center to center with the predominance of affected patients being in the adult population. The difficulty in diagnosing NTM infection in CF involves the overlap between signs and symptoms of underlying CF lung disease with its variable pathogens and the signs and symptoms attributable to pulmonary disease caused by NTM. Bacterial overgrowth, especially with pseudomonas aeruginosa, is problematic, leading to the difficulty in recovering mycobacteria from sputum. There is varying opinion whether the presence of NTM in pulmonary secretions of patients with CF indicates infection or colonization from an environmental organism. This report describes a 14-year-old asymptomatic female patient with CF with minimal bronchiectasis on high-resolution computed tomography scan of the chest who clinically deteriorated over the next 29 months after acquiring mycobacterium abscessus to the point of being listed for lung transplantation. As more is discovered about NTM, the pathogenicity and virulence of these organisms should be considered in the setting of CF and treated.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
10/19. Bacterial biofilm formation on a human cochlear implant.OBJECTIVE: To report the characteristics of a bacterial biofilm from the surface of a cochlear implant. BACKGROUND: Bacterial biofilm formation on implanted devices causes intractable infections and device extrusions necessitating device removal, with loss of function. More information is needed about biofilm characteristics and interactions with the implant surface before better treatments can be designed. STUDY DESIGN: A retrospective case review was combined with a descriptive histological study of the surface of an otologic device. methods: The receiver/stimulator device removed from a cochlear implant patient because of intractable infection and partial device extrusion was fixed and processed for microscopic examination. Its surface and the material present on its surface were analyzed using light and electron microscopy, focusing on surface texture, cell types, and bacteria species and extracellular polymeric substances present within the biofilm. RESULTS: Stereomicroscopic examination revealed extracellular polymeric substances, pinkish yellow in color, with spheres of uniform size scattered throughout, indicative of a biofilm containing Staphylococcus aureus. Biofilm density was greatest in depressions on the surface of the implant. Cross-sectional analysis revealed bacteria interspersed with polymorphonuclear leukocytes. Scanning electron microscopic examination demonstrated an amorphous layer of extracellular polymeric substances containing small filaments, bacteria, and inflammatory cells. Only Staphylococcus aureus was detected. CONCLUSION: Cochlear implant material can provide a surface for bacterial biofilm formation. Impressions can provide an environment conducive to biofilm establishment and growth, ultimately necessitating device removal, with loss of implant function. Biofilm characterization should aid in design of cochlear implant devices less susceptible to biofilm formation.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
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