Bacteria aerosol spread and wound bacteria reduction with different methods for wound debridement in an animal model

Debridement is essential in wound treatment to remove necrotic tissue and wound bacteria but may lead to bacteria spread by aerosolization. This study investigated the wound bacterial reduction and bacterial transmission induced by debridement using curette, plasma-mediated bipolar radiofrequency ablation (Coblation®) or hydrodebridement (Versajet®). Full thickness dermal wounds in porcine joint specimens inoculated with S. aureus were debrided with curette, Coblation, Versajet, or were left untreated. During and after debridement, aerosolized bacteria were measured and to assess wound bacterial load, quantitative swab samples were taken from each wound. Only Coblation was able to reduce the bacterial load of the wound significantly. Versajet debridement resulted in a significant bacterial aerosolization, but this was not the case with Coblation and curette debridement. This study shows that Coblation is a promising wound debridement method, which effectively reduces the wound bed bacterial load without the risk of bacterial aerosolization.

Isolation of Leclercia adecarboxylata from a wound infection after exposure to hurricane-related floodwater

A man in his early 80s presented to our emergency department with painless redness and swelling in his right leg. One week prior, he cleaned up floodwater in his basement after Hurricane Irene passed the Mid-Atlantic region of the USA in August 2011. Physical examination included large purple bullae and raised concern for necrotising fasciitis. Wound culture revealed a polymicrobial infection including Leclercia adecarboxylata.

Multidrug-resistant organisms in military wounds from Iraq and Afghanistan

Mortality from battlefield wounds has historically declined, thanks to better surgical management, faster transport of casualties, and improved antibiotics. Today, one of the major challenges facing U.S. military caregivers is the presence of multidrug-resistant organisms in orthopaedic extremity wounds. The most frequently identified resistant strains of bacteria are Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter calcoaceticus-baumannii complex. Overuse of broad-spectrum antibiotics may be an important factor in building resistant strains. Acinetobacter infections appear to hospital-acquired and not from an initial colonization of the injury. More research is required to give military physicians the tools they require to reduce the infection rate and defeat multidrug-resistant organisms.

Study of the environmental effect of a commercial wound cleanser used with different mechanical forces

Important improvements have been made in wound care over the last decade. However, few data are available on the influence that these have outside their intended use. This study aimed to clarify the effects of the use of wound cleansers on bacterial contamination of the immediate surroundings. Little evidence was found from either laboratory or clinical settings that wound-derived micro-organisms become airborne during wound cleansing. Bacterial dispersion around wounds may be attributed to general activity rather than wound cleansing. If simple precautions are taken, risks for personnel and patients in hospitals and consultation rooms during wound cleansing can be minimized.

Pseudomonas infections in the thermally injured patient

Pseudomonas aeruginosa, remains a serious cause of infection and septic mortality in burn patients, particularly when nosocomially acquired. A prototypic burn patient who developed serious nosocomially acquired Pseudomonas infection is described as an index case which initiated investigations and measures taken to identify the source of the infection. The effect of changes in wound care to avoid further nosocomial infections was measured to provide data on outcome and cost of care. The bacteriology of Pseudomonas is reviewed to increase the burn care providers understanding of the behaviour of this very common and serious pathogen in the burn care setting, before reviewing the approach to detection of the organism and treatment both medically and surgically. After controlling the nosocomial spread of Pseudomonas in our burn unit, we investigated the morbidity and mortality associated with nosocomial infection with an aminoglycoside resistant Pseudomonas and the associated costs compared to a group of case-matched control patients with similar severity of burn injury, that did not acquire resistant Pseudomonas during hospitalization at our institution. We found a significant increase in the mortality rate in the Pseudomonas group compared to controls. The morbidity in terms of length of stay, ventilator days, number of surgical procedures, and the amount of blood products used were all significantly higher in the Pseudomonas group compared to controls. Costs associated with antibiotic requirements were also significantly higher in the Pseudomonas group. Despite this increased resource consumption necessary to treat Pseudomonas infections, these efforts did not prevent significantly higher mortality rates when compared to control patients who avoided infection with the resistant organism. Thus, in addition to the specific measures required to identify and treat nosocomial Pseudomonas infections in burn patients, prevention of infection through modification of treatment protocols together with continuous infection control measures to afford early identification and eradication of nosocomial Pseudomonas infection are critical for cost-effective, successful burn care.

[A case of zoonosis associated with Streptococcus equi ssp. zooepidemicus]

A sexagenarian couple operating a dairy farm, where there were also many horses, suffered a severe respiratory infection associated with the bacterium Streptococcus equi ssp. zooepidemicus. The investigation revealed that the source of infection was due to contacts with a horse having an infected wound from which we isolated this zoonotic agent.

[Highly resistant pathogens in patients with diabetic foot syndrome with special reference to methicillin-resistant Staphylococcus aureus infections]

BACKGROUND AND OBJECTIVE

Patients with diabetic foot infection (DFI) have a high rate of infection, up to 40%, with methicillin-resistant Staph. aureus (MRSA). Having noticed a definite increase of such patients in our special unit, we initiated a drastic change of hygienic measures and here report the results.

PATIENTS AND METHODS

788 patients with DFI (mean age 67.3 [32-90] years, 62% males) were admitted between 1.1.1999 and 31.7.2000. Before 31.7.1999, the following hygienic measures had been in place: cohort isolation, protective closing, implementation of general hygienic rules. Since 1.8.1999, modified measures have been undertaken: primary single-patient isolation, concentration in one ward of all patients with MRSA, medical care only by trained personnel, admission of patients only after microbiological results were known or primary solitary isolation. Algorithms were used for the transmission of all necessary information.

RESULTS

MRSA was demonstrated in 64 patients. The number of infections during the hospital stay, before and after the change of hygienic measures were 9 (27%) and 2 patients (8%), respectively. The sites of MRSA colonisation and proven eradication were: nasopharynx only, 3 with 67% eradication; MRSA in a wound, 25 with 28% eradication. In comparison to the yearly statistic on wound healing in DFI 1999 (n=613) the following results are shown (patients with MRSA in brackets): healing rate with conservative treatment 61.5% (20%), minor-amputation 30.5% (52%), major-amputation 4.5% (22%), death 3.5% (6%).

CONCLUSIONS

The rate of new infections were dramatically reduced by changing the hygienic measures. The rate of successful sanitation was unsatisfactoy. Patients with MRSA showed markedly poorer treatment results in respect to wound healing.

Methicillin-resistant Staphylococcus aureus. Nosocomial acquisition and carrier state in a wound care center

OBJECTIVE

To assess methicillin-resistant Staphylococcus aureus (MRSA) nosocomial acquisition and carrier state in a wound care center.

DESIGN AND SETTING

The results of an intervention to control MRSA were compared with those of historical controls at the wound care center of university-based Hôpital Broussais, Paris, France.

PATIENTS

Patients admitted for specific care of chronic ulcers and surgical wounds.

MAIN OUTCOME MEASURES

Incidence rates of MRSA carriers and acquisition in wounds.

RESULTS

Of 88 patients admitted during a 3-month preintervention period in 1993, 18 (21%) were MRSA carriers. Of 334 patients admitted in 1994 and 395 in 1996, 65 (19.5%) and 81 (20.5%) were MRSA carriers, respectively (P=.80). In 1993, 6 (9%) of 70 patients without MRSA acquired MRSA wound infections; the corresponding numbers were 6 (2.2%) of 269 in 1994 and 3 (0.9%) of 314 in 1996. Despite that the number of MRSA carriers remained stable at admission to the wound care center, the rate of MRSA infections in wounds per 100 noncarriers decreased significantly between the preintervention period and subsequent years: 1994 (P=.02) and 1996 (P=.002).

CONCLUSIONS

Although our results are limited by the use of historical controls, they showed that simple infection control measures, such as the use of soap and water and barrier precautions associated with staff education, seemed to significantly reduce MRSA infection rates in patients with chronic skin breaks.

[Tattooing and body piercing--experiences from public health infection surveillance by a public health office]

Tattooing and piercing have become increasingly popular in recent years. Both methods involve several medical risks, including transmission of infectious diseases. There are many reports on wound infections as well as transmission of hepatitis and human immunodeficiency viruses etc. According to these facts special hygiene regulations for tattooing and piercing have been published in Germany. Based on these regulations the public health department of the city of Frankfurt am Main, Germany, carried out special hygiene controls in such studios, one a year. Special tattoo or piercing exhibitions were also controlled. Results are reported here.

MATERIAL AND METHOD

Studios for tattoos or piercing were informed about hygiene rules and annually controlled from 1995-1999, using a special check list on cleanliness in the studios, disinfection and sterilisation procedures etc. For permission of tattoo and piercing exhibitions special hygiene orders were made mandatory.

RESULTS

During 1995-1997 the absolute number of complaints decreased from 20 to 9, in spite of the increasing number of tattoo studios in Frankfurt am Main (from 6 to 10). This was true also of the tattoo and piercing exhibitions. After 1 year without control visits however, an increase of complaints was to be seen in 1999.

DISCUSSION

According to our experience tattooists and piercers are interested in good hygiene practice. But our data showing the worsening hygiene data in one year without control visits also demonstrate the necessity of regular controls by the authorities. According to the reports on infectious complications of tattooing and piercing and according to the data reported here hygienic advice and control is an important task of Public Health services.

Salmonella senftenberg: a new pathogen in the burns ward

This is the first report of Salmonella senftenberg serovar outbreak in a burns unit. This unit admits about 2000 patients with major burn injuries annually. Routine sampling from wound swabs in December 1995 revealed S. senftenberg in a few samples following which a study was instituted from January to March 1996. Of 446 burn admissions during this period 80 patients were culture positive for S. senftenberg in wound swabs. The protocol for investigation included wound swabs on admission and then at biweekly interval, blood culture studies on clinically toxic patients, anti-microbial sensitivity studies, environmental sampling and hand swabs and stool cultures from about 50 staff members of the burns ward. No wound swab at the time of admission was positive for S. senftenberg. Environmental study and the study of staff members did not reveal any obvious source of the infection. S. senftenberg strains were sensitive to more than seven of the 11 anti-microbials tested at the beginning of the study but later 96.3% of the strains showed multidrug (more than three drugs) resistance. By April 1996 the isolates became negligible and later disappeared completely. The organism resurfaced again in March 1997 and the same study was instituted again on 413 admissions between March and May 1997. Fifty patients were culture positive for S. senftenberg. This time stool sample from one burn dresser tested positive for S. senftenberg. Interestingly, again at the beginning of the second outbreak the Salmonella strains were sensitive to 9 out of 11 anti-microbials tested, but later 96.11% strains became multidrug resistant. S. senftenberg strains showed maximum resistance to amoxycillin (97.5%) and minimum to chloramphenicol, tetracycline and cotrimoxazole (12%). It was noticed that Salmonella strains surfaced in wound swabs after 3-4 weeks of hospital stay. Forty-five out of 130 patients studied, in both the episodes, died due to septicemia. The majority of the patients who died had sustained > 60% TBSA burns. Blood cultures were done in 34/130 patients and eight yielded growth (2 S. senftenberg, 4 Klebsiella spp., and two Pseudomonas spp.)

An outbreak of extended-spectrum, beta-lactamase-producing Salmonella senftenberg in a burns ward

A strain of Salmonella senftenberg resistant to ceftazidime, gentamicin, chloramphenicol and ciprofloxacin was isolated from burn wounds of eight patients on a burns ward of a hospital in Delhi, India. The organism, which had probably been spread from patient to patient on staff hands, produced the extended-spectrum beta-lactamase SHV-5 and the aminoglycoside-modifying enzymes AAC(3)II + AAC(6'). The strain was not isolated from stool cultures of any of the patients or staff, apart from the index patient who had a history of diarrhoea and fever before admission. The outbreak ended in three weeks, after the implementation of strict handwashing. This is the first report of SHV-5 beta-lactamase in Salmonella spp. and also the first report of SHV-5 in India. The extended-spectrum beta-lactamases that have been reported in Salmonella spp. now include the Group 2 be enzymes SHV-2, SHV-5, TEM-3, TEM-25, TEM-27, CTX-M2, PER-1 and PER-2, and the Group 1 enzymes DHA-1 and CMY-2. The types of extended-spectrum beta-lactamases produced by salmonellas, their association with aminoglycoside resistance and their geographical distribution are now similar to those seen in klebsiella. Increasing antibiotic resistance in these organisms is reducing therapeutic options for the treatment of invasive disease.

Control of methicillin-resistant Staphylococcus aureus in a pediatric burn unit

BACKGROUND

Control of methicillin-resistant Staphylococcus aureus (MRSA) is particularly difficult in burn units, which are often cited as sources of hospital-wide MRSA outbreaks. We developed a successful MRSA control program and document here its apparent effectiveness in controlling MRSA transmission in a pediatric burn unit.

METHODS

An MRSA control program that included surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers was consistently applied in a pediatric burn unit through a 7-year period. Microbiology reports of MRSA isolates from patients and environmental surfaces and records of all patients from whom MRSA was isolated were reviewed.

RESULTS

During calendar years 1985 through 1991, a total of 991 acutely burned children were admitted to the Boston unit of the Shriners Burns Institute. Forty MRSA cases (4%) were identified. One patient both had MRSA at admission and met our criteria for nosocomial MRSA. Of the remaining 39 patients, 11 had MRSA at admission and 28 had nosocomial MRSA. There were 17 wound infections, two cases of pneumonia, and two bloodstream infections. No deaths were attributed to MRSA sepsis.

CONCLUSION

An MRSA control program including surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers is associated with a low rate of nosocomial MRSA in a pediatric burn unit.

Soft tissue facial injuries in sport (excluding the eye)

Facial injuries in sport have until recently received little publicity. Certainly, compared to other forms of injury, particularly orthopaedic, they seem neither to occur as frequently nor to have the same significance in relationship to complications, resulting in time off the sport, or long-term problems. Obtaining figures relating to the frequency of facial injuries in different sports is not easy because they are often trivial or considered so to be. Record-keeping by club staff can be erratic to say the least and many injuries do not reach hospitals. Increased interest in facial injuries is occurring as a result of a number of factors, including fears regarding transfer of blood-spread infections in contact sports and the increasing aggression occurring in some sports resulting in injuries to players, officials, and supporters during or even after the event. Possible reasons for this are discussed, as will be the implications.

Attempts to eradicate methicillin-resistant Staphylococcus aureus from a long-term-care facility with the use of mupirocin ointment

PURPOSE

To assess the impact of the use of mupirocin ointment on colonization, transmission, and infection with methicillin-resistant Staphylococcus aureus (MRSA) in a long-term-care facility.

PATIENTS AND METHODS

All 321 residents of a Veterans Affairs long-term-care facility from June 1990 through June 1991 were studied for MRSA colonization and infection. MRSA-colonized patients received mupirocin ointment to nares in the first 7 months and to nares and wounds in the second 5 months. The effect of mupirocin use on MRSA colonization and infection was monitored. All S. aureus strains isolated were tested for the development of resistance to mupirocin.

RESULTS

A total of 65 patients colonized with MRSA received mupirocin ointment. Mupirocin rapidly eliminated MRSA at the sites treated in most patients by the end of 1 week. Weekly maintenance mupirocin was not adequate to prevent recurrences--40% of patients had recurrence of MRSA. Overall, MRSA colonization in the facility, which was 22.7% +/- 1% prior to the use of mupirocin, did not change when mupirocin was used in nares only (22.2% +/- 2.1%), but did decrease to 11.5% +/- 1.8% when mupirocin was used in nares and wounds. Although colonization decreased, roommate-to-roommate transmission and MRSA infection rates, low to begin with, did not change when mupirocin was used. Mupirocin-resistant MRSA strains were isolated in 10.8% of patients.

CONCLUSIONS

Mupirocin ointment is effective at decreasing colonization with MRSA. However, constant surveillance was required to identify patients colonized at admission or experiencing recurrence of MRSA during maintenance treatment. Long-term use of mupirocin selected for mupirocin-resistant MRSA strains. Mupirocin should be saved for use in outbreak situations, and not used over the long term in facilities with endemic MRSA colonization.

[Pathogen spectrum and pathways of infection at an intensive care burn unit]

Coagulase-negative staphylococci have gained increasing importance in burns, whereas interest is no longer focussed on Pseudomonas bacteria. By means of microbiological analysis of swabs taken from patients, environment and staff, we trailed the routes of infection in an intensive-care unit for burns. Analysis of patients: In 27 out of 11 patients the same biotype of Staphylococcus epidermidis could be identified; 22 of these occurred in swabs from wounds. The phagotypification of Staphylococcus aureus showed the same phagotype in 28 out of 41 swabs taken from infected wounds of 10 patients. The pathogen mostly caused the destruction of already healed grafts in a later phase of the treatment. Further microbiological analysis showed a severe infestation of the patients by enterococci. Analysis of environment: Here, greatly increased counts of coagulase-negative staphylococci of the same lysotype as in the patients could be demonstrated. Analysis of staff: The naso-pharyngeal area is of minor importance in the spreading of germs, whereas that of protective clothing and especially the hands should be considered to be more crucial. Regular environmental tests enable rapid detection of hygienic errors so that appropriate countermeasures can be taken.

Vibrio vulnificus

V vulnificus is a halophilic or salt-requiring vibrio that has been isolated repeatedly from seawater and shellfish in coastal waters. This vibrio, first described by Hollis et al in 1976, can be differentiated from other similar vibrios by its ability to ferment lactose and by its lower tolerance for sodium chloride. V vulnificus, unlike most other vibrios, has seldom been incriminated as a cause of gastroenteritis but is a particularly virulent organism that causes severe wound infections in mostly healthy persons, or causes primary septicemia in persons with an underlying chronic disease, particularly chronic liver disease. Wound infections may range from relatively mild to severe and rapidly progressive cellulitis and myositis. Approximately 50% of patients with wound infections have some type of chronic underlying disease and the mortality rate is in the range of 15%. Wound infections are almost always associated with contact with seawater or the handling or cleaning of shellfish. Patients with primary septicemia have fever, chills, and prostration, and rapidly become hypotensive. Over 70% have distinctive bullous skin lesions that can strongly suggest the diagnosis in a patient with the appropriate history. The mortality rate is over 50%. There is a striking association between eating raw oysters and primary septicemia, with patients usually reporting having eaten raw oysters (or other shellfish) 24 to 48 hours before onset of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

[Modelling of the epidemic process of suppurative septic infections using a Pseudomonas aeruginosa bacteriophage]

The method for modeling the epidemic process of pyoseptic infections with the use of P. aeruginosa bacteriophage is proposed. The application of this method in urological and traumatological wards has made it possible to confirm the role of patients as the sources of infection and the part played by instruments and the hands of the medical personnel in its transfer.

Effects of environment on infection in burn patients

Burn patients in an early cohort (n = 173) treated in an intensive care ward without separate enclosures were compared with a later cohort (n = 213) treated in a renovated unit with separate bed enclosures. The number of patients developing infection was significantly reduced in the late group. Observed mortality was compared with mortality predicted on the basis of burn size and age alone. Reduction in observed compared with predicted mortality, inapparent in the early group, was seen in the late group and was restricted to the subgroup of patients with predicted mortality of 25% to 75%, in which the observed mortality of 28.3% was less than the predicted mortality of 48.7%. The incidence of infected patients was reduced from 58.1% in the early cohort to 30.4% in the late cohort. In comparison of the early cohort with the late cohort, the overall proportion of patients with bacteremia was reduced from 20.1% to 9.4%, while the incidences of both pneumonia and burn wound invasion remained unchanged. Providencia and Pseudomonas species, endemic in the early cohort, were eliminated in the late cohort. Reduction of infection by environmental manipulation in burn patients was possible and was associated with improved survival.

[Method of isolating conditionally-pathogenic Gram-negative microorganisms, agents of intrahospital infections, from air]

The possibility of detecting Pseudomonas aeruginosa and other Gram-negative bacteria in the air of the burn department at the Institute of Surgery was studied. The investigation of large volumes of air (0.5-1 m3) in the wards and the corridor with the use of a new bacteriological aerosol sampler, model IIAB-5, resulted in the detection of Pseudomonas aeruginosa. Besides, in a number of other rooms Klebsiella, Proteus, Citrobacter and Enterobacter were detected in the air. The possibility of the spread of Gram-negative opportunistic bacteria through the air in hospital conditions is discussed.

The prevention of wound infections in burn patients

To investigate the necessity of "protective isolation" and/or gastrointestinal tract decontamination in the prevention of infections in burn patients treated under ward conditions, a bacteriological inventory of burn sites, oropharynx and faeces was made 3 times a week. The origin of bacteria isolated from the lesions was determined by typing. In addition, the effect of local protection by topical application of silver-sulphadiazine or nitrofuralum was investigated. Of potentially pathogenic bacteria known to cause infections in burn, St. aureus was found to be almost exclusively exogenous in origin. Str. pyogenes, on the other hand, appeared either to be strongly inhibited by topical treatment or else to have colonized the wounds only from endogenous sources. Endogenous (gi-tract) Enterobacteriaceae biotype-positive samples were restricted to burn sites near the mouth and the anus. Enterobacteriaceae biotypes of exogenous origin appeared to colonize wounds of about one third of the patients. It is concluded that topical protection is insufficient in the prevention of bacterial colonization of the lesions. Therefore, protective isolation (St. aureus, etc.) and selective gastrointestinal decontamination are to be considered for infection prevention.

Isolation care of infection-prone burn patients

An experimental and clinical study of spread of colonisation between burn patients, and their susceptibility to infection, was performed. Burn patients' polymorphonuclear neutrophil granulocytes (PMN) functioned poorly, particularly during the second week after injury which coincided with maximum growth of bacteria in the burn wound. Patients with large burns often dispersed S. aureus and Ps. aeruginosa but also beta-hemolytic Streptococcus to the air of their rooms. Airborne transfer of these bacteria was practically eliminated by nursing in single isolation rooms with plenum ventilation. In such rooms, cross-contamination was carried mainly via clothes. Patients with small burns sometimes were important sources of such contamination although they dispersed little bacteria to the air. A thorough change of barrier dress after close contact nursing delayed the first exogenous S. aureus colonisation until after the time of greatest impairment in PMN functions. A further reduction in cross-contamination would be possible with barrier garments impermeable to fluids and bacteria on points of contact, as shown in experiments with plastic apron as protective dress. Measurements of penetration through fabrics of particles suspended in air, commercially used, did not correlate to the performance of garments made from the fabrics in experimental nursing and clinical use. Bacteria were shown to penetrate fabrics through rubbing, particularly when wet where the microcolonies present on the cloth were separated into smaller units. An instrument was designed which measured such penetration, and was used to select fabrics for barrier garments. Tightly fitting barrier garments increased the disperal of bacteria from clothes worn underneath them. The wearing of barrier garments should therefore be restricted to close contact nursing. An open-roofed plastic patient isolator was designed and built. It did not appreciably reduce cross-contamination and gave psychological and practical problems. It seemed not to be a realistic alternative to better protective garments in isolation rooms.

The contribution of a bacterially isolated environment to the prevention of infection in seriously burned patients

A new system of patient protection from bacterial crossinfection called the Bacteria Controlled Nursing Unit (BCNU) is described, based on strict environmental control of a 6 x 10 foot area surrounding the patient's bed rather than the entire patient room or isolation ward, plus the ability to deliver all medical care without entering the protective environment and maintaining all monitoring, life support, and i.v. equipment outside the controlled environment. The clinical effectiveness of this system in the treatment of burn patients has been studied and compared with the effectiveness of single room isolation on a burn isolation ward and conventional isolation techniques on an open burn ward. The studies show that the BCNU is significantly more effective in preventing bacterial cross-contamination than conventional precautions (3.8% vs. 13.1%, P < 0.001; and 8% vs. 22.8%, P < 0.001) over a two and four week period. The studies also indicate that there was a significant increase in the probability of infection occurring following cross-contamination than occurring after auto-contamination (65% vs. 39%, P < 0.005), emphasizing the importance of preventing cross-contamination in reducing the overall infection rate in seriously burned patients. Clinical evaluation of the unit proved it to be compatible with intensive nursing and medical care without increasing the nurse to patient ratio. The unit provided sufficient control of bacterial cross-infection to allow reduction in mortality and improvement in the effectiveness of burn care through routine prompt excision of burn eschar and immediate wound closure to be carried out in severe and massively burned patients without a limiting threat of bacterial burn wound sepsis.