Efficacy testing of topical delivered moxifloxacin against MRSA in a porcine wound infection model

Burns 3 5 S ( 2 0 0 9 ) S1–S47

FRI011 Zygomycetes in BICU 1,∗ , H. Øíhová 1 , I. Kocmanová 2 , M. Hanzliánová 2 , I. ˇ B. Lipovy´ 1 , Z. Zaloudíková Suchánek 1 , Y. Kaloudová 1 , P. Brychta 1 1 Department of Burns and Reconstructive Surgery, Czech Republic 2 Department of Microbiology, Faculty Hospital Brno, Brno, Czech Republic

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effects were observed. Moxifloxacin has promise to be a potential new therapeutic option for the treatment of MRSA wound infection. doi:10.1016/j.burns.2009.06.155

FRI021 A multiple drug resistant Acinetobacter baumannii outbreak in a burn center: Trying

Rationale: Mycotic infections are not as common as bacterial, but are more difficult to diagnose and to treat. The Zygomycetes represent only 2% of all the mycotic infections, are relatively uncommon in the clinical laboratory, and less commonly, cause a clinical disease called zygomycosis. It is a rare invasive fungal

to stop the unstoppable? J.S. Champagne ∗ , K.N. Foster, D.M. Caruso, M.D. Peck, M.R. Matthews, R.D. Neibaur, G.J. Haught-Neese Burn, Arizona Burn Center, Phoenix, AZ, United States

infection seen most often in immunosuppressed patients. In a severe burn patient

Rationale: Acinetobacter baumannii is an aerobic nonfermentative gram negative coc-

at BICU it is often necessary to use broad-spectrum antibiotic treatment. Then the

cobacillus that is known to cause infections in burn patients. Endemic strains of

zygomycetes infection can occur in immunocompromised patient as an oppor-

multiple drug resistant (MDR) A. baumannii are not uncommon in burn intensive

tunist. Even if the zygomycetes infections in BICU are very rare, once it occurs,

care units and much has been published on outbreaks related to this organism.

is very resistant to the therapy. It can cause severe sepsis and the death of the

Nonetheless, outbreaks continue to occur.

patient. The diagnosis of zygomycosis is rarely suspected and ante mortem diag-

Methods: Once determined the burn center was experiencing an A. baumannii

nosis is made in only 23–50% of cases. Zygomycosis has a high mortality/lethality

outbreak, assistance was requested from public health agencies and laborato-

of 80% (comparing to other mycotic infections, which is 50–60% for candidas and

ries. An epidemiological investigation was launched and included retrospective

aspergillus). Today the biggest problem is to diagnose the zygomycetes infec-

data analyses and surveillance cultures using pulsed field gel electrophoresis for

tion due to the lack of the “golden standard” of the early diagnostics. A method

identification. A review of infection control and environmental policies was also

that can help us to haste the diagnostics and to optimalize an early therapy, is

conducted.

PCR.

Results: Over 2 years, 52 suspect cases of MDR and 57 non-MDR acinetobacter

Methods: We are presenting two case reports of patients that have been hospitalized

were identified. In the current cohort, three strains were identified as (A), (B)

in our BICU in the period from June till December 2008 with severe burn trauma.

and (D). Fifteen patients were culture + for strain (A), 4 patients were culture +

Results: BICU one patient survived and one died. We could confirm the difficulty of

for strain (B) and 1 patient was + for strain (D). One additional result was pend-

the diagnostics and the therapy of the zygomycetes infection. In our opinion, this

ing. Strain (A) was resistant to all but one class of drugs excluding colistin and

failure was due partly to a delay in the initial diagnosis and subsequent treatment.

tigecycline. Culture sites included catheter/blood, respiratory, wound/tissue, and

We have a low experience in diagnosing and managing zygomycetes infection,

urine. Contributory factors for infection were a TBSA of 35% or greater, intu-

as this case of fungal infection is extremely rare. A high index of suspicion,

bation, inadequate hand washing and room/equipment disinfection, inadequate

prompt histopathological confirmation or PCR, repeated surgical debridements and

or improper use of PPE. Interventions included increased surveillance, education

amphotericin-B are the cornerstones in the management of this disease.

and enhanced infection control and environmental services activities with great

Conclusion: The golden standard of the early diagnostics of the zygomycetes disease

success.

is still missing. Aggressive treatment needs to be instituted immediately without

Conclusion: Despite the wealth of information on MDR infections in burn patients,

waiting for culture results.

outbreaks continue to occur. Most interventions are focused on stopping the out-

doi:10.1016/j.burns.2009.06.154

break rather than preventing it. Few research studies have been conducted with an infection control focus as stated in the Centers for Disease Control and Preven-

FRI016 Efficacy testing of topical delivered moxifloxacin against MRSA in a porcine wound infection model C. Fisahn 1,∗ , F. Jacobsen 1 , I. Thiele 1 , S. Al-Benna 1 , B. Fugmann 2 , T. Hirsch 1 , H. Steinau 1 , L. Steinstraesser 1 1 Plastic Surgery, Burn Center, BG University Hospital Bergmannsheil, Bochum, Germany 2 Drug Discovery, Bayer Innovation, Duesseldorf, Germany

tion’s Infection Control Guidelines. Infection control research should be one of the burn community’s’ primary foci considering Medicare’s recent ruling questioning reimbursement for many healthcare acquired infections. doi:10.1016/j.burns.2009.06.156

FRI022 In vitro bacterial barrier properties of silver containing carboxymethylcellulose

Rationale: MRSA is a common cause of infections in wounds and associated with high morbidity. The emergence of bacterial resistance to multiple antibiotics has led to an increased urgency to develop new therapeutic options for wound infections. The aim of this study was to assess the antimicrobial activity of moxifloxacin

wound dressings S.M. Adams 1 , D. Pritchard 2 , J. Rogers 1,∗ 1 Hydrofiber Research and Development 2 Materials Testing, ConvaTec Wound Therapeutics GDC, Deeside, United Kingdom

in a preclinical large animal model of MRSA wound infection.

Rationale: To determine the effectiveness of silver containing carboxymethylcellu-

Methods: Six full thickness BO-wound chambers were implanted on each flank of

lose (Hydrofiber, ¥ Technology) wound dressings, in an in vitro model, which may

2 female Goettingen minipigs under general anaesthesia. 7 days after implan-

help prevent nosocomial infection of burn wounds.

tation wounds were inoculated with 1 × 108 colony forming units (cfu) of MRSA. After wound infection had been established and quantified (3 days after inocu-

Methods: 5 cm × 5 cm dressing samples were cut asceptically and placed on the surface of a TSA plate. A microbial challenge of 103 cfu/ml of Staphylococcus

lation), wounds were randomised and topically treated with either placebo–gel

aureus was pipetted onto the centre of each dressing sample and incubated

(carrier–control n = 7), 0.1% linezolid (n = 3), 0.1% mupirocin (n = 3), 2% mupirocin

at room temperature for 4 h. The dressing samples were then removed and

(commercial ointment; n = 4) or 0.1% moxifloxacin (n = 7). Topical treatment and

the plates incubated at 37¢XC for 48 h. Plates were examined for growth at 24

wound fluid collection was carried out every other day for 2 weeks for quantitative

and 48 h.

bacterial analysis to monitor wound infection. Animals were photographed every

Results: The control sample (gauze) showed growth at 24 and 48 h. The two silver

day to document macroscopic signs of infection. The animals were sacrificed 21

containing carboxymethylcellulose dressings exhibited no growth at either time

days post-inoculation and tissue biopsies were taken for histological analysis and

point.

quantitative bacterial counts.

Conclusion: Acquired infections are usually attributed to direct contact between

Results: Pre-treatment all wounds showed a high and stable bacterial infection

an infected or colonised person and the patient. The challenge organism, Staphy-

(>105 cfu/ml wound fluid). Antibiotic therapy with linezolid, mupirocin and moxi-

lococcus aureus, is a common pathogen found in wound infections. The bacterial

floxacin significantly reduced bacterial counts in wound fluid and tissue in contrast

concentration was chosen as being representative of the levels found on normal

to the carrier control. Moxifloxacin showed a strong antimicrobial activity (with up

skin. The gauze dressing provided no barrier to the transition of the challenge

to 103 reduction in bacterial counts) compared to carrier control (fluid p = 0.012,

organism to the agar plate whereas both silver containing carboxymethylcellulose

tissue p = 0.013). Linezolid and mupirocin showed comparable results.

dressings were able to protect the surface of the agar from the challenge organism.

Conclusion: All antibiotics showed high efficacy towards MRSA infection in this

The carboxymethylcellulose dressings may help prevent the spread of nosocomial

porcine full-thickness wound infection model. The activity of moxifloxacin is com-

infection in the clinical situation.

parable to that of clinically used antibiotics (linezolid, mupirocin) and no side

doi:10.1016/j.burns.2009.06.157