SUMMARY. A retrospective study of infection in burn patients admitted to the Clinic for Burns and Reconstructive Surgery Kosice-Saca in the period 2003 to 2006 confirms the increased trend of Acinetobacter (Act) strains, as a multi-drug-resistant potential pathogen, Over 270 patients are admitted every year to our burn clinic with serious burn injuries, and 75 (on average) to the ICU Since 1992 the bacterial strain A. baumanni has been sporadically isolated from the wound swabs of the patients admitted to Intensive Care Units (ICU): in 1999 there was a rapid increase in the number of isolates of A. baumannii with increasing resistance to the usual antimicrobials, without clinical manifestation. In 2003, 11 % of all hospitalized patients were colonized with A. baumannii but in 2004 the figure for patients in ICU was 10%. In 2006, 3 patients developed sepsis 5 patients had uroinfection, 2 patients had pneumonia, and 7 patients had serious wound infections. Wound colonization was confirmed in 17 patients that year. A. baumannii resistance significantly increased after 2003, before the introduction of effective antibiotics against A. baumannii: Ampicilin/Sulbactam (from 16% to 55%) Gentamycin (72%-90%), and Meropenem (from 0% to 4 %) The first multi-drug-resistant Acinetobacter baumannii was recorded in 2006 in 8 patients (11 % ): two patients died of sepsis. Consequently, intensive surveillance of A. baumannii isolates was initiated. The objectives of this investigation were to define the epidemiology of the outbreak and to determine the risk factors for colonization or infection with A. baumannii.
Key words: Acinetobacter baumannii, gram-negative sepsis, Meropenem, resistance
Acinetobacter was described for the first time by Bcijerink as Micrococcus calco-aceticus (Beijerinck 1911), while a detailed study was presented later by Baumann et al. in 1968 and Bouvet and Grimont in 1986 (2, 7).
The Acinetobacter genus is one of a number of non-fermenting aerobic gram-negative structures (1). Acb can be isolated from soil, water and raw meat samples and are part of the physiological bacterial flora of the skin, especially in the areas of the perineum, inguina and axillas (2, 3). Due to their distinct adhesive ability to epithelial cells, the process of colonization or infection of the skin, wounds, mucous membranes and upper respiratory airways gives priority to Acinetobacters in comparison with other microbes (5).
The hospital environment becomes a secondary source of contamination; technical equipment of the ICU ventilation, moisturizers, water, bronchoscopes, mattresses and pillows, all present a secondary reservoir of Acinetobacter strains (10, 11).
The ability of Aeb to survive in both very dry and wet conditionstheir affinity for plastic and metal materials-and their nonabrasive growth lead to failure in hygiene prophylaxis (12). In 2006 we recorded the first multi-drug-resistant Acinetobatter baumannii in A patients. The emergence of resistant strains has become a major problem in ICUs worldwide (I).
In 2006 we studied 270 admitted patients in our burn clinic, aged between 3 months and 91 years (mean 29.4±8,7); 71% were males. The actiology of the burn trauma was scalds (58.64%), flame (24.5%), electric burns (5.6%) and chemical agents (4.5%). Special attention was paid to all patients from ICU (34) with a record of invasive procedures, surgery and ATB treatment. The medical records of each patient were reviewed for age, sex, diagnosis, the date of the injury, admission to the ICU, length of stay in ICU. biological material and day of the first A. baumannii isolation, broad spectrum antibiotics used, topical antimicrobial treatment, presence of diagnostic and therapeutic and surgical interventions.
Bacterial culture swabs from burn wounds were taken on admission and every 48 hours a week depending on clinical status. Blood cultures were examined with use of the Bactec system (Becton Dickinson) taken with pending clinical status. Phenotype identification and isolation of A. baumannii was performed with the base standard microbiological methods. Biochemical identification was provided by BBL Crystal by Enteric/Neferm test (Becton Dickinson), and for sensitivity tests to 17 antimicrobial agents microdilution tests BclMiditech "ere used according to the norms established by the NCCLS (National Committee for Clinical Laboratory Standards).
During the period 2003-2006, 1087 patients were hospitalized at the Clinic for Burns in Kosicc. 4152 bacterial strains were isolated from biological material, mostly bacterial swabs, blood cultures, urine. sputum etc. The 2991 most frequently isolated bacterial strains, with serious clinical impact, were collected for statistical analysis and for more detailed study (Table I).
<% immagine "Fig. 1","gr0000034.jpg"," The most frequent isolated in Burn Department and ICU (in %)",230 %> <% immagine "Table 1","gr0000035.jpg","Incidence of bacterial strains in burn department and ICU in 2006 ",230 %>StaphYlococcus aureus was isolated in 840 cases (20%) - the highest incidence. Of the gram-negative isolated bacterial strains in this period, Acinetobacter baumannii was found with 513 isolates (12%) and Pseudomonas aeruginosa with 512 isolates (12%). E. coli was the most frequently isolated one, with 551 positive cultures (12.8%) (Fig. 1). Other, small numbers of isolates (Proteus vulgaris, Morganella morganii, Enterobacter aerogenes, Enterobacter cloace, Candida albicans) were not included in the study.
In 2003, 134 A. baumannii species were isolated with resistance to Ampicilin/Sulbactam (I6 %r,) and Meropenem (0%) at that time; in 2006, 132 isolates significantly demonstrated increased resistance to Ampicilin/Sulbactam (up to 55%) and Meropenern (4%). The highest resistance was to Gentamycin, which increased to 90%0 (Table 2).
<% immagine "Table 2","gr0000036.jpg","Distribution of A. baumannii resistance in 2003-2006 ",230 %>A group of 34 patients admitted to the ICU in 2006 with positive evidence of A. baumannii strains from biological material were selected for detailed study (Table 3). The group of 34 patients comprised 22 adults with a mean age of 50 years (range 2079) and 12 children with a mean age 5 years (range 1-15)! 24 patients (7190) were males and 10 (29%) were females. All of the patients were admitted to the ICU with TBSA 27% (range 3-78%). Ten patients (29%r) were admitted to the ICU on the day of the injury and 24 patients (7 l %) were admitted to the ICU from other hospitals 48 hours post bum injury. Four patients (12%) had isolated A. baumannii from the wound swabs on the day of the admission to the ICU. After the next 48 hours, 3 patients (9%) had their first positive isolation. On average, 27 patients (79%) had positive isolation of A. baumannii from wound swabs on the sixth day after admission to the ICU. Table 3 shows that all patients with a positive isolation of A. baumannii strains fulfilled the criteria of the development of Acb colonization or infection confirmed by microbiological and laboratory tests. Sepsis in 3 patients, uroinfection in 5 patients, pneumonia in 2 patients and wound infection in 7 patients were also confirmed. Two patients (5.8%) died after multiorgan failure because of sepsis on 23,11 and 29th post burn day. According to our observation. 24 (79%) A. baumannii isolates were in mixed cultures with other bacterial strains, such as Staphylococcus aureus, Pseudomonas aeruginosa, E. coli. etc.
<% immagine "Table 3","gr0000037.jpg","ICU patients with positive isolations if Acinetobacter complex strains from biologial material in 2006 ",230 %>Microbiological and clinical tests confirmed A. baumannii eradication in 15 patients (44%) which was performed by aggressive antimicrobial treatment.
Positive A. baunuannii isolations in 19 (56%r.) patients persisted until all the wounds healed. Most successful eradication of wounds was performed by surgery and Sulfamylon solution. Sepsis and septic complications were treated by high doses of Meropenem, Imipenem/Cilastatin or a combination of Amikacin /Meropenem.
In 2006 Acinetobacter became the second bacterial strain most often isolated from the biological material of burn patients admitted to ICU (Fig. 2).
<% immagine "Fig. 2","gr0000038.jpg","Incidence of bacterial strains in ICU in 2006 ",230 %>Tables 4-7 show the distribution of tested antimicrobials on isolated A. baumannii from Burn Department and ICU from 2003 to 2006.
<% immagine "Table 4","gr0000039.jpg","Distribution of Acinetobacter baumannii resistance (2003) ",230 %>n* No. of isolated tested
s* Percent susceptible
M* Percent moderately susceptile
R* Percent resistant
n* No. of isolated tested
s* Percent susceptible
M* Percent moderately susceptile
R* Percent resistant
n* No. of isolated tested
s* Percent susceptible
M* Percent moderately susceptile
R* Percent resistant
n* No. of isolated tested
s* Percent susceptible
M* Percent moderately susceptile
R* Percent resistant
Table 8 shows the resistance of tested antimicrobials on isolated A. baumannii from ICU in 2006. There were 6 (1190) multi-drugresistant A. baumannii strains in ICU and one in burn department.
<% immagine "Table 8","gr0000043.jpg","Distribution of Acinetobacter sp. resistance in ICU (2006) ",230 %>n* No. of isolated tested
s* Percent susceptible
M* Percent moderately susceptile
R* Percent resistant
Fleming, Chain and Florey discovered penicillin and were awarded the Nobel Prize for Medicine in 1945. Gerhard Domagk was awarded the Nobel Prize in 1939 for his discovery of prontosil. the first sulfonamid (14). Their discovery and development revolutionized modern medicine and paved the way for the development of many more natural antibiotics. Antibiotics and Silversulfadiazinhave dramatically changed burn treatment. Shortly after the introduction of potent and broad-spectrum antibiotics, the emergence of resistant strains became a major problem in ICUs (7). Despite advances in surgical care and new antimicrobial agents. infection and sepsis are responsible for over 5W/° mortality in burn patients worldwide (8). The organisms that predominate as causative agents of burn wound infection in any burn treatment unit change over time. Initially prevalent grampositive infection is overgrown with gram-negative opportunists, mostly Pseudoznanas aeruginosa and Ac inetabacter baumannii (6, 9). The ability of Acinetobncter to survive in both very dry and wet conditions, their affinity for plastic and metal materials, and their unabrasive growth lead to failure in hvgiene prophylaxis (l2).
The increase in positive isolation of the Acb strains from the biological materials of burn patients, which was observed over recent years, and the very rapid development of resistance to antimicrohial medication, led us to the analysis of the problem. The ubiquitous microbe, with no clear clinical impact, has changed into a dangerous and very competitive nosocomiat pathogen (28). This study also confirmed and sufficient data demonstrated serious danger for the burn patient from this pathogen.
In 2006 all patients included in this study with positive isolation of A. baumannii strains fulfilled the criteria of the development of A. baumannii colonization or infection by microbiological and laboratory testing. Two patients died after multi-organ failure because of Aeinctobacter sepsis.
Identifying infections in the ICU can be challenging. Bedside imaging and laboratory, markers such as neutrophil count, erythrocyte sedimentation rate and C reactive protein (CRP) are nonspecific and cannot reliably confirm bacterial infection. Procalcitonin (PTC) may be a useful prognostic marker to indicate bacterial infection. A positive blood test and quantitative bacterial culture of resistant A. baumannii represent a high risk for patient, and because of the limited number of effective ATB this is a challenge for everyone who cares for burn patients (25). Carbapenems are limited; only Colimycin, Riphampicin and the new ATB like Tigecychn may help to solve septic complications.
According to our observation 24 (79%) of A. baumannii isolates were present in mixed cultures with other bacterial strains such as Staphylococcus aureus, Pseudomonas aeruginosa, E. coli, Proteus sp.
The eradication of A. baunzannii strains was successful in 15 (44%) patients, which was confirmed clinically and microbiologically. In 19 patients (56%), positive A. haumannii isolations persisted during the treatment.
There is a high risk to receive Acinetobacter infection during the hospital stay. On average 79% of patients had their first positive isolation of A. baumannii strains on the sixth day of hospitalisation in the ICU. Only 21% patients had their positive isolation within 48 hours of admission. All patients with a positive isolation of A, baunzannii fulfilled all the criteria of the development of A. bnumannii colonization or infection (see Table 3). Clinical. microbioloa ical and other laboratory examination confirmed that 17 (50`/°) patients developed A. baumannli infection. There was sepsis in 3 patients, pneumonia in 2 patients. uroinfection in 5 patients and wound infection in 12 patients. Wounds and mucosa colonization was confirmed in 507° of patients.
Microbiologically and clinically confirmed eradication of A. bauncnnnii strains from wounds was successful in 15 patients. In 19 patients (56%), positive A. baumannii isolations persisted until all the wounds healed.
In general, fast, second and third generation cephalosporins, macrolides. and penicillins have little or no anti-Ac inetobacter activity, and their use may predispose to Acinetobacter colonization (6).
As summarized by Go and Cunha (1999), medication to which Aci«etobacter is usually sensitive include Meropenem, Colistin, Amikacin. Minocyclinc and Tigccycline (6). Colonization of one patient may result in infection in another patient. For these reasons, every attempt should be made to isolate patients who are colonized with Acinetobacter in order to prevent other patients from becoming colonized (26). According to our observation 24 (79%) of A. baumannii isolates were present in mixed cultures with other bacterial strains such as Staphylococcus aureus, Pseudomonas aeruginosa, Eraerobacter spp.In our opinion there are several possibilities to minimize the problem of A. baumannii infections or colonizations of the burned patient.
Address for correspondence: