Emergence of community-acquired methicillin-resistant Staphylococcus aureus soft tissue infections

Purpose

Our objective is to describe the changing incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and its treatment within East Tennessee.

Methods

A retrospective chart review of 245 patients treated with incision and drainage of soft tissue infections from March 2000 to September 2005 was completed. Consent was obtained from our local institutional review board. Forty patients were excluded because no cultures were recorded or because they failed the criteria for the diagnosis of CA-MRSA. We examined our data using χ² analysis. P value of less than .05 was considered statistically significant.

Results

The most common organism cultured was CA-MRSA (33%; 67 of 205). Non-CA-MRSA accounted for 4% (9 of 205). The age of patients ranged from 1 month to 21 years, with a mean age of 6.5 years. Stratified by year, the incidence of positive cultures for CA-MRSA has increased 159% since 2004 and 868% since 2003. In addition, the average age of patients has decreased from 8.3 years in 2000 to 6.1 years in 2005.

Conclusions

Community-acquired MRSA has emerged as the dominant source of soft tissue infection requiring incision and drainage regardless of site in East Tennessee. This has caused a change in the choice of empiric antibiotic treatment of soft tissue abscesses in our region. These infections now account for the third most common reportable disease to the Department of Health in East Tennessee.     

Risk factors for acquisition of Methicillin-resistant Staphylococcus aureus among patients from a burn unit in Brazil

Methicillin-resistant Staphylococcus aureus (MRSA) is an important agent of colonization and infection in burn units. In order to identify risk factors for MRSA acquisition in a Brazilian burn unit, we performed two retrospective studies. In the first (“cohort” study), 175 patients who were not colonized with MRSA on admission were followed to assess risk factors for MRSA acquisition. In the second (“case–case–control” study), 143 individuals from the previous study who were negative for both MRSA and Methicillin-susceptible S. aureus (MSSA) on admission were followed. Case–control studies were performed to investigate risk factors for MRSA and MSSA acquisition. MRSA and MSSA were recovered from 75 and 23 patients, respectively. In the “cohort” study, only the number of wound excisions (Odds Ratio [OR] = 1.55, 95% Confidence Interval [CI] = 1.21–1.98, P = 0.001) was associated with MRSA acquisition. In the “case–case–control” study, burns involving head (OR = 3.43, 95%CI = 1.50–7.81, P = 0.003) and the number of wound excisions (OR = 1.83, 95%CI = 1.27–2.63, P = 0.001) were significant risk factors for MRSA. Burns involving perineum were negatively associated with MSSA acquisition (OR = 0.16, 95%CI = 0.03–0.75, P = 0.02). In conclusion, the acquisition of MRSA was related to the site of the burn and to the surgical manipulation of tissues, but not to the use of antimicrobials.     

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in a burn unit from Brazil

Methicillin-resistant Staphylococcus aureus (MRSA) poses a threat for patients in burn units. Studies that mix epidemiological designs with molecular typing may contribute to the development of strategies for MRSA control. We conducted a study including: molecular characterization of Staphylococcal Chromosome Cassette mecA (SCCmec), strain typing with pulsed field gel electrophoresis (PFGE) and detection of virulence genes, altogether with a case–case–control study that assessed risk factors for MRSA and for methicillin-susceptible S. aureus (MSSA), using S. aureus negative patients as controls. Strains were collected from clinical and surveillance cultures from October 2006 through March 2009. MRSA was isolated from 96 patients. Most isolates (94.8%) harbored SCCmec type III. SCCmec type IV was identified in isolates from four patients. In only one case it could be epidemiologically characterized as “community-associated”. PFGE typing identified 36 coexisting MRSA clones. When compared to MSSA (38 isolates), MRSA isolates were more likely to harbor two virulence genes: tst and lukPV. Previous stay in other hospital and admission to Intensive Care Unit were independent risk factors for both MRSA and MSSA, while the number of burn wound excisions was significantly related with the former (OR = 6.80, 95%CI = 3.54–13.07). In conclusion, our study found polyclonal endemicity of MRSA in a burn unit, possibly related to importing of strains from other hospitals. Also, it pointed out to a role of surgical procedures in the dissemination of MRSA strains.     

Characterisation of SCCmec elements in methicillin-resistant Staphylococcus aureus isolated from burn patients

Staphylococcus aureus is an important pathogen, especially in burn units all around the world. Because of the emergence of the β-lactam antibiotic-resistant strains since 1961, concern about the prevalence of methicillin-resistant S. aureus (MRSA) has increased in these units. Resistance to methicillin is mediated by penicillin-binding proteins (PBPs) that have enough affinity for binding to the β-lactam ring, but another kind of protein (PBP2α), which is encoded by the mecA gene, has a lower affinity for binding to these antibiotics. The mecA gene is transferred by SCCmec (staphylococcal cassette chromosome mec) as a mobile genetic element, exclusively found in the Staphylococcus genus. Identification of the frequency of the mecA gene, different SCCmec types and also its incidence may have benefit in surveillance prevention and control of MRSA strains in burn units. In this study, 40 S. aureus isolates were collected from patients hospitalised in Motahari burn center of Tehran, during 2012–2013. Conventional microbiological methods were applied and the confirmed isolates were stored at −20 °C for molecular polymerase chain reaction (PCR) tests. The antibiotic resistance pattern was performed by disc diffusion method and finally the different SCCmec types were determined by specific primers. During this research, 40 isolates of S. aureus were collected from burn patients, of which (37.5%) of the specimens belonged to female patients and 62.5% to male patients. The aetiology of the burn was classified as follows: open flame (35%), liquid (32.5%), chemical (5%) and other (27.5%). By a disc diffusion method, no resistance pattern was observed to vancomycin and fosfomycin. Based on a multiplex PCR assay, the five different SCCmec types were detected as: 47.5% type III, 25% type IV, 10% type V, 10% type II and 7.5% type I.     

An outbreak of a multiresistant methicillin-susceptible Staphylococcus aureus (MR-MSSA) strain in a burn centre: the importance of routine molecular typing

Here we report an outbreak among 17 patients caused by a single strain of a Multiresistant Methicillin-Susceptible Staphylococcus aureus (MR-MSSA) in a burn centre. The MR-MSSA strains were resistant to penicillin, ciprofloxacin, erythromycin, clindamycin and co-trimoxazole. Further analysis showed an increased prevalence of MR-MSSA carriership in S. aureus colonized patients admitted to the burn centre, from 0% in 2005 (0/118), 3.3% in 2006 (4/121), 6.1% in 2007 (6/99), to 7.8% in 2008 (7/90). Molecular typing with Amplified Fragment Length Polymorphism showed that all MR-MSSA isolates derived from burn centre patients had a unique genotype, and was different compared to isolates derived from other hospital patients. All healthcare workers (HCWs) who worked in the burn centre during the outbreak were screened for nasal carriage with MR-MSSA. One HCW tested positive for a genotype of MR-MSSA that was indistinguishable from the genotype found in samples of the burned patients. No new cases of MR-MSSA colonization or infection were identified after the colonized HCW stopped working at the burn centre. The routine practice of molecular typing of collected S. aureus strains from both patients and HCWs will help to detect nosocomial spread in a burn centre, and opens the possibility of a rapid, almost pre-emptive response.     

Prevention of Staphylococcus aureus burn wound colonization by nasal mupirocin

BACKGROUND: There are two important routes for the transmission of Staphylococcus aureus to the burn wound. In the endogenous route, patients naturally carrying S. aureus colonize their own wounds, whereas in the exogenous route burn wounds are cross-infected from other sources. In this study we evaluated the effect of blocking the endogenous route on S. aureus burn wound colonization by mupirocin application in the nose of patients at the time of admission. METHODS: From September 2000 to January 2002 all patients with burns admitted to a single dedicated Burn Centre received nasal mupirocin upon admission. This period was compared to two control periods (C1: July 1999 to July 2000 and C2: January 2002 to January 2003) for S. aureus burn wound colonization. The colonization risk was analysed, adjusting for confounding, with Cox proportional hazard regression. RESULTS: A total of 98 patients did not have S. aureus burn wound colonization at the time of admission and were, thus, considered at risk for S. aureus acquisition during their stay. As compared to C1, the relative risk of acquiring S. aureus in their wound was 0.48 (95% CI: 0.24-0.97) in the mupirocin period and 0.55 (95% CI: 0.28-1.1) during the C2 period. S. aureus nasal/pharyngeal colonization was a significant independent risk factor for wound colonization (RR: 2.3; 95% CI: 1.2-4.2). CONCLUSION: Nasal mupirocin may contribute to risk reduction of S. aureus wound colonization in patients with burns.     

A prospective study of methicillin-resistant Staphylococcus aureus colonization in children scheduled for elective surgery

Background

Staphylococcus aureus is a major cause of surgical wound infections. To obtain contemporary data on S aureus, we performed a prospective study of colonization and infection in children scheduled for elective surgical procedures.

Methods

A nasal swab and clinical information were obtained at the presurgical outpatient visit. At operation, nasal and perianal swabs were obtained. S aureus were isolated and characterized.

Results

We enrolled 499 patients from June 2005 to April 2007. Wound classes were 1 (73%), 2 (22%), 3 (5%), and 4 (0.2%). Prophylactic antibiotics were administered for 153 (31%). Postoperative length of stay ranged from 0 (77%) to 6 days, with 19 (4%) staying 4 days or more. Screening cultures grew S aureus for 186 procedures (36.6%); of these, 141 were methicillin-resistant S aureus (MRSA) (76% of all staphylococcal cultures or 28% of all procedures). Most MRSA had Staphylococcal Chromosomal Cassette mec type II and resistance to clindamycin—typical for hospital-associated strains. There were 10 (2%) surgical site infections, including 4 methicillin-sensitive S aureus, 1 MRSA, 2 with no growth, and 2 with no cultures.

Conclusion

Methicillin-resistant S aureus colonization was common in asymptomatic children. Most strains appeared to be health care-associated and resistant to clindamycin. Wound infection rate remained low despite the high prevalence of staphylococcal colonization.     

2002-2006年灼伤病房金黄色葡萄球菌耐药情况分析

目的：分析上海瑞金医院灼伤科2002-2006年住院患者金黄色葡萄球菌耐药率的变化和抗菌药物的使用情况,为合理应用抗菌药物提供依据。方法：调查上海瑞金医院2002-2006年灼伤病房细菌的流行病学,抗菌药物的使用量以及金黄色葡萄球菌的耐药变化。结果：①病房分离的主要细菌是金黄色葡萄球菌（29.48%-41.06%）和铜绿假单胞菌（15.59%-23.39%）。②头孢拉定（80.45-286.34DDDs/100住院人天）、头孢哌酮（11.64-238.97 DDDs/100住院人天）等β-内酰胺类抗生素是病房使用最多的抗菌药物,万古霉素（43.19-82.18 DDDs/100住院人天）、阿米卡星（38.99-125.52 DDDs/100住院人天）、环丙沙星（1.96-163.41 DDDs/100住院人天）的使用量也比较大。③金黄色葡萄球菌对几种常用抗菌药物的耐药情况研究显示,青霉素（98.0%-100.0%）、阿米卡星（72.4%-86.1%）、头孢唑啉（68.5%-85.1%）、环丙沙星（51.5%-81.2%）、苯唑西林（72.7%-85.1%）耐药率都比较高,而万古霉素尚未发现耐药菌株。青霉素和阿米卡星的耐药情况较严重,使用量也有相应减少。环丙沙星的耐药情况有所缓解,使用量则相应增加。结论：病房金黄色葡萄球菌的耐药情况比较严重,临床必须严格掌握抗菌药物的使用指证,根据药敏结果选择合适的抗菌药物,通过联合用药、选择不常用的敏感抗菌药物、减少耐药严重的抗菌药物的使用等手段来缓解细菌耐药情况。     

A high prevalence of mupirocin and macrolide resistance determinant among Staphylococcus aureus strains isolated from burnt patients

Infections due to Staphylococcus aureus have become increasingly common among burn patients. The antibiotic resistance profile of S. aureus isolates and inducible resistance against clindamycin were investigated in this study. The presence of mecA gene, mupA gene and macrolide resistance genes were detected using PCR and multiplex-PCR. The resistance rate to methicillin, erythromycin and mupirocin were 58.5%, 58% and 40%, respectively. The prevalence of constitutive and inducible resistance among macrolide resistant isolates was 75% and 25%, respectively. Ninety five percent of the isolates were positive for one or more erm genes. The most common genes were ermA (75%), ermC (72%) and ermB (69%), respectively. The ermA gene predominated in the strains with the inducible phenotype, while ermC was more common in the isolates with the constitutive phenotype. The msrA gene was only found in one MRSA isolate with the constitutive phenotype. A total of 27 isolates (25%) carried the mupA gene. All the mupirocin resistant isolates and almost all the erythromycin resistant isolates were also resistant against methicillin which may indicate an outbreak of MRSA isolates with high-level mupirocin and erythromycin resistance in the burn unit assessed.     

A selected screening programme was less effective in the detection of methicillin-resistant Staphylococcus aureus colonisation in an orthopaedic unit

Purpose

Our unit has used a selective screening policy for methicillin-resistant Staphylococcus aureus (MRSA) colonisation using standard chromogenic growth media, based upon risk stratification. The aim of this study was to examine the effectiveness of this selective screening policy.

Methods

A cohort of 429 patients was assessed for their risk status for MRSA colonisation using both rapid polymerase chain reaction (PCR) swabs and traditional culture and sensitivity analysis. The sensitivity, specificity, positive predictive values and negative predictive values of the traditional selective approach were calculated compared to universal rapid screening.

Results

One hundred eighteen patients were considered high risk and would traditionally be further screened with standard culture of swabs. The prevalence of MRSA was 15/429 (3.5 %). The sensitivity of selective screening was 53 % identifying eight of 15 cases. The false-negative rate was therefore 47 % and seven would have been missed. PCR results were available within four to six hours, whereas culture results were only available at 24 hours for the media showing no growth and not until 72 hours for positive MRSA cases.

Conclusions

We now advocate universal screening prior to, or on admission, using this rapid PCR test, as we consider this identifies MRSA colonisation more effectively and facilitates “ring-fencing” of orthopaedic beds.     

Twenty-five year epidemiology of invasive methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered at a burn center

Over the past two decades, an epidemiologic emergence of methicillin-resistant Staphylococcus aureus (MRSA) infections has occurred from that of primarily hospital-associated to community-associated. This emergence change has involved MRSA of different pulsed-field types (PFT), with different virulence genes and antimicrobial resistance patterns. In this study we, evaluate the changes in PFT and antimicrobial resistance epidemiology of invasive MRSA isolates over 25 years at a single burn unit. Isolates were tested by pulsed-field gel electrophoresis (PFGE), broth microdilution antimicrobial susceptibility testing, and PCR for the virulence factors Panton–Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME), and the resistance marker staphylococcal chromosomal cassette mec (SCCmec). Forty isolates were screened, revealing stable vancomycin susceptibility MIC without changes over time but decreasing susceptibility to clindamycin and ciprofloxacin. The majority of PFGE types were MRSA USA800 carrying the SCCmec I element and USA100 carrying the SCCmec II element. No strains typically associated with community-associated MRSA, USA300 or USA400, were found. USA800 isolates were predominately found in the 1980s, USA600 isolates were primarily found in the 1990s, and USA100 isolates were found in the 2000s. The PVL gene was present in only one isolate, the sole USA500 isolate, from 1987. The virulence marker ACME was not detected in any of the isolates. Overall, a transition was found in hospital-associated MRSA isolates over the 25 years, but no introduction of community-associated MRSA isolates into this burn unit. Continued active surveillance and aggressive infection control strategies are recommended to prevent the spread of community-acquired MRSA to this burn unit.     

Community-Acquired Methicillin-Resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> in the Suburban Hand Surgery Patient Population

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause for patients to present to a physician’s office or emergency department. We observed increasing numbers of community-acquired MRSA infections in patients admitted to the hand surgery service at our suburban academic center. It is an important issue as unsuspected community-acquired MRSA hand infections can be admitted to the hospital, inadequately treated, and allowed for nosocomial spread. This study was performed to examine the trend in the incidence of community-acquired MRSA infections in patients admitted to the hand surgery service in order to sensitize practitioners to have a high index of suspicion for this entity and promote early recognition and treatment of this organism. A multihospital retrospective chart review was undertaken to compare the total number of community-acquired MRSA infections in our hospital as well as the number in patients admitted to the hand surgery service with community-acquired MRSA from 2000 through 2008. Statistical analysis was provided by linear regression. Two community-acquired hand MRSA infections were treated in 2000, as compared to three in 2001 and 2002, four in 2003, five in 2004, six in 2005, 14 in 2006, 13 in 2007, and ten in 2008. This increase was statistically significant (p = 0.038). This retrospective review documents a rapidly rising number of community-acquired MRSA hand infections in the suburban environment. The hand surgeon must be aware of the increased prevalence of this entity to adequately combat this organism and prevent prolonged hospital stays, expanded morbidity, and inflated treatment costs.     

Comparison of pathogens and antibiotic resistance of burn patients in the burn ICU or in the common burn ward

Background

This study aims to compare pathogens and their antibiotic resistances of burn patients from burn intensive care unit (ICU) or common burn ward. Of 2395 clinical samples from 63 patients in burn ICU, pathogens were detected in 1621 samples, in which 1203 strains (74.2%) were Gram negative bacteria, 248 strains (15.3%) were Gram positive bacteria, 170 strains (10.5%) were fungi. Top-4 microorganisms isolated from patients in burn ICU were Bauman's Acinetobacter (557, 34.4%), Pseudomonas aeruginosa (287.17.7%), Staphylococcus aureus (199, 12.3%) and Klebsiella pneumoniae (171, 10.5%). Of 512 clinical samples from 235 patients in common burn units, pathogens were detected in 373 samples, in which 189 (50.6%) strains were Gram negative bacteria, 150 strains (40.2%) were Gram positive bacteria, 34 strains (9.2%) were fungi. Top-4 microorganisms isolated from patients in common burn units were S. aureus (103, 27.6%), P. aeruginosa (46, 12.3%), K. pneumoniae (38, 10.2%) and Escherichia coli (32, 8.6%). Antibiotic resistance rates of pathogens isolated from clinical samples of burn patients from ICU was significantly higher than those from common units.

Conclusions

Pathogens and their antibiotic resistances are significantly different between burn ICU and common burn units. This finding has great implication for infection control in burn patients.     

Methicillin resistant Staphylococcus aureus in the critically ill

Methicillin resistant Staphylococcus aureus (MRSA) is endemicwithin many hospitals worldwide. Critically ill patients onintensive care units have increased risk factors making themespecially prone to nosocomially acquired infections. This reviewaddresses the current situation regarding the evolution of MRSAand the techniques for identifying and epidemiologically typingit. It discusses specific risk factors, the morbidity and mortalityassociated with critically ill patients, and possibilities forfuture antibiotic treatments. Br J Anaesth 2004; 92: 121–30     

Telavancin versus vancomycin for the treatment of complicated skin and skin-structure infections associated with surgical procedures

Background

We compared telavancin with vancomycin for the treatment of complicated skin and skin-structure infections (cSSSI) caused by Gram-positive bacteria.

Methods

This was a retrospective analysis of clinical and microbiologic efficacy assessed at test-of-cure (7 to 14 days after completing therapy) in 194 patients from 2 randomized, double-blind clinical trials comparing telavancin (10 mg/kg intravenous [IV] every 24 hours; n = 101) with vancomycin (1 g IV every 12 hours; n = 93) for the treatment of cSSSI.

Results

Baseline characteristics were similar for both treatment groups. Clinical cure and microbiologic eradication rates demonstrated consistent trends favoring telavancin over vancomycin; however, the differences were not statistically significant. The incidence of adverse events was mostly similar between groups.

Conclusions

The efficacy of telavancin was at least equivalent to that of vancomycin for the treatment of cSSSI. These data suggest that telavancin may be a useful alternative for treatment of cSSSI caused by S. aureus, particularly MRSA.     

A study on postoperative enteritis caused by methicillin-resistant Staphylococcus aureus

We investigated the production of staphylococcal enterotoxin (SE) with respect to coagulase types by methicillin-resistant Staphylococcus aureus (MRSA). A total of 138 strains of MRSA, which were isolated from clinical materials in the surgical ward between 1983 and 1990, were studied. Coagulase type IV strains produced SE A only, whereas coagulase type II strains were classified into four groups by SE production: SE B producing strains (32.7%), SE C producing strains (29.8%), SE B and C coproducing strains (12.5%), and SE A and C coproducing strains (25.0%). Almost all of the organisms (nine of ten) which were isolated from the feces of patients with MRSA enteritis were SE A and C coproducing strains. The coincidence in time of the prevalence of MRSA enteritis and the isolation SE A and C coproducing strains also demonstrated that these strains caused MRSA enteritis. Although SE C producing strains and SE A and C coproducing strains were simultaneously prevalent in 1990, the former tended to be sensitive while the latter tended to be resistant to minocycline. Considering the variety of antibiotic sensitivity in coagulase type II strains, it is thus considered to be of critical importance for epidemiologic purposes to further characterize isolates by SE typing.     

Geographic information system localization of community-acquired MRSA soft tissue abscesses

Background

Soft tissue infections with methicillin-resistant Staphylococcus aureus (MRSA) pose an ever-increasing risk to children in the community. Although historically these infections were limited to children with prolonged hospitalization, the authors have seen an increase in community-acquired infections in children without identifiable risk factors. The goal of this study is to determine the incidence of truly community-acquired MRSA soft tissue infections in our community and geographically map regions of increased risk.

Methods

After obtaining the institutional review board's approval, a retrospective chart review was conducted on 195 patients records who underwent an incision and drainage of soft tissue infections from January 1, 2000, to December 31, 2003. Thirteen patients were excluded from the study because no cultures were taken at the time of incision and drainage.

Results

The most common organism isolated from wound culture was S aureus, 40% (73/182), of which 45% (33/73) were MRSA. Eighty-one percent (27/33) of MRSA infections were in Springfield, 1 of 18 towns represented in the patient population. Geographic information system analysis identified a significant MRSA cluster 1.96 km in diameter within the city of Springfield.

Conclusions

Geography proved to be a significant risk factor for presenting with MRSA infection. Geographic maps of antibiotic resistance can be used to guide physician antibiotic selection before culture results are available. This has significant implications for the health care provider in proper antibiotic selection within the community.     

Incidence and bacteriology of burn infections at a military burn center

Considerable advancements in shock resuscitation and wound management have extended the survival of burned patients, increasing the risk of serious infection. We performed a 6-year review of bacteria identification and antibiotic susceptibility records at the US Army Institute of Surgical Research Burn Center between January 2003 and December 2008. The primary goal was to identify the bacteria recovered from patients with severe burns and determine how the bacteriology changes during extended hospitalization as influenced by population and burn severity. A total of 460 patients were admitted to the burn ICU with 3507 bacteria recovered from 13,727 bacteriology cultures performed. The most prevalent organisms recovered were Acinetobacter baumannii (780), Pseudomonas aeruginosa (703), Klebsiella pneumoniae (695) and Staphylococcus aureus (469). A. baumannii was most often recovered from combat-injured (58%) and S. aureus the most frequent isolate from local (46%) burn patients. Culture recovery rate of A. baumannii and S. aureus was highest during the first 15 hospital days (73% and 71%); while a majority of P. aeruginosa and K. pneumoniae were recovered after day 15 (63% and 53%). All 4 pathogens were recovered throughout the course of hospitalization. A. baumannii was the most prevalent pathogen recovered from patients with total body surface area (TBSA) burns less than 30% (203) and 30–60% (338) while P. aeruginosa was most prevalent in patients with burns greater than 60% TBSA (292). Shifting epidemiology of bacteria recovered during extended hospitalization, bacteriology differences between combat-injured and local burn patients, and impact of % TBSA may affect patient management decisions during the course of therapy.     

Antibiotic resistance and OXA-type carbapenemases-encoding genes in airborne Acinetobacter baumannii isolated from burn wards

The study was conducted to investigate drug resistance, OXA-type carbapenemases-encoding genes and genetic diversity in airborne Acinetobacter baumannii (A. baumannii) in burn wards. Airborne A. baumannii were collected in burn wards and their corridors using Andersen 6-stage air sampler from January to June 2011. The isolates susceptibility to 13 commonly used antibiotics was examined according to the CLSI guidelines; OXA-type carbapenemases-encoding genes and molecular diversity of isolates were analyzed, respectively. A total of 16 non-repetitive A. baumannii were isolated, with 10 strains having a resistance rate of greater than 50% against the 13 antibiotics. The resistance rate against ceftriaxone, cyclophosvnamide, ciprofloxacin, and imipenem was 93.75% (15/16), but no isolate observed to be resistant to cefoperazone/sulbactam. Resistance gene analyses showed that all 16 isolates carried OXA-51, and 15 isolates carried OXA-23 except No.15; but OXA-24 and OXA-58 resistance genes not detected. The isolates were classified into 13 genotypes (A-M) according to repetitive extragenic palindromic sequence PCR (REP-PCR) results and only six isolates had a homology ≥90%. In conclusion, airborne A. baumannii in the burn wards had multidrug resistance and complex molecular diversity, and OXA-23 and OXA-51 were dominant mechanisms for resisting carbapenems.