Bacteriological analysis of wound infection after open
fracture and control strategies
Author: JIANG Yuqing Chen Wei Wei Han Wei Xiang Hui Ye-guang
【Abstract】 Objective To study the wound infection after open fracture of the
bacteriological characteristics and guide anti-infective therapy. Methods from January
2003 to December 2007 admitted to our hospital 332 cases of postoperative infection in open fractures and the bacterial culture-positive cases, for bacteriological analysis and
drug susceptibility testing. Results wound infections of bacteria G-bacilli dominant
(69.58%), ranking first in isolated bacteria were Pseudomonas aeruginosa (accounting for 14.46%), G cocci accounted for first place in Staphylococcus aureus (accounting for
8.73%) Only Top fifth place. Vancomycin drug sensitivity of the bacteria the highest rate of G, while the G-bacteria were highly sensitive to imipenem. Conclusion wound infection after open fracture is still mainly G-bacteria, but bacteria types and virulence
change. Infection prevention and control is the key to reducing the incidence of nosocomial infections, while the results of bacteriological analysis should be based on the patients before and after a reasonable application of antibiotics.
Key words Treatment of open fracture wound infection Bacteriology
Wound infections are more common postoperative complications of open fractures, often extended treatment time and affect fracture healing and functional rehabilitation. With modern traffic accident injuries in the growing fracture of serious and extensive use of broad-spectrum antibiotics, resulting in wound infection and drug resistance of pathogenic bacteria in both kinds of changes. To study wound infection after open fracture of the bacteriological characteristics and guide anti-infective therapy, the
authors select from January 2003 to December 2007 admitted to our hospital 332 cases of postoperative infection in open fractures and the bacterial culture-positive cases, for
bacteriological analysis. Reported as follows.
A clinical data
1.1 General Information of this group of 332 cases, of which 217 cases of male and female 115 cases, aged 9 to 76 years (mean 39.5 years); infected with the longest 3 months, the shortest 10d; hospitalization longest 153d, shortest 15d, an average of 36.7 d. According to Gustilo classification, ?-type 21 cases, ? type 83 cases, ? in 228 cases.
1.2 inspection methods take aseptic samples (wound secretions, pus, accumulation of
blood, fluid, necrotic tissue, wound swab) sent to our hospital clinical laboratory. Bacterial culture and drug sensitivity test with biological - bioMérieux (Biomerieux)
Vitek32 automatic identification of susceptibility of bacteria were identified instrument.
2.1 The results of 332 cases of bacterial culture in patients with postoperative wound infection in open fractures of bacterial culture results, Gram-positive cocci 92 (27.1%),
Gram-negative bacteria 231 (accounting for 69.58%), fungi 9 (accounting for 2.71%) .
Table 1. Table 1 332 cases of postoperative wound infection in open fractures of bacterial culture results
2.2 The sensitivity test results shown in Table 2,3. Table 2 G major drug resistance in pathogenic Note: Value = sensitive strains / strains of a few × 100; / as not detected in Table 3 G-drug resistance in major pathogens
3.1 Bacteriological analysis of wound infection in the 20th century, the fifties and sixties before the devaluation of surgical infection pathogens Staphylococcus aureus and Streptococcus pyogenes; the seventies after the Gram-positive (G) gradually
Gram-negative bacteria (G - ) bacilli replaced by pathogenic bacteria showed change. At present, no significant change in this trend, and even has gradually increased. In this study, 332 cases of postoperative wound infection in open fractures types of bacteria to gram-negative bacilli, accounting for the total number of bacteria detected in 69.58%, followed by Gram-positive cocci accounted for 27.1%, which also Gustilo et al [2 ] and Zhangbo Song et al  reported that bacterial contamination of open fracture wounds mainly Gram-negative bacteria the same conclusion. In the detection of G-bacteria,
Pseudomonas aeruginosa detected the highest rate of 14.46%, followed by Escherichia coli (12.05%), calcium acetate complex Acinetobacter baumannii (11.45%) , Enterobacter cloacae (9.04%), were higher than G accounted for first place in bacteria Staphylococcus aureus (8.73%), Enterococcus faecalis (5.42%), Staphylococcus
epidermidis (4.52%) of the detection rate. In which scholars and other reports [3,4] The obvious difference is that calcium acetate Acinetobacter baumannii complex disease was significantly increased, exceeding the Enterobacter cloacae for the third G-
bacteria, fungal infection rate was 2.71 %, higher than Jisu Ling et al  reported that 0.9% has also been a large increase, which indicates that with the emergence of new types of broad-spectrum antibiotics and clinical large-scale, joint, prolonged and
unreasonable use of antibiotics, a number of pathogenic bacteria Xing also increases. Reposted elsewhere in the paper for free download http://
3.2 Analysis of susceptibility test results in G major pathogens was no vancomycin-
resistant cases, all of Staphylococcus aureus to penicillin G was 100% resistance rate, quinoline Nupu Ting / dalfopristin was 100% sensitive. In which coagulase-negative
staphylococci to oxacillin, ampicillin / sulbactam, cefazolin and other drug resistance
rate of 100%, Staphylococcus aureus and the above-mentioned drugs and clindamycin,
L ofloxacin, gentamicin resistance rates, etc. more than 50%. Enterococcus faecalis nitrofurantoin, penicillin G, levofloxacin high sensitivity. From the perspective of
antibiotics, the overall sensitivity rate for the G cocci ranked as vancomycin, quinoline Nupu Ting / dalfopristin, nitrofurantoin, levofloxacin, cotrimoxazole. G-pathogenic
bacteria in the Pseudomonas aeruginosa and Escherichia coli strains to imipenem,
amikacin, piperacillin / tazobactam have high sensitivity rate, but to other drugs, in particular is the first, third-generation cephalosporin resistance rates were higher, but not with Escherichia coli producing the same as easy ESBLs (extended spectrum β-
lactamase) and Klebsiella pneumoniae, although the two in this study, ESBL detection were 0, but there are significant differences in sensitivity to antibiotics, resistance rates among the lowest of all G-bacteria. Calcium acetate Acinetobacter baumannii complex
in all the G-resistant bacteria in the highest rate, in addition to 70% of the sensitivity of imipenem, the resistance rates to other drugs were "80%, coupled with its longer caused by the high infection rate, is worthy to pay close attention. Burkholderia cepacia
is 100% resistant to imipenem, piperacillin / tazobactam, cotrimoxazole was 100% sensitive. From the perspective of antibiotics, the overall sensitivity for the G-bacteria
ratio ranked as imipenem, amikacin, piperacillin / tazobactam, cefepime, levofloxacin .
It is worth noting is that belonging to the third generation of quinolones levofloxacin, though still on the G, G-bacteria have a strong bactericidal effect, but the rate of drug sensitivity in the ranking with other scholars, reported that [3 ], after the relative shift, consider quinolone drugs in the orthopedics infectious diseases and the extensive use of the drug resistant strains.
3.3 postoperative wound infection control strategies to open fracture wound
infection and contamination related to the number and types of bacteria. Bacteria, mainly through the direct adhesion with the wound tissue and the contaminated air flow the way wound contamination. Hospital emergency rooms, wards, operating theaters, debridement and placed between the utensils as well as medical staff in hand, exhaled gases, rooms and dressing rooms on the ground, bed sheets, pool and mops, rescue cars and trucks contain debridement except Enterobacter Division of Salmonella enteritidis and Shigella types outside the G, G-bacteria, especially bed
sheets, medical personnel hand, air, and dressing rooms on the ground the highest number of bacteria, and they come into contact with the patient up to . Most scholars believe that the open fracture wound contamination is hospital-acquired
infections, bacterial species is mainly G-bacteria [5,6], bacterial culture results of this
study also indirectly supports this view. This requires that the patient should be hospitalized numerous aspects of starting to take measures to reduce the incidence of
nosocomial infections. Such as the preoperative examination should minimize the exposure time of the wound using sterile dressing bandage, medical strict aseptic operation, intraoperative and thorough debridement and the use of a reasonable
surgical programs to minimize operative time, correctly handling the wound closure, intraoperative should pay attention to the wound dressing was changed after the treatment, strict disinfection and isolation ward system, at the same time do a good job
of disinfection and monitoring of the hospital environment. The rational use of antibiotics in open fractures as early as possible in order to reduce the incidence of infection has become a consensus report on the results of drug sensitivity before the
application of antibiotics to avoid a single small dose of long-term use of antibiotics
interfere with bacterial cell wall synthesis, multi-advocate broad-spectrum, joint, high-
dose medication, without causing damage to liver and kidney functions under the
premise of interference selection of bacterial protein, RNA synthesis of antibiotics. Author believes that, according to sources open fracture wound bacteria mainly G-
bacteria features, prevention of postoperative infection should be preferred drug
amikacin, followed by piperacillin / tazobactam. From the pharmacological analysis, both a fungicide for the breeding season (β-type amide), a fungicide for the quiescent
period (amino glycoside), play a synergistic role in combination, the best effect.
However, when access to drug sensitivity test results, clinicians should immediately based on this result, adjust the empirical treatment, a reasonable selection of antibiotics to treat sensitive to the effective prevention and control of postoperative wound
1 Yang Zhiming. Today the characteristics of orthopedic infections and countermeasures. Bone and joint injuries, 1999,14 (2): 139 ~ 141.
2 Gustilo RB, Merow RL, Templeman D. The management of open fractures. J Bone Joint Surg (Am), 1990,72:299 ~ 304.
3 Zhangbo Song, Zhai Guihua, Zhang Yalian, et al. Open fractures of bacteriology investigations and antibiotic selection. Zhonghua Surgery, 1998,36 (increase): 30 ~ 31.
4 Jisu Ling, Cheng Chi, Li Yaosheng, et al. 875 open fracture analysis of bacterial
infection of the wound. Journal of Practical Orthopedics, 2003,9 (2): 133 ~ 136.
5 Merritt K. Factors increasing the risk of infection in patients with open fractures. J Trauma, 1988,28 (6): 823 ~ 827.
6 Wu Xuedong, Han Dan, Ko Fai. Open fracture separation of infectious pathogens and drug resistance analysis. China Experimental diagnostics, 2006,10 (12): 1507 ~ 1508. Reposted elsewhere in the paper for free download http://www. hi138.com