Large variations in clinical antibiotic activity against Staphylococcus aureus biofilms of periprosthetic joint infection isolates

Staphylococcus aureus biofilms have a high tolerance to antibiotics, making the treatment of periprosthetic joint infection (PJI) challenging. From a clinical perspective, bacteria from surgical specimens are cultured in a planktonic state to determine antibiotic sensitivity. However, S. aureus exists primarily as established biofilms in PJI. To address this dichotomy, we developed a prospective registry of total knee and hip arthroplasty PJI S. aureus isolates to quantify the activity of clinically important antibiotics against isolates grown as biofilms. S. aureus planktonic minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using clinical laboratory standard index assays for 10 antibiotics (cefazolin, clindamycin, vancomycin, rifampin, linezolid, nafcillin, gentamicin, trimethoprim/sulfamethoxazole, doxycycline, and daptomycin). Mature biofilms of each strain were grown in vitro, after which biofilm MIC (MBIC) and biofilm MBC (MBBC) were determined. Overall, isolates grown as biofilms displayed larger variations in antibiotic MICs as compared to planktonic MIC values. Only rifampin, doxycycline, and daptomycin had measurable biofilm MIC values across all S. aureus isolates tested. Biofilm MBC observations complemented biofilm MIC observations; rifampin, doxycycline, and daptomycin were the only antibiotics with measurable biofilm MBC values. 90% of S. aureus biofilms could be killed by rifampin, 50% by doxycycline, and only 15% by daptomycin. Biofilm formation increased bacterial antibiotic tolerance nonspecifically across all antibiotics, in both MSSA and MRSA samples. Rifampin and doxycycline were the most effective antibiotics at killing established S. aureus biofilms. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1604–1609, 2019.     

A retrospective analysis of biofilm antibiotic susceptibility testing: A better predictor of clinical response in cystic fibrosis exacerbations

BackgroundBacteria grow as biofilms within CF airways. However, antibiotic susceptibility testing is routinely performed on planktonically-growing bacteria. This study assessed whether CF patients infected with multiresistant organisms had improved clinical outcomes if given antibiotics that inhibited their biofilm-grown bacteria.Methods110 patients with pulmonary exacerbations were treated with intravenous antibiotics based on susceptibility testing of planktonically-growing bacteria. A retrospective analysis was done using bacterial isolates grown from their sputum at exacerbation. Each isolate was grown as a biofilm and combination antibiotic susceptibility testing was performed. Clinical outcomes in patients treated with biofilm-susceptible antibiotics were compared to those that were not.Results66 of 110 patients (60%) were treated with antibiotic combinations that inhibited all of their planktonically-grown bacterial isolates, however, when the same isolates were grown as biofilms, only 24 patients (22%) had all of their biofilm-grown isolates remaining susceptible to the antibiotics (P = < 0.001 ). When patients with at least one biofilm-grown susceptible isolate (n = 61) were compared to those with none (n = 49), there was a significant decrease in sputum bacterial density (P = 0.02) and length of stay (P = 0.04) and a non-significant decrease in treatment failure. Survival analyses of time to next exacerbation showed non-significant trends favoring patients treated with biofilm-effective antibiotics.ConclusionsMost patients with CF exacerbations do not receive antibiotics that inhibit all biofilm-grown bacteria from their sputum at exacerbation. Patients treated with biofilm-effective therapy seemed to have improved clinical outcomes.     

The antimicrobial efficacy of a silver alginate dressing against a broad spectrum of clinically relevant wound isolates

Wound dressings impregnated with silver have a role to play in aiding to reduce both the dressing and wound microbial bioburden. It is therefore imperative that antimicrobial wound dressings have efficacy on a broad range of clinical significant microorganisms. Accordingly, this study aimed to determine the antimicrobial efficacy of a silver alginate dressing against 115 wound isolates that had been isolated routinely from patients at West Virginia University Hospital. Standardised corrected zones of inhibition (CZOIs) were performed on all clinical isolates. It was found that the silver alginate dressing was able to inhibit the growth of all microorganisms tested. In particular, the silver alginate dressing inhibited the growth of Candida albicans and yeasts with CZOI of 3-11·5 mm. All meticillin-resistant Staphylococcus aureus (MRSA) strains were found to be sensitive to the silver alginate dressing with a CZOI range calculated at 3-7·8 mm. Sensitivity to the silver alginate dressing was also evident for S. aureus and vancomycin-resistant Enterococci. CZOIs of 4·25 mm were calculated for Enterococcus faecium and 9·8 mm for viridans streptococcus. The bacteria which demonstrated the highest tolerance to ionic silver included Enterobacter cloacae and Acinetobacter baumannii. Contrary to this the most responsive microorganisms to ionic silver included strains of staphylococci, viridans streptococcus and Candida albicans. No antibiotic-resistant isolates, as identified by Kirby Bauer Clinical Laboratory Standards Institute classification system, were found to be resistant to ionic silver. When a selected number of microorganisms were grown in the biofilm phenotypic state enhanced tolerance to silver was observed, compared to their non biofilm counterparts. Overall, this study has demonstrated the broad antimicrobial activity of a silver alginate dressing on wound isolates grown in the non biofilm and biofilm state. This finding is clinically relevant as both the non biofilm and biofilm phenotypic states of microorganisms are evident in wounds and therefore significant to delayed healing. Consequently, it is imperative that antimicrobial wound dressings demonstrate antimicrobial activity against microorganisms in both phenotypic states.     

The antimicrobial efficacy of silver on antibiotic-resistant bacteria isolated from burn wounds

The antibiotic‐resistant bacteria are a major concern to wound care because of their ability to resist many of the antibiotics used today to treat infections. Consequently, other antimicrobials, in particular ionic silver, are considered ideal topical agents for effectively helping to manage and prevent local infections. Little is known about the antimicrobial efficacy of ionic silver on antibiotic‐resistant bacteria at different pH values. Consequently, in this study our aim was to evaluate the effect of pH on the antimicrobial efficacy of a silver alginate (SA) and a silver carboxymethyl cellulose (SCMC) dressing on antibiotic‐resistant bacteria isolated from burn patients. Forty‐nine antibiotic‐resistant bacteria, including Vancomycin‐resistant Enterococcus faecium, meticillin‐resistant Staphylococcus aureus, multidrug‐resistant (MDR) Pseudomonas aeruginosa, MDR Vibrio sp, MDR Stenotrophomonas maltophilia, extended‐spectrum ß‐lactamase (ESBL) producing Salmonella sp, ESBL producing Klebsiella pneumoniae, ESBL producing Proteus mirabilis, ESBL producing Escherichia coli and MDR Acinetobacter baumannii, routinely isolated from burn wounds were used in the study and evaluated for their susceptibility to two silver containing wound dressings using a standardised antimicrobial efficacy screening assay [corrected zone of inhibition (CZOI)]. The mean overall CZOI for the Gram‐positive isolates at a pH of 5·5 were very similar for both dressings. A mean CZOI of 5 mm was recorded for the SCMC dressing, which was slightly higher, at 5·4 mm for the SA dressing. At a pH of 7·0 both dressings, in general, showed a similar activity. However, at a pH of 8·5 the mean CZOI of the SCMC dressing was found to be significantly (P < 0·05) higher than the SA dressing for a select number of isolates. The mean overall CZOI for the Gram‐negative bacteria followed a similar pattern as observed with the Gram‐positive bacteria. Susceptibility to silver ions did vary significantly between genera and species of bacteria. Interestingly, when pH was changed from 8·5 to 5·5 antimicrobial activity for both dressings in general increased significantly (P < 0·05). Overall, all forty‐nine antibiotic‐resistant bacteria isolated from burn wounds showed susceptibility to the antimicrobial activity of both silver containing wound dressings over all pH ranges. In addition, the study showed that the performance of both dressings apparently increased when pH became more acidic. The findings in this study may help to further enhance our knowledge of the role pH plays in affecting both bacterial susceptibility and antimicrobial activity of silver containing wound dressings.     

The efficacy of silver dressings and antibiotics on MRSA and MSSA isolated from burn patients

In this study our objectives were (1) to investigate whether meticillin‐resistant Staphylococcus aureus (MRSA) showed an increased tolerance to silver wound dressings compared with meticillin‐sensitive S. aureus (MSSA); and (2) to evaluate the effects of bacterial phenotypic states of MRSA and MSSA, and pH, on the activity of silver wound dressings and two antibiotics, ampicillin and clindamycin. Twenty MRSA strains and 10 MSSA strains isolated from burns patients in South Africa were evaluated for their susceptibility to a silver alginate and a silver carboxymethyl cellulose wound dressing, employing a corrected zone of inhibition assay, conducted on Mueller Hinton agar and a poloxamer‐based biofilm model. When exposed to the two silver dressings, all 30 S. aureus strains showed susceptibility. Possible enhanced antimicrobial efficacy of the silver dressings occurred when pH was lowered to 5.5, compared with a pH of 7.0. When all S. aureus were grown in the biofilm phenotypic state and exposed to both silver dressings and antibiotics, enhanced tolerance was noted. Susceptibility to silver was overall higher for MRSA when compared with MSSA. This study showed that the effect of pH and bacterial phenotypic state must be considered when the antimicrobial activity of silver wound dressings is being investigated. It is evident from the data generated that both pH and the bacterial phenotypic state are factors that induce changes that affect both antimicrobial performance and bacterial susceptibility.     

An in vitro biofilm model to examine the effect of antibiotic ointments on biofilms produced by burn wound bacterial isolates

Purpose

Topical treatment of burn wounds is essential as reduced blood supply in the burned tissues restricts the effect of systemic antibiotics. On the burn surface, microorganisms exist within a complex structure termed a biofilm, which enhances bacterial resistance to antimicrobial agents significantly. Since bacteria differ in their ability to develop biofilms, the susceptibility of these biofilms to topically applied antibiotics varies, making it essential to identify which topical antibiotics efficiently disrupt or prevent biofilms produced by these pathogens. Yet, a simple in vitro assay to compare the susceptibility of biofilms produced by burn wound isolates to different topical antibiotics has not been reported.

Methods

Biofilms were developed by inoculating cellulose disks on agar plates with burn wound isolates and incubating for 24 h. The biofilms were then covered for 24 h with untreated gauze or gauze coated with antibiotic ointment and remaining microorganisms were quantified and visualized microscopically.

Results

Mupirocin and triple antibiotic ointments significantly reduced biofilms produced by the Staphylococcus aureus and Pseudomonas aeruginosa burn wound isolates tested, as did gentamicin ointment, with the exception of one P. aeruginosa clinical isolate.

Conclusions

The described assay is a practical and reproducible approach to identify topical antibiotics most effective in eliminating biofilms produced by burn wound isolates.     

An investigation into the sensitivities of translocating bacteria to a prophylactic antibiotic regimen

INTRODUCTION: It is well established that bacterial translocation is associated with a significant increase in septic morbidity. The purpose of this study was to determine the antibiotic sensitivities of translocating bacteria on the basis that this information may influence antibiotic prophylaxis in surgical patients. METHODS: Routine microbiological techniques were used to assess the antibiotic sensitivities of those bacteria cultured from a mesenteric lymph node harvested at laparotomy in a large series of patients. RESULTS: Culture of the mesenteric lymph nodes yielded growth in 51 out of a total of 447 patients studied (11.4%). The isolates from 40 patients, a total of 60 organisms, were available for sensitivity testing. The most common species grown was Escherichia coli (48% of isolates). Thirty-three patients (83%) grew organisms sensitive to the antibiotic prophylaxis used, but there was no significant difference in the incidence of postoperative septic complications between these patients and those in whom resistant bacteria were grown (39% versus 29%, P = 0.64 Fisher's Exact test mid P). CONCLUSIONS: The majority of translocating bacteria are sensitive to the prophylactic antibiotics commonly used in patients undergoing laparotomy. However, the occurrence of postoperative septic morbidity is independent of this variable.     

1993～1996年1312株烧伤感染菌的耐药性调查分析

目的长期监测烧伤中心病房感染细菌的菌种和耐药率,以指导临床用药。方法应用VITEK-AMS系统检测1993-1996年我院烧伤中心1312株细菌的检出率及细菌耐药性变化。结果4年来检出菌种中铜绿假单胞菌居首位,检出率为31.16％-48.48％;金黄色葡萄球菌次之,检出率为11.48％～16.16％;其后为粪肠球菌、阴沟肠杆菌及不动杆菌等,但各年度位次不一。抗生素对铜绿假单胞菌敏感率超过50％者,1993年为7种,1994～1996年下降为4种。万古霉素对金黄色葡萄球菌(MR-SA)为100％敏感,而头孢菌素及喹喏铜类,对金葡菌均高度耐药(79％～86％)。结论长期监测烧伤中心致病菌种的变更,细菌药敏变化及选择应用敏感抗生素非常重要。     

1993～1996年1312株烧伤感染菌的耐药性调查分析

目的长期监测烧伤中心病房感染细菌的菌种和耐药率，以指导临床用药。方法应用ＶＩＴＥＫ－ＡＭＳ系统检测１９９３～１９９６年我院烧伤中心１３１２株细菌的检出率及细菌耐药性变化。结果４年来检出菌种中铜绿假单胞菌居首位，检出率为３１．１６％～４８．４８％；金黄色葡萄球菌次之，检出率为１１．４８％～１６．１６％；其后为粪肠球菌、阴沟肠杆菌及不动杆菌等，但各年度位次不一。抗生素对铜绿假单胞菌敏感率超过５０％者，１９９３年为７种，１９９４～１９９６年下降为４种。万古霉素对金黄色葡萄球菌（ＭＲ－ＳＡ）为１００％敏感，而头孢菌素及喹喏铜类，对金葡菌均高度耐药（７９％～８６％）。结论长期监测烧伤中心致病菌种的变更，细菌药敏变化及选择应用敏感抗生素非常重要。     

In vitro activity of tigecycline against resistant micro-organisms isolated from burn patients

Infections in burn patients are usually caused by multidrug-resistant micro-organisms. Tigecycline, a derivative of glycylcyclines, is an effective antibiotic against the resistant strains. The aim of this study is to determine the in vitro activity of tigecycline against the multidrug-resistant bacteria isolated from burn patients. Fourty-seven bacteria isolated from 118 patients hospitalized in the burn unit during 2003-2006 were included in the study. Gram-negative bacteria that were resistant to at least six broad-spectrum antibiotics, methicillin-resistant staphylococci and ampicillin-resistant enterococci were studied. Minimal inhibitory concentration values of tigecycline against these bacteria were tested by E-test strips. Susceptibility breakpoints were determined according to the previous studies; 相似文献   

Persistent and recurrent skin infection with small-colony variant methicillin-resistant Staphylococcus aureus

S. aureus is one of the problematic bacteria, capable to develop resistance mechanisms to all antibiotics that the bacteria are naturally susceptible. A particular phenotypic mechanism, especially against the antibiotics that repressed the synthesis of the cellular wall and aminoglycosides, was evidenced in subpopulations that grows in small-colonies and represents auxotrophic mutants for hemin, menadione or thymidine. This type of strains has been isolated most frequently from patients with osteomyelitis, septic arthritis or pulmonary infections after a long period of antibiotic treatment. The authors present the case of a patient with persistent and recurrent staphylococcal infection of the peritoneal dialysis exit site, treated with different antibiotics (ciprofloxacin, vancomycin, amoxicillin and clavulanic acid, cephalexin) from witch has been isolated a small-colony strain of methicillin-resistant S. aureus. Therapeutic failure can be explain by the slow multiplication of this strain in vivo, persistence into phagocytes and the protection offered by biofilm from the surface of the catheter. Bacteriologic diagnosis in these cases is difficult because of the culture, biochemical and susceptibility testing particularities of these strains. All these may lead failure to identification small colony variants of S. aureus and mis-evaluation of the frequency of infection with these strains in patients with long-term antibiotherapy.     

Antimicrobial susceptibility and ESBL prevalence in Pseudomonas aeruginosa isolated from burn patients in the North West of Pakistan

Pseudomonas aeruginosa is one of the most prevalent pathogen in burn infections. Infections with P. aeruginosa are associated with higher mortality rate and antibiotic costs in hospitalized patients. These bacteria also produce enzymes called Expanded Spectrum Beta-Lactamases (ESBL) which render penicillins and cephalosporins inactive. The aim of this study was to assess the antimicrobial susceptibility pattern and prevalence of ESBL in P. aeruginosa in Peshawar, North West of Pakistan. During 2005–2006, one hundred and six P. aeruginosa isolates were collected from burn patients at a tertiary care hospital. Antibiotic susceptibility testing and ESBL detection were carried out according to Clinical Laboratory and Standards Institute (CLSI) criteria. Eighteen antibiotics were tested in this study. A total of 38 (35.85%) isolates were found to be ESBL producers. Thirty one (29.24%) isolates were resistant to 3 or more antibiotics (multidrug resistance). Meropenem and imipenem showed high potency with 99% and 96% isolates being susceptible respectively. Susceptibility to amikacin was 70%; gentamicin 25%; ciprofloxacin 49%; enoxacin 47%; gatifloxacin 42%; doxycycline 21% and to co-trimoxazole only 16%. This study reveals that P. aeruginosa isolated from burns in this region are multidrug resistant and produce ESBL in large proportions.     

烧伤感染创面细菌及其药物敏感试验

本文收集和分析了1992年1月至1996年12月来院烧伤外科住院病人创面培养检出的各种细菌226株，以及它们对14种抗生素的敏感试验。结果表明，在引起烧伤创面感染的细菌中，革兰氏阴性菌明显多于革兰氏阳性菌；铜绿假单胞菌及金黄色葡萄球菌仍是烧伤病人创面感染的优势菌种；检出的这些细菌对多种抗生素耐药，临床治疗中应予以重视。     

A preliminary study of the relationship between antibiotic administration and changes in bacteriological profile of wound infection in a burn unit

Objective:To investigate the relationship between antibiotic administration and the changes in bacteriological profile in a burn unit. Methods: The data of consumption of different kinds of antibiotics, including total antibiotic consumption [expressed as the number of defined daily doses (DDD)] as well as pathogen identification, were collected in a 8-year period. The constituent ratios of different kinds of antibiotics in total antibiotic consumption to isolation rates of various species of bacteria were calculated, and their correlation was analyzed. Results: Within this period, it was found that the aminoglycosides and first generation cephalosporins were used less frequently, while the polypeptides, carbopenem and macrolides were used proportionally more. At the same time, the isolation rates of Staphylococcus aureus, Acinetobacter sp, Enterobacter cloacae, Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus were gradually increased. The constituent ratios of predominant pathogens were correlated to the different kinds of antibiotics consumption in the burn unit. Conclusion: The results suggested that the consumption of different antibiotics was closely related to the trends of emergence of bacterial isolates from infected burn wounds. The result might imply that to regulate the administration of certain antibiotics might help decrease the emergence of certain pathogenic bacteria in burn infections.     

1993～1999年烧伤科细菌学调查及耐药性分析

目的　研究笔者单位近几年细菌动态及耐药性 ,为临床诊治提供参考资料。　方法　对 1993～ 1999年本院烧伤科 784例患者的 345例次阳性创面细菌培养及药敏结果进行回顾性分析。　结果　 (1)革兰阴性 (G-)杆菌占 5 6 .8% ,革兰阳性 (G )球菌占 39.4 % ,真菌占 3.8% ;(2 )金黄色葡萄球菌占G 球菌的 6 5 .4 % ,其中耐药甲氧西林金葡菌 (MRSA)的分离率 1993～ 1999年为 5 3 9% ,1998～ 1999年为 6 4 .3% ;铜绿假单胞菌占G-菌的 37.2 % ;(3)第三代头孢菌素表现了良好的抗菌活性 ,但耐药率有明显增加 ;(4)万古霉素和去甲万古霉素对MRSA无 1例耐药。　结论　本院烧伤科细菌感染仍以G-杆菌为主 ,G 球菌次之。第三代头孢菌素是目前的常用抗生素 ,但耐药率增加的问题不容忽视。MRSA分离率有逐年增高的趋势 ,万古霉素和去甲万古霉素应作为首选用药     

The role of small-colony variants in failure to diagnose and treat biofilm infections in orthopedics

Biomaterial-related infection of joint replacements is the second most common cause of implant failure, with serious consequences. Chronically infected replacements cannot be treated without removal of the implant, as the biofilm mode of growth protects the bacteria against antibiotics. This review discusses biofilm formation on joint replacements and the important clinical phenomenon of small-colony variants (SCVs). These slow-growing phenotypic variants often remain undetected or are misdiagnosed using hospital microbiological analyses due to their unusual morphological appearance and biochemical reactions. In addition, SCVs make the infection difficult to eradicate. They often lead to recurrence since they respond poorly to standard antibiotic treatment and can sometimes survive intracellularly.     

Copal Bone Cement Is More Effective in Preventing Biofilm Formation than Palacos R-G

Bone cements loaded with combinations of antibiotics are assumed more effective in preventing infection than bone cements with gentamicin as a single drug. Moreover, loading with an additional antibiotic may increase interconnectivity between antibiotic particles to enhance release. We hypothesize addition of clindamycin to a gentamicin-loaded cement yields higher antibiotic release and causes larger inhibition zones against clinical isolates grown on agar and stronger biofilm inhibition. Antibiotic release after 672 hours from Copal bone cement was more extensive (65% of the clindamycin and 41% of the gentamicin incorporated) than from Palacos R-G (4% of the gentamicin incorporated). The higher antibiotic release from Copal resulted in a stronger and more prolonged inhibition of bacterial growth on agar. Bacterial colony counting and confocal laser scanning microscopy of biofilms grown on the bone cements suggest antibiotic release reduced bacterial viability, most notably close to the cement surface. The gentamicin-sensitive Staphylococcus aureus formed gentamicin-resistant small colony variants on Palacos R-G and therefore Copal more effectively decreased biofilm formation than Palacos R-G. Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.     

Species distribution and antibiotic sensitivity of bacteria isolated pre- and postoperatively from patients undergoing transurethral prostatic resection

The identity and antibiotic sensitivity of the isolated bacteria from 179 patients undergoing transurethral resection of the prostate were analysed. The patients were randomized into a group receiving a short course of cefotaxime in conjunction with the operation and a control group given no antibiotics. Preoperatively 70 patients had bacteriuria (greater than or equal to 10(7) CFU/l) with a predominance of Gram-negative bacteria (57 isolates, mainly Escherichia coli, Enterobacter, Klebsiella ssp, Proteus ssp), although Gram-positive species (24 isolates, mainly enterococci and Staphylococcus epidermidis) were also frequently encountered. Preoperatively isolated pathogens were evenly distributed in both groups and the sensitivity pattern was comparable. In the cefotaxime group postoperative recurrence of the preoperatively identified bacteria occurred in a lower frequency (11/43) than persistence in the control group (24/38). Only Gram-negative pathogens were isolated from patients with postoperative septicemia and upper urinary tract infections indicating that it is most important to direct prophylaxis against Gram-negative bacteria. A high degree of sensitivity against cefotaxime, gentamicin, trimethoprim, co-trimazine and a combination of ampicillin and mecillinam was recorded among both pre- and postoperatively isolated bacteria.     

南宁地区某烧伤病房细菌生态学调查及耐药性分析

目的　调查分析南宁地区某烧伤病房近15年来细菌生态学及耐药性的变化。　方法1989年4月—2004年3月,从笔者单位2 269例患者的血培养及创面培养物中分离出5 855株细菌,用K B法进行药物敏感试验。以每5年为1个阶段,分析各阶段标本的细菌检查及耐药情况。　结果　笔者单位烧伤患者感染以革兰阴性杆菌为主(3 559株占60. 79% ),其中铜绿假单胞菌、阴沟杆菌、硝酸盐阴性杆菌各阶段检出率较高;其次为革兰阳性球菌(1 990株占33. 99% ),以金黄色葡萄球菌、表皮葡萄球菌、凝固酶阴性葡萄球菌为主。各主要感染菌种对多种常用抗菌药物如庆大霉素、第三代头孢菌素、诺氟沙星、异丁基哌嗪利福霉素等的耐药率维持在较高水平或呈逐阶段上升趋势,而对临床少用的亚胺培南及万古霉素耐药率则很低。　结论　气候环境及抗菌药物的应用对细菌生态学的分布和耐药性的变化有直接影响。临床治疗中应合理使用抗菌药物。     

烧伤病房728株感染病原菌的分布特点及耐药性分析

目的了解笔者单位近5年烧伤感染病原菌的分布特点及耐药情况。方法收集2001-2006年笔者单位306例烧伤患者创面分泌物等标本中分离的病原菌，对其菌种分布特点及耐药性进行分析。结果革兰阳性菌378株，其中金黄色葡萄球菌的菌株数居首位，尤以甲氧西林耐药金黄色葡萄球菌居多，表皮葡萄球菌和粪肠球菌的菌株数分别位居第2、3位。革兰阴性杆菌338株，其中鲍氏不动杆菌的菌株数居首位，阴沟肠杆菌和铜绿假单胞菌的菌株数分别位居第2、3位。检出真菌12株。结论笔者单位病原菌的分布情况，可能与甲氧西林耐药葡萄球菌呈多重耐药性以及鲍氏不动杆菌产生各种类型的β内酰胺酶有关。