Anaerobic coverage for wound prophylaxis. Comparison of cefazolin and cefoxitin

An experimental wound model has been used to evaluate the effectiveness of cefazolin and cefoxitin in the prevention of wound infection. Incisions were contaminated with Staph. aureus, E. coli, or a standardized fecal suspension. Regardless of the contaminant employed, the prophylactic use of either cefazolin or cefoxitin yielded lower wound bacterial concentrations and fewer infections compared with treatment with placebo. Cefazolin proved just as effective as cefoxitin in preventing infection when wounds were contaminated with Staph. aureus or E. coli. Although cefoxitin is the only cephalosporin that offers anaerobic coverage, its prophylactic administration when wounds were contaminated with a standardized fecal suspension did not significantly alter wound bacterial concentrations or infection rates compared with cefazolin. The data from our animal wound model suggest that prophylactic anaerobic coverage is not necessary.     

Analysis of infection in a burn ward

One hundred and seventy-two burn wound swabs obtained from 90 patients admitted to the Aljila Hospital Burn Unit, Benghazi over a 3-month period were processed to determine the microbial flora colonizing burns and their resistance patterns to selected locally available topical and systemic agents. Approximately 84.9 per cent of the swab specimens yielded growth of 11 bacterial species and Candida spp.; of these, Ps. aeruginosa, Staph. aureus and Klebsiella spp. predominated in order of prevalence, followed by Enterobacteria. Polymyxin (100 per cent sensitive), amicacin (90.9 per cent sensitive) and carbenicillin (66.7 per cent sensitive) were the most effective of 10 selected antibiotics tested against the 60 pseudomonas isolates. In studies in vitro using six topical agents, Ps. aeruginosa strains were most sensitive, in decreasing order, to mafenide acetate, silver sulphadiazine, acetic acid, silver nitrate and Eusol. Seventy-eight per cent of Staph. aureus isolates were resistant to methicillin and erythromycin and 93 per cent to tetracycline.     

The use of immune RNA (i-RNA) to prevent and treat burn infection

The immune RNA was extracted from the spleens and livers of immunizing sheep with Ps. aeruginosa, E. coli and S. aureus. After animal trial, the i-RNA activity and its antibacterial protective effect has been demonstrated. 95 cases of burn infection treated with i-RNA plus antibiotics were compared with a concurrent control group treated with antibiotics alone. Clinical observation confirmed that an obvious effect on the prevention and treatment of burn infection with gram negative bacteria was manifested. Among them, 59 cases with burn area 15-49% II degrees, III degrees of total body surface, the ratio of incidence of gram negative septicemia and wound pyemia between i-RNA and control group was 1.69%: 22%, p less than 0.01. In another 36 cases with burn area over 50% body surface II degrees, III degrees treated with i-RNA the gram negative septicemia or wound sepsis were found in 3 cases (morbidity 8.3%). And one died overall mortality was 2.8%. Whereas, the morbidity and mortality were 51.4% and 45.9% respectively in 37 control cases. The ratio of morbidity between i-RNA and control group was 8.3%: 51.4%, p less than 0.01, and that of mortality was 2.8%: 45.9%, p less than 0.01.     

Studies in the management of the contaminated wound. VII. Susceptibility of surgical wounds to postoperative surface contamination

This study lends strong support to the thesis that wounds closed with tape are far more resistant to surface contamination than are wounds closed with percutaneous sutures. Immediate surface contamination with Staph aureus did not elicit an infection in any taped wound. Only 7.7 per cent of the taped wounds developed gross infection after contamination with E coli immediately after closure. Surface contamination with E coli two or more hours after closure did not result in infection in any taped wound.     

乳腺术后多重耐药菌感染分析与护理

目的分析乳腺术后多重耐药菌（MDRO）感染状况以及护理对策,以控制多重耐药菌感染的发生。 方法回顾性分析本科室2010至2014年收治的乳腺术后发生多重耐药菌感染的32例患者的临床资料,内容包括一般资料、病原菌微生物、感染部位和送检标本等。 结果病原菌中位于前3位的分别是金黄色葡萄球菌（12株、21.43%）,凝固酶阴性葡萄球菌（5株、15.63%）、肺炎链球菌（4株、12.5%）和铜绿假单胞菌（4株、12.5%）。送检标本分布和构成比分别为脓液28份（28.28%）,伤口泌物21份（21.21%）,痰液16份（16.16%）,静脉血14份（14.14%）,动脉血14份（14.14%）和组织6份（6.06%）。多重耐药菌感染的32例患者全部康复出院。 结论临床护理人员指导和监测多重耐药菌感染者,保持对MDRO警惕意识,严格遵守执行消毒隔离制度,仔细实施MDRO感染预防标准和手卫生规范,实施有效的护理措施能够减少MDRO感染,对MDRO感染者的康复有着非常重要的临床意义。     

Effects of physical configuration and chemical structure of suture materials on bacterial adhesion. A possible link to wound infection

The purpose of this study was to examine the effects of physical configuration and the chemical nature of suture materials on the preferential adherence of bacteria. Ten suture materials of 2-0 (chromic catgut, Dexon, Vicryl, PDS, Mersilene, Tycron, Ethibond, Surgilon, Ethilon, and Prolene) were used. The bacterial strains tested were Staph. aureus and E. coli. The level of bacterial adherence was determined quantitatively by radiolabelled cells and qualitatively by scanning electron microscopy. It was found that the amount of adhered bacteria depended on the type of suture material, the type of bacteria, and the duration of contact. In the group of absorbable sutures, the new PDS sutures exhibited the smallest affinity toward the adherence of both E. coli and Staph. aureus. Dexon sutures had the highest affinity toward these two bacteria. With nonabsorbable sutures, the physical configuration of the sutures contributed more to their ability to attract bacteria than the surface finish. The bacterial adherence on suture materials was also time dependent. Scanning electron microscope morphologic observation also indicated that Staph. aureus adhered on the suture surface in clusters whereas E. coli tended to adhere individually.     

Sensitivity of Staph aureus and Ps. aeruginosa and clinical application of antibiotics in patients with burn septicemia]

The sensitivity of 245 strains of Staph. aureus and 171 strains of Ps. aeruginosa to antibiotics was tested in patients with burn septicemia. The results indicated that both the bacteria were resistant to the widely used antibiotics. The causes for producing the resistance to drugs were analyzed. We consider that "circular therapy" of antibiotics, alternatively stopping and reusing some antibiotics according to the variation in the bacterial resistance to drugs, should be a valuable method for preventing the resistance to drugs.     

烧伤患者难愈性创面多重耐药菌回顾性分析

目的分析烧伤外科病房难愈性创面多重耐药菌（MDRO）定植感染情况，为临床感染防控提供依据。 方法对2012年1月至2017年12月中国人民解放军海军第九〇五医院烧伤外科住院患者难愈性创面的细菌学资料进行调查，回顾性分析MDRO的分布、检出率及特殊耐药情况。 结果难愈性创面分离出270株MDRO，其中革兰阳性菌128株（47.41%），革兰阴性菌142株（52.59%）。居前5位的MDRO依次为金黄色葡萄球菌（125株）、铜绿假单胞菌（56株）、大肠埃希菌（30株）、肺炎克雷伯菌（19株）和鲍曼不动杆菌（18株）。MDRO平均检出率为77.14%，以上前5位MDRO检出率分别为88.65%、65.12%、90.91%、100.00%和90.00%。特殊耐药菌株中，耐甲氧西林金黄色葡萄球菌共118株，碳青霉烯类耐药的铜绿假单胞菌、鲍曼不动杆菌和肺炎克雷伯菌分别为42株、12株和5株。 结论烧伤外科病房难愈性创面MDRO分布广泛、检出率高，应采取有效的感染防控措施。     

2003-2005年积水潭医院烧伤感染常见细菌及耐药性分析

目的 了解笔者单位近期的烧伤感染细菌分布及耐药情况。方法 收集2003年1月-2005年12月从笔者单位492例烧伤住院患者创面分泌物、静脉导管、血液、尿液、粪等标本分离而得的菌株，对其菌种分布特点及耐药性进行分析。结果 送检标本中革兰阴性菌多于革兰阳性菌。革兰阳性菌292株，分离率最高者为金黄色葡萄球菌（16．7％），其中甲氧西林耐药金黄色葡萄球菌在金黄色葡萄球菌中占82．5％；革兰阴性菌372株，分离率较高的分别为铜绿假单胞菌（12．5％）、大肠埃希菌（11．1％）。3年中大肠埃希菌和肺炎克雷伯菌对超广谱β内酰胺酶的耐药率分别为60．8％和42．9％。结论 笔者单位烧伤病区细菌耐药问题严重，仍需不断监测病区菌种变化及药物敏感情况，以有效地控制细菌感染和耐药菌株的播散。     

Treatment of full skin thickness burn injury using cultured epithelial grafts

This report presents the experience gained from 26 patients treated with autogenic cultured epithelial grafts (auto-CEG). All auto-CEG were applied to wounds clinically defined as full skin thickness injury. In total 89 separate sites were grafted. The overall estimate of ‘take’ ranged from 0 to 98 per cent with a mean value of 15 per cent. The highest level of ‘take’ (43 per cent) was observed when auto-CEG were applied to wounds which had been previously covered with allogenic split-thickness skin grafts. An increased incidence of wound colonization with pathogenic species of bacteria corresponded with a decreased graft ‘take’. Ps. aeruginosa and Staph. aureus were found to be present on 32.6 per cent and 60.5 per cent of wound swabs respectively, where 10 per cent or less ‘take’ of auto-CEG was seen, indicating that bacterial infection is in part responsible for graft failure. However, in 20.9 per cent of such instances, no growth of bacteria was detected, perhaps suggesting that certain wound beds may not present the correct physical environment necessary to support proliferating epithelial cells isolated from their underlying dermal component.     

伤口感染病原菌构成及耐药性分析

目的 了解我国创伤及术后伤口感染患者细菌分布及耐药状况.方法 采用纸片法、MIC法或E-TEST法,使用WHONET5.4软件进行分析,对卫生部全国细菌耐药性监测网所属86家三级甲等医院2006年6月1日至2007年5月31日分离的创伤及术后感染分泌物菌株进行分析.结果 (1)共分离细菌2125株,包括革兰阳性(G~+)菌994株(46.8%)和革兰阴性(G~-)菌1131株(53.2%),前三位细菌分别为葡萄球菌(780株、36.7%)、大肠埃希菌(338株、15.9%)和铜绿假单胞菌(231株、10.9%);(2)头孢西丁耐药的金黄色葡萄球菌和凝固酶阴性葡萄球菌的检出率分别为38.2%和84.1%,未发现对糖肽类耐药的葡萄球菌.(3)大肠埃希菌对三代、四代头孢萧素的耐药率约为60%～65%,对氟喹诺酮的耐药率为70%.(4)成人患者分离的葡萄球菌、大肠埃希菌对氨基糖苷类和喹诺酮类药物的耐药率明显高于儿童;(5)门急诊来源的葡萄球菌对头孢菌素、喹诺酮类、氨基糖苷类的耐药率明显低于住院患者来源细菌. 结论创伤及术后伤口感染的主要致病菌为葡萄球菌、大肠埃希菌和铜绿假单胞菌,MRSA检出率较同期整体监测细菌低,大肠埃希菌对头孢菌素耐药率较整体监测细菌高;成人分离菌耐药率高于儿童,门诊高于住院患者.     

Preliminary investigation of effect of pyocyanin on common bacteria in burn wound

Pyocyanin was extracted from culture medium of Ps. aeruginosa by Frank's method. Minimum inhibitory concentration (MIC) & minimum bactericidal concentration (MBC) of pyocyanin for 6 species of bacteria isolated from burn wounds were determined. The results of MIC & MBC: S. aureus 12.5 micrograms/ml, 50 micrograms/ml; E. coli 25 micrograms/ml, 100 micrograms/ml; P. vulgaris 50 micrograms/ml, 200 micrograms/ml; C. freundii 100 micrograms/ml, 400 micrograms/ml; S. epidermidis 12.5 micrograms/ml, 50 micrograms/ml; no inhibitory effect on Ps. aeruginosa. According to the laboratory results and clinical findings, the authors believe that when there is a dominant growth of Ps. aeruginosa in burn wounds there may be pyocyanin production to inhibit or kill other species of bacteria.     

Antimicrobial activity of lidocaine against bacteria associated with nosocomial wound infection.

The authors characterized the in vitro antibacterial properties of clinical doses of lidocaine on isolates of a variety of bacterial pathogens commonly encountered in the setting of nosocomial wound infection (Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) as well as a number of resistant strains of methicillin-resistant S. aureus and vancomycin-resistant enterococci. Time-kill studies were carried out on bacteria exposed to various clinical concentrations of lidocaine (0%, 1%, 2%, and 4%) with and without epinephrine (1:100,000). Minimum inhibitory concentrations and minimum bactericidal concentrations were determined for some strains using a broth macrodilution method recommended by the National Committee of Clinical Laboratory Standards. Lidocaine demonstrated a dose-dependent inhibition of growth for all strains of bacteria tested. The greatest sensitivity to lidocaine was shown by gram-negative organisms; the least sensitive was S. aureus. The addition of epinephrine to the local anesthetic had no effect on the susceptibility of the bacteria to lidocaine. These observations suggest that the surgical benefit of local anesthesia may extend beyond its analgesic properties and may have a role in the prophylaxis and, in the case of methicillin- and vancomycin-resistant bacteria, the treatment of surgical wound infection, mandating a wider application of this modality.     

下呼吸道感染的病原菌分布与耐药性分析

目的：分析临床下呼吸道感染病原菌构成及耐药情况,以指导临床医师合理应用抗菌药物.方法：分析2008年1月-2012年12月解放军总医院第一附属医院从痰（19 365份）、支气管灌洗液（4 203份）以及支气管肺泡灌洗液（302份）标本分离细菌的鉴定及药敏试验结果.结果：共分离出非重复病原菌10 635株,其中革兰阴性杆菌5 244株（49.3%）,革兰阳性球菌2 495株（23.5%）,真菌2 896株（27.2%）.未发现葡萄球菌属对万古霉素、替考拉宁和利奈唑胺的耐药菌株,发现3株大肠埃希菌和32株肺炎克雷伯菌对碳青霉烯类耐药菌株（CRE）,多重耐药铜绿假单胞菌（MDRPA）和鲍曼不动杆菌（MDRAB）分别占14.2%和46.3%.真菌以白色念珠菌为主,对抗真菌药较敏感.结论：下呼吸道感染分离的病原菌中鲍曼不动杆菌、铜绿假单胞菌和金黄色葡萄球菌是主要病原菌,同时耐碳青霉烯类的肠杆菌科细菌（CRE）以及耐万古霉素的肠球菌属（VRE）也是临床抗感染治疗的难点.     

An evaluation of the role of systemic antibiotic prophylaxis in the control of burn wound infection at the Lagos University Teaching Hospital

A prospective study was carried out on 61 patients to evaluate the role of systemic antibiotic prophylaxis in the control of burn wound infection. The patients were randomised into three groups: group 1 (n=21) received ampicillin and cloxacillin; group 2 (n=20) received erythromycin and genticin and a control group (n=20) received no systemic chemo prophylaxis. The burn wounds were similarly managed. Wound colonisation was determined from surface wound swab cultures and wound infection was determined from wound biopsy cultures and histopathology. The colonisation time (days) for the groups was 2.90+/-0.92, 3.15+/-0.77 and 3.05+/-0.83 for groups 1 and 2 and the control, respectively. The commonest organism isolated from contaminated wounds was Staphylococcus aureus. Wound infection was established in 5.70+/-1.70, 5.75+/-1.62 and 5.6+/-1.90 days for group 1, group 2 and the control group, respectively. There was no significant difference between wound infection time of control and group 1 nor was there such difference between the control and group 2 (P>0.05). The commonest organism infecting burn wounds in all the groups was Pseudomonas aeruginosa followed by S. aureus. There was however a significant difference between the treatment groups and the control (P<0.05) with regard to the percentage of infected wounds that grew P. aeruginosa, compared to those that grew S. aureus. It was concluded that systemic antibiotic prophylaxis is of no value in controlling burn wound sepsis, and might even favour the growth of P. aeruginosa in the burn wounds.     

难愈性创面感染的病原菌分布及定植感染相关因素

目的分析难愈性创面感染病原菌的分布及定植感染的相关因素,探讨相应的防治措施。 方法收集2012年至2015年本院烧伤外科难愈性创面感染者的临床资料,回顾性分析病原菌分布及定植感染相关的危险因素。 结果从难愈性创面感染中共分离出265株病原菌,其中革兰阳性菌116株（43.77%）,革兰阴性菌149株（56.23%）。常见的病原菌为金黄色葡萄球菌（104株,39.25%）、铜绿假单胞菌（71株,26.79%）和大肠埃希菌（28株,10.57%）。177例患者中138例有定植感染,39例无定植感染。单因素分析结果显示,创面面积（Z =－3.970、P < 0.001）、近日住院史（χ² = 5.865、P = 0.015）、住院时间超2周（χ² = 5.869、P = 0.0154）、低血红蛋白（χ² = 6.545、P = 0.011）、近期导管植入（χ² = 5.710、P = 0.017）、近期手术（χ² = 4.320、P = 0.038）和近期输液治疗（χ² = 10.023、P = 0.002）为病原菌定植感染的危险因素。多元回归分析结果显示,创面面积（OR = 1.516、95%CI：1.140~2.015,Waldχ² = 8.179、P = 0.004）为病原菌定植感染的独立危险因素。 结论本院烧伤外科难愈性创面感染分泌物病原菌中革兰阴性菌占优势,创面面积与病原菌定植感染密切相关。     

Duration of antibiotic prophylaxis. An experimental study

An animal wound model was used to evaluate single dose cefazolin, multiple dose cefazolin, and single dose cefonicid in the prevention of wound infection. Incisions made in Swiss-Webster mice were contaminated with either Staph. aureus (1.94 X 10(8) colony forming units) or E. coli (4.39 X 10(8) colony forming units). Five experimental groups were studied. Group I encompassed control animals given saline solution, Group II animals given 10 mg cefazolin preoperatively, Group III animals given 10 mg of cefazolin preoperatively and postoperatively, Group IV animals given 10 mg of cefonicid preoperatively, and Group V animals given 20 mg of cefonicid preoperatively. All medications were given by intraperitoneal injection. Antibiotics were given 1 hour before operation. Postoperative doses were given 4 hours after operation. Incisions were opened 48 hours after surgery and wound bacterial concentrations were determined. After both Staph. aureus and E. coli contamination, each of the four cephalosporin regimens significantly reduced the mean wound bacterial concentrations compared with that of the control animals (p less than 0.001). Each of the four cephalosporin regimens also significantly reduced the number of infected wounds compared with that of the control subjects (p less than 0.001). No significant differences were noted among the four antibiotic regimens with respect to mean wound bacterial concentration or infection rate. In the context of this model, a single dose of cefazolin seems to be equally effective as multiple doses of the drug for surgical prophylaxis. Extended half-life cephalosporins, like cefonicid, do not appear to be more effective than a single dose of cefazolin, which is a much less expensive antibiotic.     

Use of topically applied silver sulphadiazine plus cerium nitrate in major burns

All patients hospitalized between May 1987 and June 1988 suffering from burns covering over 50 per cent of the body surface area were treated by topical application of a cream containing cerium nitrate (0.05 M) and silver sulphadiazine (0.03 M) (CN + SSD). Eleven patients were included in this series, with a mean age of 35 years (range 22-65), a mean total burn size of 78 per cent (range 50-96 per cent) and full skin thickness covering a mean of 48 per cent (range 10-91 per cent). Eight patients survived (73 per cent) (mean age 36 years; mean total burn surface 73 per cent; mean full skin thickness burn surface, 38 per cent). These results are far better than those obtained in our Unit where a survival rate of 34 per cent was obtained in a comparable series of patients treated before 1987. Sixty positive blood cultures were obtained, which included a large variety of organisms with a slight predominance of Staph. aureus, Candida albicans and Ps. aeruginosa. Wound cultures were positive in 72 per cent of swabs and showed a predominance of Ps. aeruginosa (59 per cent of all the strains isolated). Even if CN + SSD appears in this series not to be very efficient in preventing wound colonization and septic complications, it permitted a very high survival rate in the treated patients, taking into account the extreme severity of the injuries. This beneficial effect is probably the consequence of the protective action of the yellow-green eschar formed by CN + SSD.(ABSTRACT TRUNCATED AT 250 WORDS)     

Investigation and analysis of the characteristics and drug sensitivity of bacteria in skin ulcer infections

Purpose: Skin ulcer is a common type of disease affecting patients'' health and quality of life, and bacterial infection increases the difficulty of its management. Methods: The present study collected the results of bacterial culture sampled from the surface of 110 cases of skin ulcers at our hospital from January 2011 to December 2012. We analyzed the constituent ratios of ulcer surface bacteria, the change in the main infectious bacteria and the results of drugsensitivity testing for common bacteria. In addition, the characteristics of bacterial infection of skin ulcers were summarized. Result: Of the 110 samples, 90 isolated bacteria were cultured. Sixty-one were Gram-negative bacteria, mainly comprising Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae and Escherichia coli. In addition, 23 isolates were Gram-positive bacteria, mainly comprising Staphylococcus aureus and Enterococcus faecalis. The probability of a negative bacterial culture in 2012 was significantly lower than that in 2011 (16.7% vs. 40.0%, p < 0.01). Moreover, the probability of P. aeruginosa infection in 2012 was significantly higher than that in 2011 (31.7% vs. 14.0%, p < 0.01). P. aeruginosa was resistant to seven commonly used antibiotics. Both K. pneumoniae and E. coli had higher resistance to ampicillin. E. cloacae were not sensitive to piperacillin/tazobactam. Acinetobacter baumannii was resistant to all the tested drugs. S. aureus, E. faecalis and Staphylococcus epidermidis had high resistance to clindamycin. There was other drug resistance to reflect the higher rate of skin bacterial resistance. Conclusion: Skin bacterial resistance rate is high. Gram-negative bacteria gradually account for the majority, and P. aeruginosa becomes the most important skin infection pathogen. These characteristics of bacterial infections of skin ulcers provide a significant reference for guiding the selection of antibiotics, better controlling infections of skin ulcers and accelerating the healing of skin ulcers.     

A variety of microorganism species at the burn ward

From 1975 to 1987, 965 exudate cultures of burn wounds were done in 553 cases. 1205 colonies (28 species) of microorganisms were separated out from these patients. Among 1205 colonies, 1050 colonies (87.13%) were "common microorganism" included P. aeruginosa, E. coli, S. aureus, and P. vulgaris. There were mixed infection of P. aeruginosa and E. coli in 23.66-25.95% cases. In early stage P. aeruginosa (23.25%) was predominant and in late stage, S. aureus was predominant. The sensitivity of microorganisms to 18 kinds of antibiotics gradually decreased, year by year. The authors consider that reasonable use of antibiotics, early eschar excision and skin grafting play an important role in decreasing the occurrence of drug-fast bacteria and preventing cross infection.