Prevalence of multi and pan drug resistant Pseudomonas aeruginosa with respect to ESBL and MBL in a tertiary care hospital

Multi drug resistant Pseudomonas aeruginosa (MDRPA) and pan drug resistant Pseudomonas aeruginosa (PDRPA) isolates in critically ill patients are often difficult to treat. Prevalence of MDRPA and their antibiotic profile was investigated to select an appropriate empirical therapy. Moreover lack of sufficient data on prevalence of PDRPA in tertiary care hospitals indicated the need for this study. Pseudomonas aeruginosa was isolated in 245 patients over a period of one and half years from various clinical materials and their antibiotic profile was determined. Minimum inhibitory concentration (MIC) for Imipenem and Meropenam was determined by broth dilution method. Phenotypic confirmation test and EDTA double disk synergy test was used to detect Extended spectrum a-lactamase (ESBL) and Metallo-a-lactamase (MBL) producers respectively. Out of 245 isolates, 54 strains (22 %) and 11 strains (4%) were found to be MDRPA and PDRPA respectively. Carbapenem resistant isolates showed MICs ranging from 16 to > 64 microg/ml. Thirty eight strains (15.5%) were ESBL producers and six (54.5%) among 11 PDRPA were MBL producers. Prevalence of MDR and PDR isolates of Pseudomonas aeruginosa was found to be 22% and 4% respectively, which is less compared to other studies. Majority of the PDRPA isolates were MBL producers which have propensity to spread to other bacteria.     

老年人亚胺培南耐药铜绿假单胞菌耐药性研究

目的 明确我院老年病人临床分离铜绿假单胞菌的耐药性、同源性及耐碳青霉烯菌株的基因型。方法 收集我院2006年5月-2009年5月自临床老年病人分离的262株铜绿假单胞菌,纸片扩散法测定其对16种抗菌药物的耐药性;琼脂稀释法和E test法测定耐碳青霉烯菌株对14种抗菌药物的MIC值,PCR扩增及克隆测序分析金属酶基因型。脉冲场凝胶电泳(PFGE)分析携带金属酶基因型菌株的同源性。结果 262株铜绿假单胞菌中筛选到104株耐碳青霉烯。104株耐碳青霉烯铜绿假单胞菌对氨苄西林/舒巴坦、头孢哌酮/舒巴坦两个含舒巴坦制剂药物耐药率分别为78.9％和35.9％,对多黏菌素E耐药率最低为6.0％,对米诺环素耐药率58.3％,其余抗菌药物耐药率均大于70.0％;104株亚胺培南耐药铜绿假单胞菌中12株携带金属酶基因,10株检测到有携带VIM-2基因的1类整合子。PFGE分型中12株菌株属于5个克隆株。结论 在我院流行的亚胺培南耐药铜绿假单胞菌中,金属酶基因不是最主要的基因型,金属β-内酰胺酶均为VIM-2型金属酶,耐药基因盒分布于不同的1类整合子中,整合子播散是最主要的流行方式。     

In vitro comparative activity of kanamycin, gentamicin and sisomicin--a new aminoglycoside, against clinical isolates

540 strains of bacteria isolated from various clinical materials comprising 440 strains of Gram negative bacilli and 100 strains of Gram positive cocci were tested for their susceptibility in vitro to Kanamycin, Gentamicin and a new aminoglycoside antibiotic Sisomicin (Ensamycin). The sensitivity pattern revealed that 68.88% of the strains were sensitive to Kanamycin, 82.9% to Gentamicin and 89.0% to Sisomicin. The effectiveness of Sisomicin is comparatively greater (6.1%) than the other two aminoglycosides. In particular a considerable number of Gentamicin resistant Pseudomonas aeruginosa (12.3%) were found to be sensitive to Sisomicin which is a highly desirable property. Existence of about 11% Sisomium resistant strains even before the wide usage of this antibiotic is note worthy.     

烧伤病房内小儿烧伤创面感染病原菌调查及抗生素敏感性分析

目的分析烧伤病房内小儿烧伤创面感染细菌分布及抗生素敏感情况。 方法收集2010年1月至2017年12月期间安徽医科大学第一附属医院烧伤科病房内符合入选标准的小儿住院烧伤患者共170例。对患儿创面分泌物做细菌培养及药物敏感试验,对菌种分布特点及抗生素敏感性进行分析。 结果共检出138株病原菌。其中革兰阴性杆菌以铜绿假单胞菌、鲍氏不动杆菌及大肠埃希菌为主,分别为39株(28.3%)、22株(16.0%)、14株(10.1%);革兰阳性球菌以金黄色葡萄球菌25株(18.1%)、溶血葡萄球菌14株(10.1%)为主。另外检出的金黄色葡萄球菌中均为耐甲氧西林金黄色葡萄球菌,仅对替加环素及万古霉素的药物敏感率为100%,对利奈唑胺及喹努普汀-达福普汀的敏感率分别为96.0%、80.0%。检出的铜绿假单胞菌对多粘菌素B及米诺环素的药物敏感率为100%,鲍曼不动杆菌对替加环素及多粘菌素B的敏感率为100%。 结论在安徽医科大学第一附属医院烧伤小儿住院患者创面感染的菌株前三位分别是铜绿假单胞菌、金黄色葡萄球菌及鲍曼不动杆菌。以革兰阴性杆菌感染为主,并呈现出多重耐药性,只对少数抗生素敏感。建议在预防医源性感染、监测细菌药物敏感情况的条件下,合理应用抗生素。     

我院重症监护室铜绿假单胞菌感染趋势及其耐药性分析

目的铜绿假单胞菌（Pseudomonas aeruginosa,PA）为院内感染的重要代表菌及临床分离率较高的菌株,在我院PA占所有菌株检出率的24.5%、占革兰阴性杆菌检出率的35.4%。通过对我院2006年1月-2009年6月期间4个重症监护室铜绿假单胞菌的感染情况及其耐药性进行分析,并与同期非重症监护室的病区进行比较,分析PA产碳青霉烯酶水解碳青霉烯类抗生素后同时携带多种耐药基因对其他药物敏感性的影响。方法采用Micro Scan全自动细菌鉴定和药敏分析仪,数据的分析采用WHONET软件。结果 4年间我院重症监护室铜绿假单胞菌检出数为559株,依次为：内科ICU272株、外科ICU149株、急诊ICU126株、儿科ICU12株。药敏结果显示：铜绿假单胞菌对大部分抗生素的敏感性呈逐年下降的趋势,尤其是重症监护室感染菌株。PA对碳青霉烯类抗菌素耐药的菌株产生多重甚至广泛耐药的几率较高。结论 4年间我院重症监护室铜绿假单胞菌对抗生素的耐药状况严重,尤其对头孢菌素,氨基糖苷类抗生素耐药率明显增加。对亚胺培南的耐药株同时携带多种耐药机制,产生多重耐药甚至泛耐药。多重耐药株和泛耐药株的检出亦呈逐年上升的趋势。     

Evaluation of a new E-test method for antimicrobial sensitivity testing of Pseudomonas aeruginosa isolates from cystic fibrosis

BACKGROUND: Sputum bacteriological analysis of cystic fibrosis (CF) patients colonised by Pseudomonas aeruginosa is difficult. The bronchial persistence of these bacteria involves phenotypical modifications and the many antibiotic treatments result in emergence of multiresistant strains. The aim of this study is to evaluate a new fast identification and sensitivity testing method of P. aeruginosa and other pathogenic bacteria in sputum of CF patients. It is based on applying a gradient of antibiotic (E-test strip) onto an agar plate inoculated with the sputum. OBSERVATIONS: 310 sputum, collected from adults and children colonised by P. aeruginosa, were analysed by this new method. This method allowed a direct reading of the minimal concentration of antibiotic that inhibited the totality of Gram-negative strains and the detection of resistant pathogenic bacteria inside the ellipse of inhibition. Results obtained by this new method were compared with the conventional method for identification and antimicrobial sensitivity. CONCLUSION: This new method, studying with CF patient colonised by P. aeruginosa, appears interesting, with a sensibility equal or higher than 89% in detection of the bacteria and their sensitivity to antibiotics. Furthermore it allows a saving of time and simplified results.     

赣南地区临床分离菌耐药性变迁及多重耐药菌的流行变化

目的 了解赣南地区2013年~2016年临床分离的主要病原菌分布和多重耐药菌的流行变化。方法 采用梅里埃Vitek 2 compact对分离的菌株进行鉴定药敏。结果 4年内共分离41288株细菌,革兰阴性菌所占比例最高（67.00%）。病原菌分布中大肠埃希菌、鲍曼不动杆菌、铜绿假单胞菌、肺炎克雷伯菌、金黄色葡萄球菌位居前五。阿米卡星、哌拉西林/他唑巴坦对肠杆菌科细菌具有较高的的敏感性,鲍曼不动杆菌对多种常用抗菌药物呈现高水平耐药;铜绿假单胞菌对大部分抗菌药物较敏感,未检出万古霉素、利奈唑胺耐药的菌株。4年间耐甲氧西林金黄色葡萄球菌的检出均在25.00%以上;耐碳青霉烯肠杆菌科细菌的检出由2.90%上升至4.70%;耐碳青霉烯鲍曼不动杆菌的检出逐年下降。结论 赣南地区CRE的检出不断上升,临床应根据药敏合理选用抗菌药物,采取有效防控措施减缓多重耐药菌的产生。     

铜绿假单胞菌的药物敏感试验结果分析

目的了解铜绿假单胞菌在本院的分布及对抗生素的敏感情况,为临床治疗提供科学依据。方法回顾性调查本院2008年1月至2009年10月住院及门诊患者各种标本分离的铜绿假单胞菌的分布及对抗生素的敏感情况。结果铜绿假单胞菌在呼吸道标本的检出率最高,占63.8%,其次是伤口分泌物标本,占18.3%,尿液标本占9.2%,血液标本占2.5%;其对11种抗生素的敏感率最高是妥布霉素,其次是哌拉西林/他唑巴坦,检出多重耐药株约占35%,未出现泛耐药株。结论根据药敏结果合理使用抗生素,并重视对多重耐药株的监测工作,可有效控制感染。     

Detection of Pseudomonas cytochrome oxidase and esterase in blood culture broths

Search for cytochrome-oxidase was performed directly on blood culture broths without prior isolation of the pathogen on agar, using paper disks impregnated with "oxidase" reagent and the Api Z strip which enables additional detection of esterases. Both these tests are indicative of the presence of Pseudomonas. False-positive results were recorded in only 0.65% of the 167 strains of Enterobacteria studies. The 38 strains of Pseudomonas aeruginosa gave 5.26% false-negative results; 88.6% of Pseudomonas strains were esterase-positive. Simultaneous search for both these enzymes thus allows for identification and antibiotic sensitivity testing before agar isolation.     

产ESBLs、AmpC、KPC酶的葡萄糖不发酵细菌的耐药性分析及临床分布

目的了解本地区葡萄糖不发酵细菌中泛耐药菌（代表株铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌）在临床标本中的分离与耐药情况,为临床合理使用抗生素提供指导。方法对临床分离的180株葡萄糖不发酵细菌进行分类鉴定和药敏试验,并用纸片扩散法筛选出产超广谱β-内酰胺酶（ESBLs）、头孢菌素酶（AmpC酶）及碳青霉烯类水解酶（KPC酶）的耐药菌株。结果在葡萄糖不发酵细菌的构成比中,其中产超广谱β-内酰胺酶（ESBLs）56株（31.1%）,产AmpC酶22株（12.2%）,KPC酶2株（1.1%）;同时产ESBLs和AmpC酶16株（8.9%）,同时产ESBLs、AmpC、KPC酶1株（0.6%）。3种主要葡萄糖不发酵细菌对头孢他啶、头孢三嗪、头孢噻肟、哌拉西林的耐药率最高,其中铜绿假单胞菌对阿米卡星、左氧氟沙星、环丙沙星耐药率较低,鲍曼不动杆菌对亚胺培南、左氧氟沙星耐药率较低,嗜麦芽窄食单胞菌对复方新诺明、环丙沙星耐药率较低。结论葡萄糖不发酵细菌中泛耐药菌特别是铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌均有较高的多重耐药性,临床上应重视葡萄糖不发酵细菌引起的感染,根据药敏试验结果合理使用抗生素。     

河源地区铜绿假单胞菌碳青霉烯耐药机制分析

目的研究本院铜绿假单胞菌耐碳青霉烯类抗生素的耐药现况及主要耐药机制。方法用E-test方法检测铜绿假单胞菌对哌拉西林、头孢他啶、亚胺培南、美洛培南、庆大霉素、妥布霉素、环丙沙星7种抗生素的最小抑菌浓度,用EDTA双纸片扩散法及三维实验分别对金属酶及AmpC、KPC酶表型进行确证。结果从1 068例致病菌中共分离出108例铜绿假单胞菌,18例是对亚胺培南和/或美罗培南不敏感的菌株,耐药率为16.7%,其中有9例金属酶确证实验阳性,3例为AmpC酶持续高产型菌株,KPC酶确证实验尚没有检测出阳性菌株。结论耐碳青霉烯类铜绿假单胞菌多表现为多重耐药,这是多因素共同作用的结果 。     

神经内科重症监护病房医院获得性肺炎 病原菌分布及耐药性分析

目的 探讨神经内科重症监护病房医院获得性肺炎的病原菌分布以及对抗生素的耐药性,为抗感染治疗提供参考。方法 2016年1月~2017年12月入住湖南省第二人民医院神经内科重症监护病房合并院内获得性肺炎的患者79例,采集痰标本进行细菌分离及培养,并对其进行相关药敏试验。结果 共分离出89株病原菌,其中革兰氏阴性菌占87.64%,革兰氏阳性菌10.11%,真菌2.25%。病原菌以鲍曼不动杆菌（24.72%）、肺炎克雷伯菌（19.10%）、铜绿假单胞菌（17.98%）,金黄色葡萄球菌为主（8.99%）为主;鲍曼不动杆菌对大部分抗菌药物耐药,铜绿假单胞菌对头孢哌酮舒巴坦和头孢他啶的耐药率较高,肺炎克雷伯菌耐药率低。金黄色葡萄球菌对青霉素耐药率高。结论 HAP致病菌以革兰氏阴性菌为主,其中鲍曼不动杆菌耐药严重,同时也应注意革兰氏阳性菌和真菌感染。     

Etiologic factors of pleural empyema as a potential source of nosocomial infections

Pleural empyema still comprises an important therapeutic problem despite the availability of effective antibiotic therapy. This disorder is characterised by 20% mortality rate. Moreover, the involvement of multi-drug resistant bacterial strains may pose a risk of a nosocomial spread to other hospitalised patients. In the present study we have analysed 184 bacterial strains isolated from 63 patients with pleural empyema. A predominance of aerobic bacteria was detected, both Gram-positive cocci and Gram-negative bacilli. Staphylococci isolated from the clinical samples were characterised by a high percentage of strains resistant to gentamicin (86.3%) and methicillin (38.2%). The other important etiological agents were Pseudomonas aeruginosa and Gram-negative enteric rods of the Enterobacteriaceae family. Only 1 strain of anaerobic bacteria was detected. The enteric bacilli were characterised by a low percentage of isolates susceptible to most of the tested antibiotics (< 60%), with an exception of ciprofloxacin (68%) and imipenem (100%). These multi-drug resistant strains may spread nosocomially to other patients.     

An in vitro evaluation of antibiotic combinations for urinary tract infections in patients with diabetes mellitus

This prospective in-vitro study evaluates the synergistic potential of various antibiotic combinations against resistant pathogens isolated from urinary tract infections (UTIs) in patients with diabetes mellitus. Antibiotic combinations using the microtiter checkerboard method showed that overall, synergy could be seen in 41.86%-67.44% cases amongst the five different antibiotic combinations studied against the four predominant resistant pathogens namely Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella ozaenae. The checkerboard synergy studies showed that 69.23% of the S. aureus strains tested were synergistically inhibited by the combination of ofloxacin + cefotaxime [OF+CF], 83.33% of the E. coli strains and 75% of the K. ozaenae strains were synergistically inhibited by the combination of amikacin + cefotaxime [AK+CF], while 58.33% of the P. aeruginosa strains were synergistically inhibited by the combination of amikacin + piperacillin [AK+PP].     

In vitro study of the combination of pefloxacin with other antibiotics against Pseudomonas aeruginosa and Streptococcus group D

The comparative susceptibility of 50 isolates of enterococci and 50 isolates of Pseudomonas aeruginosa to pefloxacin and different antibiotics was tested using MIC determination. The results showed only 6% sensitive strains of enterococci and 36% of P. aeruginosa. The high level resistant streptococci against aminoglycosides and resistant Pseudomonas strains have weakly higher MIC than sensitive strains. The activity of the combination of pefloxacin and other antibiotics was determined by a checkerboard micromethod. Fractional concentration index (FIC and FBC) show most frequently addition, uncommonly synergy.     

Sensitivity of Pseudomonas aeruginosa to sulphonamides and trimethoprim and the activity of the combination trimethoprim: sulphamethoxazole.

The activities of three sulphonamides and trimethoprim against strains of Pseudomonas aeruginosa have been studied. Sulphadiazine had most activity, sulphadimidine had little, and the activity of sulphamethoxazole was intermediate. According to their sensitivity to sulphamethoxazole, strains were divided into two groups: "highly resistant" (16%, MIC greater than 1000 microgram per ml) and "moderately resistant" (84%, MIC less than or equal to 1000 microgram per ml). The former were resistant on disk testing to Sulphatriad 300 microgram. Sulphamethoxazole and trimethoprim did not act in synergy against them. The moderately resistant strains were sensitive to Sulphatriad; trimethoprim and sulphamethoxazole showed marked synergy against them in agar-plate dilution tests. The concentrations of trimethoprim and sulphamethoxazole necessary for synergy lay for each drug within the range of concentrations at which they have been found in urine, and the ratio of their MICs when acting in synergy was similar to the ratio of their concentrations in urine. It is suggested that a disk containing trimethoprim and sulphamethoxazole in a ratio of 1 : 2 rather than 1 : 20 would be more appropriate when testing strains from urine for their sensitivity to co-trimoxazole.     

Transfer of plasmid-mediated antibiotic resistance in strains of Pseudomonas aeruginosa isolated in Auckland.

Of 422 clinical strains of Pseudomonas aeruginosa, 23 (5.5%) were resistant to gentamicin; 19 were also resistant to tobramycin and sisomycin, and one was resistant to tobramycin, sisomycin and amikacin. Of the gentamicin-resistant strains, 20 were also resistant to kanamycin. Sixteen strains with a high level of resistance to gentamicin (MIC greater than 160 microgram/ml) transferred all their resistance determinants to recipient strains of P. aeruginosa and four transferred some resistance determinants to P. aeruginosa but none transferred resistance to a recipient strain of E. coli K12. These results show that gentamicin resistance in strains of P. aeruginosa isolated in Auckland is mediated by R plasmids.     

Gram-negative bacilli in burns

In a period of two years, 865 strains of Gram-negative bacilli other than Pseudomonas aeruginosa isolated from burns were identified by a range of tests. The commonest species were Proteus mirabilis, Escherichia coli, and Enterobacter cloacae. Many strains of Klebsiella aerogenes, Enterobacter aerogenes, and Bacterium anitratum were also found.A large proportion of the strains were tested for sensitivity to nalidixic acid, ampicillin, kanamycin, chloramphenicol, tetracycline, and carbenicillin, and smaller numbers of strains were tested for sensitivity to cephaloridine, polymyxin, streptomycin, sulphadiazine, sulfamylon, and trimethoprim. The proportion of strains sensitive and resistant to different antibacterial agents varied widely with species of bacteria. A large proportion of the strains of E. coli and P. mirabilis were resistant to ampicillin, which was much used in treatment; resistance appeared least often towards nalidixic acid, kanamycin, trimethoprim, and gentamicin. Multiple resistance occurred less often among strains of E. coli than among Klebsiella spp, Enterobacter spp, and P. mirabilis.Phage and serological typing of Ps. aeruginosa showed that most infections of burns with this organism were due to strains previously found in other patients in the same ward. Taken with other evidence, this supported the view that most infections with Ps. aeruginosa were not acquired from the patient's own flora but from sources in the hospital environment.     

广州地区2003—2007年499株铜绿假单胞菌的耐药性分析

目的了解广州地区铜绿假单胞菌对常用抗菌药物的耐药状况,以指导临床合理选用抗生素。方法收集广州市7家三甲医院2003—2007年分离的499株铜绿假单胞菌,利用VITEK-32全自动微生物鉴定系统对所有收集的菌株进行种属鉴定,参照美国临床和实验室标准化协会（CLSI）推荐的方法,分别采用K—B法和琼脂稀释法进行药敏试验,用WHONET5．4软件分析铜绿假单胞菌的耐药性,用SPSS11．5软件进行统计分析。结果499株铜绿假单胞菌其抗生素耐药率依次为庆大霉素（42．0％）、阿米卡星（36．6％）、亚胺培南（32．8％）、头孢吡肟（28．3％）、头孢他啶（27．1％）、美罗培南（21．4％）、氨曲南（20．5％）、哌拉西林（8．8％）、哌拉西林／三唑巴坦（8．3％）、左旋氧氟沙星（8．1％）和环丙沙星（7．6％）;2003—2007年5年期间铜绿假单胞菌对亚胺培南的耐药率分别是27．7％、25．0％、31．6％、35．2％和34．3％,对美罗培南的耐药率分别是22．2％、21．O％、21．2％、19．7％和24．5％。结论2003—2007年广州地区铜绿假单胞菌整体耐药现象严重,对氨基糖苷类、碳青霉烯类和头孢菌素类抗生素高度耐药,仅对喹诺酮类和青霉素类抗生素较为敏感。因而加强其耐药性监测不仅可以指导临床合理选用抗菌药物．而且还能为临床提供最新的流行病学和耐药性变迁资料。     

天津地区某基层医院铜绿假单胞菌的5年耐药变迁

目的 观察天津地区某基层医院铜绿假单胞菌的临床分布及其耐药情况和近5年的耐药变化趋势,为临床抗感染治疗的经验用药和合理使用抗生素提供理论依据。方法 收集2013年1月~2017年12月我院住院患者细菌培养标本分离的铜绿假单胞菌,分析其科室分布及菌株对临床常用抗菌药物的耐药率和耐药变迁。结果 5年内共分离到铜绿假单胞菌542株,其分布主要以呼吸内科、ICU以及普通外科为主。铜绿假单胞菌对氨曲南、左氧氟沙星、头孢他啶、亚胺培南、美罗培南、哌拉西林他唑巴坦、阿米卡星的耐药率分别为28.80%、17.30%、15.40%、13.30%、15.30%、8.30%、3.60%。结论 铜绿假单胞菌是基层三级综合医院临床科室最常见的革兰阴性非发酵菌,分离人群主要以呼吸内科、ICU和普通外科为主。我院分离的铜绿假单胞菌对大多数临床常用抗菌药物均有较好的体外敏感性。因此,临床使用这些药物治疗铜绿假单胞菌感染通常可获得良好的疗效。但由于该细菌易产生获得性耐药,且近年来少数抗菌药物的耐药率波动范围较大。因此建议临床医生关注实验室药敏结果报告和细菌耐药监测报告。