Antibiotic resistance among Salmonella from human and other sources in New Zealand

Of 2210 salmonella isolates referred to the New Zealand Communicable Disease Centre for epidemiological surveillance during 1987, 147 (6.7%) were resistant to one or more of 10 antibiotics. Resistance to streptomycin was most common (4.5%), followed by sulphamethoxazole (3.4%), tetracycline (3.3%), ampicillin (1.5%), and kanamycin (1.4%). Resistance to cephalothin, chloramphenicol, gentamicin and trimethoprim occurred in less than 1% of isolates. There was no resistance to norfloxacin. Isolates from human sources were significantly (P less than 0.001) more resistant (10%) than those from other sources (3.2%). The majority of resistant isolates were resistant to more than one antibiotic, but multiresistance to five or more antibiotics occurred only among human isolates. Comparison of these results with data from earlier years shows that there has been little change in the incidence of resistance among salmonella in this country over the last 10 years. The prevalence of antibiotic resistance among salmonella in New Zealand is low relative to many other countries.     

老年病区嗜麦芽寡养单胞菌的耐药性分析

目的 了解临床分离的嗜麦芽寡养单胞菌对常用抗菌药物的耐药性,指导临床合理使用抗菌约物.方法 使用纸片扩散法测定60株嗜麦芽寡养单胞菌对抗菌药物的敏感性.结果 60株嗜麦芽寡养单胞菌中,痰液标本54株,占90.0％,尿液等其他标本6株,占10.0％;嗜麦芽寡养单胞菌对米诺环素的耐药率最低为5.0％、其次为磺胺甲噁唑/甲氧苄啶为6,7％、环丙沙星为26.7％、头孢哌酮/舒巴坦为28.3％,而亚胺培南耐药率为96.7％.结论 嗜麦芽寡养单胞菌对米诺环素、磺胺甲噁唑/甲氧苄啶、环丙沙星较敏感,对其他抗菌药物耐药情况严重,临床应加强细菌耐药性的检测和监测.     

Prevalence and antimicrobial-resistance of Pseudomonas aeruginosa in swimming pools and hot tubs

Pseudomonas aeruginosa is an important opportunistic pathogen in recreational waters and the primary cause of hot tub folliculitis and otitis externa. The aim of this surveillance study was to determine the background prevalence and antimicrobial resistance profile of P. aeruginosa in swimming pools and hot tubs. A convenience sample of 108 samples was obtained from three hot tubs and eight indoor swimming pools. Water and swab samples were processed using membrane filtration, followed by confirmation with polymerase chain reaction. Twenty-three samples (21%) were positive for P. aeruginosa, and 23 isolates underwent susceptibility testing using the microdilution method. Resistance was noted to several antibiotic agents, including amikacin (intermediate), aztreonam, ceftriaxone, gentamicin, imipenem, meropenem (intermediate), ticarcillin/clavulanic acid, tobramycin (intermediate), and trimethoprim/sulfamethoxazole. The results of this surveillance study indicate that 96% of P. aeruginosa isolates tested from swimming pools and hot tubs were multidrug resistant. These results may have important implications for cystic fibrosis patients and other immune-suppressed individuals, for whom infection with multidrug-resistant P. aeruginosa would have greater impact. Our results underlie the importance of rigorous facility maintenance, and provide prevalence data on the occurrence of antimicrobial resistant strains of this important recreational water-associated and nosocomial pathogen.     

Commensal pseudomonas species isolated from wastewater and freshwater milieus in the eastern cape province, South Africa, as reservoir of antibiotic resistant determinants

Pseudomonas species are opportunistic pathogens with implications in a wide range of diseases including cystic fibrosis and sickle cell anaemia. Because of their status as multidrug resistant (MDR) and extremely drug resistant (XDR) bacteria Pseudomonas species represent a threat to public health. Prevalence, antibiogram and associated antibiotic resistant genes of Pseudomonas species isolated from freshwater and mixed liquor environments in the Eastern Cape Province of South Africa were assessed. Polymerase chain reaction (PCR) based technique was used to identify the isolates and screen for antibiotic resistant genes. The result shows occurrence of Pseudomonas spp. in freshwater and mixed liquor as follows: 71.42% and 37.5% (P. putida), 14.28% and 31.25% (P. flourescens), 7.14% and 6.25% (P. aeruginosa) and 7.14% and 25% for other Pseudomonas species respectively. Disk diffusion antibiogram of the Pseudomonas isolates from the two locations showed 100% resistance to penicillin, oxacillin, clindamycin, rifampicin and 100% susceptibility to ciprofloxacin and gentamicin with varied percentage resistances to cephalothin, nalidixic acid, tetracycline, and ampicillin. The bla(TEM) antibiotic resistant gene was detected in 12.5% of P. putida, 57.14% of P. fluorescens, 100% P. aeruginosa and 40% in other Pseudomonas species. Similarly, Integrons conserved segment were detected in 12.5% of P. putida, 57.14% of P. fluorescens, 100% of P. aeruginosa and 40% of other Pseudomonas species. The presence of bla(TEM) gene and integrons conserved segment in some of the isolates is worrisome and suggest Pseudomonas species as important reservoirs of multidrug resistance genes in the Eastern Cape Province environment.     

Molecular characterization and antibiotic resistance profiling of Salmonella isolated from retail Turkey meat products

Contaminated poultry meat has been identified as one of the principal foodborne sources of Salmonella. Molecular characterization of Salmonella is important in addressing methods to control this pathogen. Seventy-four retail turkey meat samples were collected from various stores in Fargo, North Dakota in the fall of 2003. Salmonella was recovered from 30 samples using the standard conventional culture method (FSIS, USDA). Isolated Salmonella were characterized by serotyping, pulsed-field gel electrophoresis (PFGE) analysis, plasmid analysis, and antibiotic resistance profiling. Five serotypes were identified among the isolates: Newport (n = 12), Hadar (n = 8), Heidelberg (n = 7), 4,12:nonmotile (n = 2), and Reading (n = 1). XbaI PFGE analysis revealed 13 PFGE types and succeeded in grouping the isolates according to their serotypes. Plasmid profiling identified 5 plasmid types (with 1 or 2 plasmids) among eleven isolates that harbored plasmids. Seventeen isolates were resistant to antibiotics. The Heidelberg serotype showed resistance to multiple antibiotics: 1 isolate had resistance to gentamicin, sulfamethoxazole, and streptomycin, and 6 isolates had resistance to tetracycline, gentamycin, sulfamethoxazole, kanamycin, and streptomycin. The Hadar serotype isolates were resistant to 2 or 3 antibiotics: tetracycline and streptomycin (1 isolate); tetracycline and kanamycin (1 isolate); and tetracycline, kanamycin, and streptomycin (6 isolates). The 4,12:nonmotile serotype isolates showed resistance to tetracycline only. The Newport and the Reading serotypes were susceptible to all 16 of the antimicrobials tested.     

深圳市健康人群肠道大肠埃希菌耐药性调查

目的：研究深圳市健康人群肠道大肠埃希菌耐药性.方法：按《预防医学微生物学及检验技术》的方法分离健康人肠道大肠埃希菌,K-B法测定细菌对15种抗生素的耐药性.结果：健康人大肠埃希菌对四环素（63.33%）萘啶酸（49.33%）磺胺甲基异[口恶]唑（40.67%）氨苄西林（38.67%）复方新诺明（35.33%）较耐受,对头孢菌素类及头孢美唑和氨曲南很敏感.121株（80.67%）对1种以上抗生素耐药,对两种以上抗生素耐药的菌株为87株（58%）,36株（24%）对5种以上抗生素耐药,有2株对9种抗生素耐药.结论：深圳市健康人群肠道大肠埃希菌耐药性较严重,应严格控制抗生素使用并继续做好耐药性监测工作.     

泌尿系感染病原菌的变迁及耐药性分析

目的了解近年来泌尿系感染病原菌的变迁及耐药现状. 方法应用回顾性调查分析方法,对我院1997至2000年间泌尿系感染检测的1 026株病原菌的分布及耐药性进行统计分析. 结果在泌尿系感染的病原菌中,G+球菌上升,G-杆菌下降,真菌上升,其中粪肠球菌上升和变形菌属下降差异有显著性(P<0.05),药敏实验结果对以往常用的抗菌药物青霉素类、复方新诺明、红霉素、诺氟沙星及一代头孢显示较高的耐药性,2000年耐药率>81.6%,对三代头孢、环丙沙星、庆大霉素呈中度耐药,耐药率在42.9%～78.3%,对阿米卡星及头孢哌酮/舒巴坦呈轻度耐药,耐药率<36.7%. 结论随着抗生素的更新换代、人口老龄化及医院感染等因素的变化,泌尿系感染病原菌的分布及耐药性均发生了变迁.     

陕西部分地区零售肉中沙门菌耐药的检测分析

目的 对陕西省西安市和杨凌示范区超级市场及农贸市场零售肉中沙门菌的药敏性进行检测分析.方法 采用美国临床实验室标准化委员会(National Committee of Clinical Laboratorystandard,NCCLS)推荐的琼脂稀释法,以大肠埃希菌ATCC25922和粪肠球菌ATCC29212为质控菌株,对193株沙门菌进行了7大类共14种抗生素的药敏性检测.结果 沙门菌分离株对磺胺甲嗯唑的抗性最高(44.6%),其次为卡那霉素(40.9%)、四环素(37.8%)、阿莫西林(26.9%)、氨苄西林(25.4%)、庆大霉素(23.3%)和氯霉素(21.8%)等;对氟喹诺酮类抗生素的耐药率依次分别为环丙沙星22.3%、恩诺沙星21.8%、左氧氟沙星20.7%、加替沙星20.2%.55株(28.5%)沙门菌为多重耐药株,其中28株(14.5%)可耐至少13种抗生素,24株(12.4%)的耐药介于4到12种之间.结论 陕西西安地区零售肉沙门菌多重耐药现象比较严重.     

Relationship between rates of antimicrobial consumption and the incidence of antimicrobial resistance in Staphylococcus aureus and Pseudomonas aeruginosa isolates from 47 French hospitals.

OBJECTIVE: To investigate relationships between rates of antimicrobial consumption and the incidence of antimicrobial resistance in Staphylococcus aureus and Pseudomonas aeruginosa isolates from hospitals. METHODS: We conducted an observational study that used retrospective data from 2002 and linear regression to model relationships. Hospitals were asked to collect data on consecutive S. aureus and P. aeruginosa isolates, consumption rates for antibiotics (ie, anti-infectives for systemic use as defined by Anatomical Therapeutic Chemical class J01), and hospital characteristics, including infection control policies. Rates of methicillin resistance in S. aureus and rates of ceftazidime and ciprofloxacin resistance in P. aeruginosa were expressed as the percentage of isolates that were nonsusceptible (ie, either resistant or intermediately susceptible) and as the incidence of nonsuceptible isolates (ie, the number of nonsuceptible isolates recovered per 1,000 patient-days). The rate of antimicrobial consumption was expressed as the number of defined daily doses per 1,000 patient-days. SETTING: Data were obtained from 47 French hospitals, and a total of 12,188 S. aureus isolates and 6,370 P. aeruginosa isolates were tested. RESULTS: In the multivariate analysis, fewer antimicrobials showed a significant association between the consumption rate and the percentage of isolates that were resistant than an association between the consumption rate and the incidence of resistance. The overall rate of antibiotic consumption, not including the antibiotics used to treat methicillin-resistant S. aureus infection, explained 13% of the variance between hospitals in the incidence of methicillin resistance among S. aureus isolates. The incidence of methicillin resistance in S. aureus isolates increased with the use of ciprofloxacin and levofloxacin and with the percentage of the hospital's beds located in intensive care units (adjusted multivariate coefficient of determination [aR(2)], 0.30). For P. aeruginosa, the incidence of ceftazidime resistance was greater in hospitals with higher consumption rates for ceftazidime, levofloxacin, and gentamicin (aR(2), 0.37). The incidence of ciprofloxacin resistance increased with the use of fluoroquinolones and with the percentage of a hospital's beds located in intensive care ( aR(2), 0.28). CONCLUSIONS: A statistically significant relationship existed between the rate of fluoroquinolone use and the rate of antimicrobial resistance among S. aureus and P. aeruginosa isolates. The incidence of resistant isolates showed a stronger association with the rate of antimicrobial use than did the percentage of isolates with resistance.     

Molecular characteristics of Salmonella enterica Paratyphi A in Yunnan Province,southwest China

Previously, the prevalence of Salmonella enterica Paratyphi A in Yunnan was high; and recently Yunnan was the predominant endemic province in China. To identify the molecular epidemiology, antibiotic resistance profile and genotypic diversity of the S. Paratyphi A isolates from 1995 to 2013 in Yunnan, we performed the study. Antibiotic susceptibility tests, pulse-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to identify the characteristics of the bacterial isolates. The results showed from 1995 to 2013, 366 S. Paratyphi A were isolated: 295 isolates (80.6%) from Yuxi and 68 isolates (18.58%) from Honghe. All of the strains were resistant to nalidixic acid, and some were resistant to ampicillin and trimethoprim/sulfamethoxazole in different years. All the isolates were sensitive to cefotaxime and ciprofloxacin. Identical PFGE with two enzyme digestion patterns were found for 339 isolates. Some environmental isolates in different years were homologous with the strains isolated from food and patients. MLST showed 349 strains were ST85, only 17 isolates were ST129. S. Paratyphi A isolates from Yunnan showed a high similarity, and we found the pathogen isolated from patients, the environment and food had the close epidemiological relationship, forming a transmission circulation. These findings have important implications for paratyphoid-control strategies.     

Epidemiological profile and antibiotic susceptibility of Pseudomonas aeruginosa isolates within the burned patient hospitalized in the intensive care burn unit

BACKGROUND: Pseudomonas aeruginosa plays a predominant role as an etiological agent involved in serious infections in burned patients. Treatment of these infections is frequently complicated by antibiotic resistance, a problem that is is increasing in recent years. AIM: The objective of this study is to analyze epidemiological profile and antibiotic susceptibility of P. aeruginosa isolates within the burned patients admitted in our intensive care department. METHODS: During a period of 4 years (2000/2003), 828 burn patients were admitted. RESULTS: The survey of antibiotic susceptibility of P. aeruginosa showed high percentages of resistance to the different antibiotics. 60.9% of strains were resistant to piperacillin, 53.4% to ceftazidime, 37.6% to imipenem, 70.6% to cefsulodine, 59.3% to tobramycin, 80% to gentamicin, 62.4% to amikacin and 53.4% to ciprofloxacin. CONCLUSION: It is necessary to implement urgent measures to prevent the spreading of this multiresistant strain. These measures include: sensible limitation of the use of antimicrobial agent, strict disinfection and hygienic procedures.     

2010年医院细菌耐药性监测

目的 了解医院2010年临床分离菌对各类抗菌药物的耐药性.方法 采用纸片扩散法(K-B法)检测临床分离菌对各类抗菌药物的敏感性.结果 临床分离1541株细菌中革兰阴性菌占73.5％,革兰阳性菌占26.5％,金黄色葡萄球菌和凝固酶阴性葡萄球菌中耐甲氧西林株分别占78.7％和86.2％,其耐药率显著高于甲氧西林敏感株,但仍有61.9％的MRSA对磺胺甲噁唑/甲氧苄啶敏感,87.0％的MRCNS对利福平敏感;肠球菌属中屎肠球菌的检出率为52.1％,首次高于粪肠球菌检出率的25.5％,未发现耐万古霉素、替考拉宁、利奈唑胺葡萄球菌和肠球菌,大肠埃希菌和克雷伯菌属细菌中产ESBLs株检出率分别为53.8％和43.1％,产ESBLs株的耐药率明显高于非产ESBLs株,未发现碳青霉烯类耐药株,不动杆菌属对头孢哌酮/舒巴坦较敏感,对亚胺培南、美罗培南的耐药率分别为52.4％、60.2％;铜绿假单胞菌对两者的耐药率分别为9.6％、9.1％;米诺环素对嗜麦芽寡养单胞菌和洋葱伯克霍尔德菌有良好的抗菌活性,敏感率均＞95.0％;出现7株泛耐药的铜绿单胞菌和5株泛耐药鲍氏不动杆菌.结论 凝固酶阴性葡萄球菌中甲氧西林耐药株的检出率高,不动杆菌属对两种碳青霉烯类药物的耐药率均＞50.0％,并出现部分泛耐药鲍氏不动杆菌和铜绿假单胞菌,应引起重视,及早采取预防控制措施.     

中国市售酸奶乳酸菌的耐药性分析

目的了解中国市售酸奶中常用乳酸菌菌种的耐药性。方法采用琼脂平板稀释法,对14株嗜热链球菌、12株嗜酸乳杆菌、9株保加利亚乳杆菌、8株双歧杆菌共计43株乳酸菌进行了22种抗生素的药敏性检测。结果 43株乳酸菌对甲氧苄啶、萘啶酮酸、环丙沙星、诺氟沙星、达氟沙星及多粘菌素E均耐药;对卡那霉素、四环素、克林霉素多西环素及头孢噻吩表现出不同程度的耐受性;对其他抗生素敏感或中度敏感。多重耐药乳酸菌检出率100.0%。结论市售酸奶中乳酸菌的耐药性已较为严重,应加强其耐药性连续监测及安全评价。     

耐亚胺培南铜绿假单胞菌的感染现状及耐药性分析

目的 探讨医院耐亚胺培南铜绿假单胞菌(PAE)的感染现状及耐药性,为临床医师合理用药提供依据.方法 收集医院2008年1月-2010年12月临床分离的128株耐业胺培南铜绿假单胞菌的感染现状及耐药性进行回顾性分析 结果 耐业胺培南铜绿假单胞菌主要分布在ICU、脑病科、肿瘤科,分别占60.9％、21.9％、8.6％;在各类标本中的检出率以痰液、脓液、创面分泌物较高,分别占 60.2％、12.5％、12.5％;耐亚胺培南铜绿假单胞菌对黏菌素B耐药率最低为0,对头孢他啶、阿米卡星耐药率相对较低,为40.62％、46.09％;耐药率＞80.0％的有磺胺甲噁唑/甲氧芐啶、头孢噻肟、美罗培南、氨曲南、环丙沙星、庆大霉素、左氧氟沙星;耐药率＞ 50.0％的有哌拉西林、头孢哌酮/舒巴坦、哌拉西林/舒巴坦.结论 耐亚胺培南铜绿假单胞菌多药耐药现象极为严重,应加强耐药监测,合理使用抗菌药物,严防耐亚胺培南铜绿假单胞菌的蔓延.     

Minimum inhibitory concentration (MIC) of some antibiotics against Vibrio cholerae O139 isolates from Pondicherry.

The antibiotic susceptibility pattern of Vibrio cholerae O139, Bengal, an emerging intestinal pathogen has been determined by the Kirby Bauer technique and the MIC values of some antibiotics against these strains by agar dilution technique. All the strains were susceptible to tetracycline, norfloxacin, ciprofloxacin and a majority was susceptible to gentamicin (95.7%) and nalidixic acid (82.9%). Only 51% were susceptible to cefotaxime and most strains were resistant to furazolidone (95.7%), ampicillin (87.3%) and co-trimoxazole (91.5%). The study shows the importance of judicious use of antibiotics in cholera cases and the need for monitoring the susceptibility status of these strains particularly because of their ability to cause extra-intestinal infections like septicaemia.     

多重PCR检测铜绿假单胞菌耐药基因

目的了解铜绿假单胞菌耐药现状。方法采用多重PCR方法检测铜绿假单胞菌中的常见耐药基因。结果 39株铜绿假单胞菌耐药基因TEM、AmpC、VIM阳性率分别为84.6%、76.9%、17.9%,OXA基因扩增阴性。铜绿假单胞菌对替卡西林、妥布霉素、环丙沙星、头孢他啶耐药率均大于28.2%（11/39）,耐药率最高为庆大霉素59.0%,对多粘菌素E最敏感92.3%,本组菌株中有25.6%（10/39）表现为多重耐药。结论研究表明,携带TEM、AmpC、VIM是导致本组铜绿假单胞菌耐药的重要机制,β-内酰胺类抗生素耐药性及多重耐药性均较严重。     

Prevalence of carriage of antimicrobial resistant strains of Streptococcus pneumoniae in primary school children in Hong Kong

A cross-sectional survey was conducted to determine prevalence and assess risk factors for carriage of antibiotic resistant strains of Streptococcus pneumoniae in healthy school children in Hong Kong. Throat swabs were collected from 1455 subjects and written questionnaires providing demographic data and medical history were completed by parents. The overall carriage rate of Streptococcus pneumoniae was 3.5%, of which 49% were penicillin resistant. High levels of resistance to tetracycline (73%), erythromycin (52%), trimethoprim (66%) and ciprofloxacin (57%) were observed. Carriage was associated with presence of a younger sibling (OR = 1.79) and use of antibiotics (OR = 2.31). High use of day care and small size of housing units did not result in a high rate of carriage. The low rate of carriage may be linked to high use of antibiotics, geographical factors or ethnicity. High rates of antibiotic resistance reflect heavy use of antibiotics by general practitioners.     

2008—2010年某院临床主要病原菌分布及耐药性变迁

目的探讨某院临床近年主要病原菌分布及耐药性,为临床合理用药提供依据。方法收集该院2008年1月-2010年12月分离自门诊及住院患者的病原菌资料,对其构成及耐药性作统计分析。结果共分离病原菌7 008株,其中革兰阴性菌3 961株（56.52％）,革兰阳性菌1 582株（22.57％）,真菌1 465株（20.91％）;居前3位的病原菌依次为白假丝酵母菌（1 015株,15.00%）、铜绿假单胞菌（906株,12.93%）、大肠埃希菌（874株,12.47%）。2008-2010年,金黄色葡萄球菌中耐甲氧西林株总检出率为85.07％(678/797),凝固酶阴性葡萄球菌中耐甲氧西林株总检出率为73.17％(150/205);大肠埃希菌和肺炎克雷伯菌产超广谱β 内酰胺酶株的总检出率分别为64.19％（561/874）、46.31％（301/650）。金黄色葡萄球菌对万古霉素、替考拉宁敏感,对复方磺胺甲口恶唑敏感率（68.42％～74.51%）较高,对其余抗菌药物敏感率均＜30%;凝固酶阴性葡萄球菌对万古霉素、替考拉宁敏感;大肠埃希菌和肺炎克雷伯菌对亚胺培南和美罗培南敏感率（95.52％～100.00％）最高,大肠埃希菌对第三代头孢菌素头孢噻肟、头孢曲松、头孢哌酮和氟喹诺酮类环丙沙星、左氧氟沙星敏感率均＜30％。3年铜绿假单胞菌对头孢他啶和美罗培南的敏感率均较高,分别为60.31%~85.83%、59.38%~73.23%。结论该院分离的主要病原菌对常用抗菌药物耐药性普遍较高,应加强监控,合理使用抗菌药物,有效预防和控制医院感染的发生。     

Characterization of Pseudomonas aeruginosa strains isolated from burned patients hospitalized in a major burn center in Tehran, Iran

Pseudomonas aeruginosa is an important life-threatening nosocomial pathogen and plays a prominent role in serious infections in burned patients. The current study was undertaken to characterize P. aeruginosa strains isolated from burned patients in Tehran, Iran. The study was conducted in a major burn center in Tehran, Iran in 2007. A total of seventy specimens obtained from different clinical origin with positive culture results for P. aeruginosa were included in the study. Antimicrobial susceptibility test was performed according to the standard CLSI guideline. The relationship between the strains was also determined using antimicrobial drug resistance pattern analysis and plasmid profiling. All strains were multi drug resistant. The percentage of resistance to tested antibiotics was: imipenem 97.5%, amikacin 90%, piperacillin 87.5%, ceftizoxime 72.7%, gentamicin 67.5%, ciprofloxacin 65%, ceftriaxone 60%, and ceftazidime 57.5%. Thirteen resistant phenotypes were recognized, R3 (TET, IPM, AMK, CIP, PIP, GM, CAZ, CRO, CT) was the predominant resistance pattern seen in 27.5% of isolates. Results obtained from E-test showed that 100% of P. aeruginosa strains were resistant to cefoxitin, 97% to cefotetan, 93% to ticarcillin, 89% to ticarcillin/clav, 76% to gentamicin and imipenem, 63% to piperacillin, 49% to tetracycline, and 20% to meropenem. Nine different plasmid profiles were observed among the strains. The current study showed an increase rate of resistance for some antibiotics tested among P. aeruginosa strains isolated from burned patients in Tehran. A combination of antibiotic susceptibility testing and profile plasmid analysis, which are relatively cheap and available methods, showed to be useful to characterize the clinical strains of P. aeruginosa isolated from burned patients in Iran.     

Increasing antibiotic resistance among isolates of Escherichia coli recovered from inpatients and outpatients in a Saudi Arabian hospital.

OBJECTIVE: To study the pattern of antibiotic resistance among Escherichia coli and the trend in resistance during a 6-year period in a Saudi Arabian hospital. DESIGN: Retrospective in vitro surveillance study of the antibiotic susceptibility pattern among E. coli isolates recovered from outpatients and from inpatients. SETTING: A general hospital in Saudi Arabia. PATIENTS: All patients with a culture positive for E. coli during a 6-year study period. RESULTS: A statistically significant increase in antibiotic resistance was observed among outpatient and inpatient isolates of E. coli. Inpatient isolates were more likely to be resistant to antimicrobial agents. Among isolates from outpatients, 50% were resistant to ampicillin, 33% were resistant to trimethoprim-sulfamethoxazole (TMP-SMZ), and 14% were resistant to ciprofloxacin. Among isolates from inpatients, 63% were resistant to ampicillin, 44% were resistant to TMP-SMZ, and 33% were resistant to ciprofloxacin. There was a low rate of resistance to imipenem (0.3% of isolates), amikacin (2%), and nitrofurantoin (2.4%-6.5%). Resistance to ceftazidime was detected in 9% of outpatient isolates and 17% of inpatient isolates. Multidrug resistance was defined as resistance to 2 or more classes of antibiotics. Multidrug resistance was detected in 2.0%-28.1% of outpatient isolates and 7.4%-39.6% of inpatient isolates, depending on the combination of antimicrobials tested. More isolates were resistant to ampicillin plus TMP-SMZ than to any other combination of antimicrobials. CONCLUSION: The prevalence of antibiotic resistance among outpatient and inpatient E. coli isolates increased during the study period. The rates of antibiotic resistance were statistically significantly higher among inpatient isolates, compared with outpatient isolates. These findings call for wiser use of antibiotics and continued surveillance of antibiotic resistance.