Antibiotic resistance of urinary tract pathogens and evaluation of empirical treatment in Turkish children with urinary tract infections

The changing pattern of antimicrobial resistance in the causative microorganisms of urinary tract infection (UTI) in childhood is a growing problem. The aims of this study were to assess the resistance patterns of urinary isolates to commonly used antimicrobials and to evaluate the options for empirical treatment of UTI. A prospective cross-sectional analysis of bacteria isolated from children with UTI was performed between January 2003 and January 2004. Resistance to antibiotics was analysed in three age groups: Group I, < or =12 months; Group II, 13-60 months; and Group III, >60 months. A total of 165 urinary pathogens were isolated from 131 patients. Mean patient age was 63.7+/-49.8 months. The most common causative agent was Escherichia coli (87% of cases) followed by Klebsiella pneumoniae (10%). Resistance to ampicillin (74.2%) and co-trimoxazole (61.3%) was significant in all isolates. Nitrofurantoin was the most active agent against E. coli (2.2% resistant isolates), followed by amikacin (4.9%), ceftriaxone (7.5%) and ciprofloxacin (12%). None of the isolates from Group I patients were resistant to ciprofloxacin and a low resistance rate (7.1%) was noted for amikacin. In Group II patients, none of the isolates were resistant to amikacin, and ceftriaxone was the second most suitable antibiotic (resistance rate 2.2%). In Group III patients, the lowest resistance rate was against nitrofurantoin (2.7%). In conclusion, we observed that the use of ampicillin and co-trimoxazole as a single agent for empirical treatment of a suspected UTI would not cover the majority of urinary pathogens in our region. Whilst amikacin, with a negligible resistance rate, was suitable in all age groups, gentamicin might still be useful as an empirical treatment of UTI in children aged >1 year. Nitrofurantoin could be included as a reasonable alternative in the empirical treatment of lower UTI in older children.     

Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1983). III. Secular changes in susceptibility

The in vitro antimicrobial activities of antibiotics against causative pathogens isolated from patients with urinary tract infections (UTI) in the 8 institutions in Japan during the period from 1980 to 1983 were compared. A number of new beta-lactam antibiotics with broad spectrum of activity have become available for clinical use in recent years. Some of them, in particular so-called third generation cephems, are reported to be responsible for developing microbial-cross resistance to multiple beta-lactam antibiotics. We have been making survey in recent years to explore changes in susceptibility to various antimicrobial agents of clinical isolates. All bacterial isolates from clinical specimens were submitted to the Department of Clinical Pathology, Juntendo University School of Medicine, where they were tested for antimicrobial susceptibility with MIC 2000 apparatus. Of all pathogens from patients with simple UTI, the majority of the isolates was E. coli and Klebsiella spp. In cases of complicated UTI, on the other hand, Pseudomonas spp. were most frequent, followed in order by Proteus spp., Klebsiella spp., Serratia spp., Citrobacter spp. and E. coli. Conspicuous changes in antimicrobial activity of antibiotics against E. coli and Klebsiella spp. from simple UTI have not been found in our survey. Against strains of Citrobacter spp., even the third generation cephems proved to be not remarkably active and there was a significant decrease in susceptibility of isolates to the drugs test-showed MIC values of 50 micrograms/ml and the proportion increased to 50% (22/44) with isolates obtained in 1982. The antimicrobial activity of cefsulodin and gentamicin against P. aeruginosa was decreased in 1982 compared with that in 1980 and 1981. However, resistant strains were slightly more frequent with gentamicin. In 1983, the antimicrobial activity of third generation cephems against Serratia spp. was significantly reduced from that in 1982.     

Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1983). II. Background of patients

We have been collected the causative isolates from patients with urinary tract infections (UTI) from the 8 institutions in Japan during 1980-1983. All strains isolated from UTI and recognized as etiologically responsible in each institution were sent to Bacteriology Laboratory of Juntendo University Hospital, Tokyo and the species of these strains were reidentified. We classified the UTI into 3 categories, simple, complicated without catheter and complicated with catheter. Of all strains isolated as etiologically responsible from cases of simple UTI, 65.3% were E. coli and 9.6%, Klebsiella spp. in 1983: these species accounted for about 75% of all isolates. Most frequently isolated from patients without catheter were E. coli 27.6% in 1983, followed in order by Pseudomonas spp. (20.9%), Gram-positive bacteria (16.7%), Serratia spp. (8.8%), Klebsiella spp. (8.0%) and Proteus spp. (7.1%). In complicated UTI with catheter, Pseudomonas spp. were most frequently isolated (25.6%), followed in order by Gram-positive bacteria (22.9%), Serratia spp. (15.0%), Proteus spp. (12.4%), Enterobacter spp. (6.0%) and Klebsiella spp. (6.0%). A remarkable difference, that is, Gram-positive bacteria, especially S. aureus, showed conspicuous increase of isolation between 1982 and 1983. Furthermore, we discussed the detailed analysis of patient background to clinical bacterial isolates from UTI in respect of patient distribution by sex, types of infections, distributions by age in male and female, interrelations between the species of bacterial isolates and types of infection and antimicrobial chemotherapy.     

Bacterial resistance to antimicrobials in urinary isolates

Escherichia coli accounted for about 80% of organisms in uncomplicated urinary tract infections (UTIs), followed by Staphylococcus spp. especially Staphylococcus saprophyticus, and Proteus mirabilis. Against E. coli isolates from patients with uncomplicated UTI, faropenem was the most effective. Up to 1999, fluoroquinolone-resistant isolates were not observed in patients with uncomplicated UTI, but in 2001 fluoroquinolone-resistant E. coli isolates emerged and accounted for about 8%. Various types of organisms were isolated in patients with complicated UTI. Enterococcus faecalis, E. coli, and Pseudomonas aeruginosa were the three most frequent organisms isolated. These three organisms accounted for 44.6%. Amongst oral agents, faropenem showed the lowest rate of resistance against E. coli followed by cephems. The rates of highly fluoroquinolone-resistant and cefpodoxime-resistant E. coli isolates increased rapidly from 1998 to 2001. Fluoroquinolone-resistant P. aeruginosa isolates accounted for about 40% in 2001. Against this species, amikacin was the most effective antimicrobials among all agents tested. About 17% of Pseudomonas were resistant to carbapenem. Eight milligram per litre of ampicillin inhibited all E. faecalis isolates; about 60% of Enterococcus faecium were resistant to ampicillin. The rates of levofloxacin-resistant isolates of E. faecalis and E. faecium were 38 and 97% respectively. UTIs caused by vancomycin resistant enterococci (VRE) are rare in Japan.     

Urinary tract infection caused by fluoroquinolone- and cephem-resistant Enterobacteriaceae

In 2001, fluoroquinolone-resistant Escherichia coli isolates emerged in Japan in patients with uncomplicated urinary tract infection (UTI), and accounted for ca. 8% of isolates. This is a worldwide occurrence as reported by the ECO.SENS study. The number of fluoroquinolone- and cephem-resistant Enterobacteriaceae isolates from patients with complicated UTI is increasing. Most cephem-resistant isolates of E. coli, Klebsiella pneumoniae and Proteus mirabilis produce extended-spectrum beta-lactamases (ESBLs). The rates of ESBL-producing Enterobacteriaceae differ between countries but there are ESBL producers in urinary Enterobacteriaceae isolates in most countries. More seriously, most nosocomial ESBL producers are also resistant to non-beta-lactams, such as the fluoroquinolones, fosfomycin and co-trimoxazole. This causes serious problems in the chemotherapy of cystitis.     

Asymptomatic bacteriuria in pregnancy: epidemiological, clinical and microbiological approach

Asymptomatic urinary tract infection is a risk factor for fetal and maternal morbidity including development of pyelonephritis, premature labor and impaired intra-uterine development. In this study, 326 pregnant and 100 non-pregnant control women were screened for significant asymptomatic bacteriuria from April 8 to July 25, 1997 to gain insight into the prevalence rate, clinical characteristics of the disease and microbiological assessments of the causative agents. All the subjects were clinically identified to have no signs and symptoms of urinary tract infection (UTI). The age ranges of the study and control groups were between 15-40 years for both groups with mean of 25.1 and 25.3 years, respectively. Bacteriological screening of mid-stream urine (MSU) revealed that 24/326 (7%) and 3/100 (3%) were positive for asymptomatic bacteriuria in the study group and controls, respectively (P < 0.05). Further biochemical species identification showed that Escherichia coli was found in 11/24 (46%) followed by coagulase-negative staphylococci (CNS) in 8/24 (33%) and Citrobacter freundii in 2/24 (8%). Others found in smaller number included Staphylococcus aureus, Enterobacter cloacae and Proteus rettgeri in 1/24 (4%) each. Antimicrobial susceptibility test revealed that 10/11 (91%) of the E. coli isolates were resistant to ampicillin and amoxicillin and 10/11 (91%) of them sensitive to nitrofurantoin.     

Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1982). III. Secular changes in susceptibility

In vitro susceptibilities have been investigated against several species isolated from patients with simple and complicated urinary tract infections (UTI) during 1980-1982. Antimicrobial activities of the third generation cephems against E. coli isolated from patients with complicated UTI were found to decrease slightly in 1982. And those against Klebsiella spp. isolated from patients with simple and complicated UTI were also found to decrease similarly. Against P. mirabilis, all the drugs tested have showed relatively potent activities and slight changes in the susceptibility. The marked decrease of susceptibility against Citrobacter spp. isolated from UTI have been found even in the third generation cephems. Especially, Citrobacter spp. exhibited a greater degree of resistant to CZX and CPZ. Strains of P. aeruginosa were on the whole susceptible to the drugs tested, CFS, GM, TOB and AMK, inhibiting 50-80% of the strains tested at 1.56 micrograms/ml. CTX, CZX and CMX seemed most effective against S. marcescens among the third generation cephems, inhibiting 50-90% of the strains tested at 3.13 micrograms/ml.     

Diclofenac in the management of E. coli urinary tract infections

E. coli is the main agent of uncomplicated urinary tract infections (UTIs) and accounts for more than 85% of recurrent cystitis and at least 35% of recurrent pyelonephritis. Despite the widespread availability of antibiotics, UTIs remain the most common bacterial infection in the human population. It is currently advised that the clinical administration of antibiotics against the pathogenic bacteria should be prohibitted due to the emergence of multidrug resistant (MDR) bacterial strains. Therefore, newer and more effective antimicrobials are in demand to treat such cases. One hundred and thirty six urine samples were collected from UTI patients. E. coli was isolated from 85 samples, out of which 33% were resistant to common antibiotics. The isolates were decreasingly resistant to ampicillin, tobramycin, augmentin, nalidixic acid, cefuroxime, nitrofurantoin, kanamycin, pipemidic acid, chloramphenicol, cefotaxime, cefamendol, ofloxacin, ceftizoxime, norfloxacin and amikacin. The anti-inflammatory drug diclofenac exhibited significant antibacterial activity against common bacterial strains both in vitro and in vivo. The present work was conducted to evaluate the in vitro inhibitory effect of this drug on the clinically isolated strains of E. coli in hospitals. All the isolates were sensitive to diclofenac, with MIC values ranging from 5-50 microg/mL. The MIC90 value of the drug was 25 microg/mL. Therefore, it may be suggested that diclofenac has the capacity to treat UTI caused by E. coli.     

产超广谱β-内酰胺酶大肠埃希菌尿路感染易感因素及耐药分析

目的 探讨产超广谱β-内酰胺酶(ESBLs)大肠埃希菌尿路感染患者的易感因素及其对抗生素的耐药情况.方法 对我院从2003年至2005年治疗的26例尿培养为产ESBLs大肠埃希菌的尿路感染患者进行回顾性分析,并与非产ESBLs组122例进行比较性分析.结果 产ESBLs大肠埃希菌尿路感染患者88.5%先前应用过广谱抗生素、69.2%的患者尿路存在复杂因素、42.3%接受过侵袭性操作;产ESBL5大肠埃希菌株对第2、3代头孢菌素、喹诺酮类耐药率明显高于非产ESBLs组,但对亚胺培南高度敏感.结论 产ESBLs大肠埃希菌耐药性日趋严重,应重视对尿路感染病原菌的ESBLs检测,并根据药敏合理应用抗生素.     

Prevalence of extended-spectrum beta-lactamase-producing Escherichia coli in a tertiary care hospital in Tehran, Iran

The prevalence of extended-spectrum beta-lactamase (ESBL) production by consecutive, non-repeated Escherichia coli isolates from hospitalised patients was determined over the period from July 2005 to November 2006. A total of 201 E. coli were isolated from various clinical specimens, 135 (67.2%) of which were confirmed as ESBL-positive using the combination disk synergy test. By univariate analysis, male sex, intravascular or urinary catheterisation, recent surgery or hospitalisation and isolation of E. coli from wound or respiratory tube specimens were found to be risk factors for acquisition of resistant bacteria (chi(2) test, P<0.05). However, binary logistic multivariate regression analysis confirmed that isolation of E. coli from urine samples of either males in any hospital ward (odd ratio (OR) 7.52, 95% confidence interval (CI) 1.21-47.62; P=0.031) or patients with prior surgery (OR 13.16, 95% CI 1.81-100.00; P=0.011) were significantly associated with ESBL production. Imipenem, amikacin and piperacillin/tazobactam were found to be highly active against ESBL-positive isolates in vitro (100%, 91.1% and 85.2% susceptibility, respectively). They showed co-resistance with other antibiotics such as fluoroquinolones, gentamicin and trimethoprim/sulfamethoxazole. Of the 135 ESBL-positive isolates, 22 (16.3%) appeared to be of the CTX-M type based on a phenotypic determination method.     

磷霉素对泌尿系感染常见致病菌的敏感性分析

目的：分析磷霉素对泌尿系感染患者常见致病菌的敏感性,为临床治疗泌尿系感染提供依据,指导临床合理用药。方法：对2018年医院泌尿系感染患者清洁中段尿标本进行培养,共分离出病原菌724株,对其进行鉴定和药敏试验,并对肠杆科细菌进行产超广谱β-内酰胺酶（ESBLs）检测,采用纸片扩散法测定磷霉素药敏活性,以CLSI 2018版标准判断药敏结果;应用WHONET 5.6软件分析分离病原菌的分布和耐药情况。结果：分离的病原菌以大肠埃希菌为主,共378株（52.2%）,其次肠球菌126株（17.4%）;肺炎克雷伯菌46株（6.4%）;大肠埃希菌、粪肠球菌、屎肠球菌、肺炎克雷伯菌对磷霉素的敏感率分别为94.7%、94.8%、73.5%、89.1%;大肠埃希菌、肺炎克雷伯菌产ESBLs检出率分别为55.0%和56.5%;产ESBLs大肠埃希菌、肺炎克雷伯菌对磷霉素的敏感率分别为93.3%和84.6%。结论：泌尿系感染致病菌以大肠埃希菌、肠球菌为主,磷霉素对泌尿系感染常见致病菌（包括产ESBLs菌株）具有良好的敏感性,可作为治疗泌尿系感染的经验用药。     

2016—2018年北京某三甲医院中段尿培养的病原菌构成与耐药性分析

目的 分析2016年1月—2018年12月北京积水潭医院住院患者中段尿标本病原菌构成及耐药性,为临床合理使用抗菌药物提供依据。方法 采用VITEK 2 compact全自动细菌鉴定药敏仪进行细菌鉴定和药敏分析,应用WHONET 5.6软件进行数据分析。结果 3490株中段尿培养病原菌,其中革兰阴性菌2097株(60.1%),最常见的是大肠埃希菌(32.8%)、肺炎克雷伯菌(5.5%)、铜绿假单胞菌(5.4%)和奇异变形菌(3.4%);革兰阳性菌1323株(37.9%),最常见的是屎肠球菌(12.5%)、粪肠球菌(8.5%)、表皮葡萄球菌株(3.0%)和无乳链球菌(2.0%)。女性患者大肠埃希菌检出率明显高于男性(45.8%对19.9%),但铜绿假单胞菌在男性患者中占比高于女性(7.6%对3.3%)。大肠埃希菌和肺炎克雷伯菌产ESBLs的检出率为56.3%和58.5%;产ESBLs株对头孢菌素、喹诺酮类、四环素、磺胺类抗菌药物敏感率<50.0%;肠杆菌科细菌对碳青霉烯类抗菌药物高度敏感,为88.5%~100.0%。非发酵菌群中铜绿假单胞菌对大部分抗菌药物敏感率>70.0%。革兰阳性菌对万古霉素、替考拉宁和利奈唑胺高度敏感,为89.0%~100.0%。结论 大肠埃希菌和肠球菌是尿路感染主要病原菌,临床可依据病原菌分布特点及药物敏感性进行早期用药。     

2016—2018年北京某三甲医院中段尿培养的病原菌构成与耐药性分析

目的 分析2016年1月—2018年12月北京积水潭医院住院患者中段尿标本病原菌构成及耐药性,为临床合理使用抗菌药物提供依据。方法 采用VITEK 2 compact全自动细菌鉴定药敏仪进行细菌鉴定和药敏分析,应用WHONET 5.6软件进行数据分析。结果 3490株中段尿培养病原菌,其中革兰阴性菌2097株(60.1%),最常见的是大肠埃希菌(32.8%)、肺炎克雷伯菌(5.5%)、铜绿假单胞菌(5.4%)和奇异变形菌(3.4%);革兰阳性菌1323株(37.9%),最常见的是屎肠球菌(12.5%)、粪肠球菌(8.5%)、表皮葡萄球菌株(3.0%)和无乳链球菌(2.0%)。女性患者大肠埃希菌检出率明显高于男性(45.8%对19.9%),但铜绿假单胞菌在男性患者中占比高于女性(7.6%对3.3%)。大肠埃希菌和肺炎克雷伯菌产ESBLs的检出率为56.3%和58.5%;产ESBLs株对头孢菌素、喹诺酮类、四环素、磺胺类抗菌药物敏感率<50.0%;肠杆菌科细菌对碳青霉烯类抗菌药物高度敏感,为88.5%~100.0%。非发酵菌群中铜绿假单胞菌对大部分抗菌药物敏感率>70.0%。革兰阳性菌对万古霉素、替考拉宁和利奈唑胺高度敏感,为89.0%~100.0%。结论     

尿路感染病原菌及其耐药性分析

目的探讨尿路感染的病原菌及其耐药性变化趋势。方法收集2004年6月至2007年12月清洁中段尿培养分离的病原菌并作细菌药敏及其耐药性分析。结果共收集致病菌467株，革兰阴性杆菌348株，占74．52％；革兰阳性菌69株，占14．78％；真菌50株，占10．71％。革兰阴性杆菌以大肠埃希菌为主（50．01％），革兰阳性菌以肠球菌和凝固酶阴性葡萄球菌为主，真菌以白色假丝酵母菌为主。3年间主要病原菌对常用抗菌药物的耐药率呈上升趋势。结论我院尿路感染的病原菌仍以大肠埃希菌为主，但多重耐药菌的分离率呈上升趋势。     

Nationwide survey of antibacterial activity against clinical isolates from urinary tract infections in Japan (2008)

In this study, the causative bacteria and their sensitivity to various antimicrobial agents as well as risk factors for quinolone-resistant Escherichia coli were investigated in patients with acute uncomplicated cystitis or complicated cystitis by isolation and culture of bacteria from urine samples. In total, 1312 strains were isolated from 1009 patients with acute uncomplicated cystitis, including E. coli (63.3%), Enterococcus faecalis (12.8%) and Streptococcus agalactiae (4.6%). In addition, 994 strains were isolated from 725 patients with complicated cystitis, including E. coli (36.4%), E. faecalis (19.2%), Klebsiella pneumoniae (5.0%), S. agalactiae (4.7%) and Pseudomonas aeruginosa (4.5%). At least 90% of E. coli isolates from acute uncomplicated cystitis showed sensitivity to fluoroquinolones and cephems, whilst 70.4-88.4% of E. coli isolates from complicated cystitis were sensitive to fluoroquinolones and 85.4-89.5% were sensitive to cephems. Factors associated with quinolone-resistant E. coli included two or more episodes of cystitis within 1 year, failure of quinolone therapy, underlying urinary tract disease, prior quinolone treatment within 1 month and age ≥ 75 years. It is important to confirm the sensitivity of causative bacteria for optimal antimicrobial therapy, and empirical antimicrobial agents should be selected by considering patient characteristics and other factors.     

Etiology and susceptibility of urinary tract isolates in Kosova

Urinary tract infections are amongst the most common pathogenic infections with an increasing resistance to antimicrobials. The objective of this study was to determine the etiology and antimicrobial susceptibility patterns of urinary tract infection pathogens isolated in Kosovo. A retrospective study was carried from urine samples of both inpatients and outpatients that were received in our laboratory throughout 2001. During the study period, 16500 urine samples were analysed, of which 4260 (25.8%) had significant bacteriuria obtained from 1420 patients. Of this, 1059 (74.6%) were collected from females and 361 (25.4%) from males. Urine samples processed from outpatients were 72.5% (1029), whereas 27.5% (391) were from hospitalised patients. Escherichia coli was the most common aetiologic agent isolated (80.5%), followed by Proteus spp. (6.1%), Klebsiella spp. (5.9%), Citrobacter (5.1%) and Mycobacterium tuberculosis (0.8%). Gram-positive bacteria accounted for only 0.3%. Pseudomonas aeruginosa was only isolated from inpatients and was responsible for 0.6% of infections. Amoxicillin, ampicillin and trimethoprim-sulphamethoxazole resistance rates were 48.7, 46.5 and 32.1%, respectively. Nitrofurantoin, cefalexin and ciprofloxacin expressed the highest susceptibility among these isolates. E. coli isolates from inpatients and outpatients showed more than 25% resistance to trimethoprim-sulphamethoxazole. Of all isolates, 16% (225) were resistant to three or more agents and considered multi-drug resistant. Current data on the prevalence of multidrug resistance among urinary tract isolates should be a consideration to change the current empiric treatment of urinary tract infections.     

Prevalence of antimicrobial resistance among urinary tract pathogens isolated from female outpatients across the US in 1999

In the United States, trimethoprim-sulphamethoxazole (TMP-SMX) is the recommended first-line treatment for uncomplicated urinary tract infections (UTIs) in females, in regions with resistance rates of <10-20%. Unfortunately, current data on regional resistance is often not readily available to physicians and regional variability in resistance remains largely unknown. This report presents antimicrobial susceptibility data for TMP-SMX and three other commonly tested antimicrobials organized by state and region to demonstrate current regional variability in resistance in the US. In the last quarter of 1999, 5739 fresh clinical isolates of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Staphylococcus saprophyticus were collected from 202 laboratories throughout the US. Susceptibility testing was performed against TMP-SMX, cephalothin, nitrofurantoin and ciprofloxacin using broth microdilution. Data were analyzed by patient age and specimen source, and by state and region. In the US as a whole, resistance to TMP-SMX was 16.8% for E. coli, 7.8% for K. pneumoniae, 12.1% for P. mirabilis and 3.0% for S. saprophyticus, but these rates showed considerable regional variation. By state, E. coli resistance ranged from 7.4% in Pennsylvania to 33.3% in Iowa (among states with > or =50 isolates tested). Regionally, resistance for all uropathogens taken together ranged from 8.5% in East South-Central to 22.8% in West South-Central. Ciprofloxacin demonstrated the broadest activity of the antimicrobials tested and was more active than TMP-SMX against all pathogens. Resistance to TMP-SMX among E. coli now approaches or exceeds 20% in some areas. As resistance among uropathogens reaches clinically significant levels in many areas, continued regional surveillance is essential to ensure the provision of effective empiric therapy for urinary tract infections.     

Susceptibility testing of urinary isolates of Escherichia coli to mecillinam using NCCLS methodology

Criteria for susceptibility testing of mecillinam against 533 isolates of Escherichia coli and a further 309 Enterobacteriaceae, according to NCCLS methodology, were determined. Correlation of MIC to inhibition zones was good for all species. For urinary isolates of E. coli, the following agar dilution breakpoints and corresponding interpretive zone diameters seem appropriate: < or = 8 mg/L/> or = 15 mm for susceptible; 16 mg/L/12-14 mm for intermediate susceptible and > or = 32 mg/L/< or = 11 mm for resistant. The appearance of isolated colonies within the inhibition zone was sometimes noted with disc diffusion, particularly for non-E. coli Enterobacteriaceae. The relevance of these colonies to clinical (bacteriological) efficacy was determined and the results suggested that they could be ignored when testing urinary E. coli.     

Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1984). III. Secular changes in susceptibility

Cases with infections of urinary tracts were divided into 3 groups of the simple infections, and complicated infections without indwelling of catheter, and complicated infections with indwelling of catheter. Susceptibilities to antimicrobial agents of Escherichia coli, Klebsiella spp., Proteus spp., Citrobacter spp., Enterobacter spp., Pseudomonas aeruginosa and Serratia marcescens which were isolated from patients with these infections were determined. There was no tendency of decline in the susceptibilities of E. coli isolated from the patients with simple urinary tract infections (UTI). Susceptibilities of E. coli isolated from the patients with complicated UTI without and with indwelling of catheter to cephem antibiotics of the third generation were examined. The susceptibility of E. coli strains isolated from patients with complicated UTI without and with indwelling of catheter remained the same. More specifically, cefmenoxime (CMX) at a concentration of less than 0.10 microgram/ml inhibited the growth of E. coli isolated from cases without: with catheter at 74.1%: 78.3% in 1982, 75.4%: 73.3% in 1983, and 81.3%: 84.8% in 1984. Also, ceftizoxime (CZX) at a concentration of less than 0.10 microgram/ml inhibited the growth at 83.3%: 95.7% in 1982, 89.2%: 86.7% in 1983, and 91.7%: 97.0% in 1984. Latamoxef (LMOX) at less than 0.10 microgram/ml inhibited the growth at 59.3%: 43.5% in 1982, 47.7%: 40.0% in 1983, and 47.9%: 42.4% in 1984. The antibacterial effect of penicillin against Klebsiella spp. was found to be poor, while those of oral cephem antibiotics, cephalexin (CEX), cefaclor (CCL), and cefazolin (CEZ) which is the cephem antibiotics of the so-called first generation and cefotiam (CTM) among other cephem antibiotics of the so-called second generation were relatively good. A study of susceptibilities of Klebsiella spp. isolated from patients with complicated UTI without and with indwelling of catheter revealed inhibition of growth by CTM at a concentration of 0.39 microgram/ml at 84.0%: 75.9% in 1982, 70.6%: 75.0% in 1983, and 95.8%: 77.8% in 1984. Cefmetazole (CMZ) at a concentration of 0.39 microgram/ml showed a relatively lower rate of growth inhibition of Klebsiella spp., while at 0.78 microgram/ml it inhibited the growth at 88.0%: 72.4% in 1982, 52.9%: 50.0% in 1983, and 70.8%: 66.7% in 1984. The antibacterial effects of both CTM and CMZ against Klebsiella spp. isolated from patients with indwelling of catheter were found to be poor, and some of the bacterial strains showed a MIC over than 100 micrograms/ml.(ABSTRACT TRUNCATED AT 400 WORDS)