Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Research Group for Testing Imipenem Susceptibility on Clinical Isolates

We investigated susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antimicrobial agents at 459 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were performed at each hospital laboratory and the tests were carried out according to the 1-dilution or 3-dilution disc technique in which susceptibilities are classified into 4 grades: , ++, + and -. IPM had significantly high activity against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Neisseria gonorrhoeae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Acinetobacter calcoaceticus, Moraxella catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. and should slightly lower activities on coagulase-negative staphylococci (CNS), Enterococcus faecalis, Haemophilus influenzae, Serratia marcescens, Proteus vulgaris, Providencia stuartii and Pseudomonas aeruginosa than on the above mentioned bacteria. In a comparative study on activities of IPM against bacteria from different clinical sources, no remarkable differences were found due to different sources among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, P. mirabilis or A. calcoaceticus, whereas slight differences were found among Staphylococcus aureus, CNS, S. marcescens and P. aeruginosa.     

The antimicrobial activity of sisomicin against fresh clinical isolates

Antimicrobial activities of sisomicin (SISO) against clinical isolates obtained in the second half of 1986 were investigated together with other 4 aminoglycosides (AGs) (gentamicin (GM), tobramycin (TOB), dibekacin (DKB), amikacin (AMK] and 2 cephems (cefotiam, cefotaxime), and were compared to the results reported in the period of late 1970's through early 1980's in Japan. 1. The incidence of SISO-resistant Staphylococcus aureus in the present study was 18% and is comparable to that of the other studies suggesting that the incidence of SISO resistant strains remains on the stable level. The incidence of SISO-resistant Pseudomonas aeruginosa showed the tendency of slight increase. 2. SISO-resistant strains of Enterobacter spp., Serratia marcescens and Citrobacter freundii did not show increase from the 1970/1980 levels. 3. Isolation rates of SISO-resistant indole(+) Proteus varied depending on strains. Isolation rates of SISO-resistant P. vulgaris and Morganella morganii were both as low as 4%, but that of Providencia rettgeri was as high as 60%. Refering to an American study reporting that the Genus Providencia including P. rettgeri showed high incidence of resistance to SISO as well as to GM or TOB, we pointed out that the antimicrobial activity of AGs against Genus Providencia should be evaluated separately from those of other indole(+) Proteus strains. 4. No SISO-resistant strains of Escherichia coli, Klebsiella pneumoniae or P. mirabilis were found. 5. SISO had good antimicrobial activity against most of the investigated species and SISO may still be regarded as one of the clinically useful AGs.     

Antibacterial activity of gentamicin against clinical isolates in pediatrics

Antibacterial activity of gentamicin (GM), along with activities of other aminoglycosides and beta-lactams, was studied against clinical isolates collected from pediatric patients during a period of May 1986-April 1987. 1. GM-resistance was noted in 22% of Staphylococcus aureus, 6% of Proteus vulgaris, 8% of Morganella morganii, 40% of Providencia spp., 6% of Enterobacter spp., 14% of Serratia marcescens, and 14% of Pseudomonas aeruginosa isolates. No GM-resistance was observed with isolates of Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. 2. The antibacterial activity of GM against clinical isolates from pediatric patients was found to be comparable to its activity against clinical isolates from adults studied at the same time. 3. The majority of GM-resistant strains of S. aureus were MCRSA, and the GM-resistant strains of S. marcescens and P. aeruginosa were found also to be resistant to multiple drugs. 4. GM-resistant strains were found at relatively high rates (14-22%) in S. aureus, S. marcescens and P. aeruginosa. These rates did not increase compared to the rates observed in the first half of the 1980's. 5. GM was considered to have poor antibacterial activity against genus Providencia. It is concluded from above results that GM still maintains effective antibacterial activity against many of causative organisms of infections in both adults and children.     

Antibacterial activities of sisomicin against fresh clinical isolates]

To investigate antibacterial activities of sisomicin (SISO), MICs of SISO as well as other aminoglycosides (AGs) were determined against many clinical isolates which were obtained in 1991. Results are summarized below: 1. No SISO-resistant strains were observed among isolates of Escherichia coli, Citrobacter diversus, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Proteus mirabilis and Morganella morganii. 2. In comparison with the results of our previous study against isolates obtained in 1986, the rate of methicillin-resistant Staphylococcus aureus (MRSA) was higher, and SISO-resistant strains were observed at a high rate among the MRSA. Also, SISO-resistant strains of Serratia marcescens increased. However, the rate of SISO-resistant strains of Pseudomonas aeruginosa decreased, and among Citrobacter freundii, Enterobacter cloacae and Proteus vulgaris, SISO-resistant strains did not increase over the years. 3. MICs of SISO against Providencia rettgeri and Providencia stuartii were high, suggesting that antibacterial activities of SISO was weak against genus Providencia. 4. For comparison, according to MICs of ofloxacin and imipenem, new quinolone-resistant strains were observed at a high rate among various organisms, and carbapenem-resistant strains were observed at a high rate among S. marcescens and P. aeruginosa. 5. SISO is still one of the useful AGs in the 1990's since it maintains its strong antibacterial activities against most clinical isolates obtained in recent years and its potential as a combination drug with beta-lactams is being reported.     

Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Reported by the Research Group for Testing Imipenem Susceptibility on Clinical Isolates

This study was conducted to investigate susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antibacterial agents at 64 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were carried out at each laboratory and the tests were performed according to the disk dilution method recommended by NCCLS in which susceptibilities are classified into "S", "MS", "I" and "R". IPM showed markedly high in vitro activities against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Enterococcus faecalis, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, Providencia stuartii, Acinetobacter calcoaceticus, Moraxella (Branhamella) catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. IPM also had strong activities against Achromobacter xylosoxidans and Pseudomonas aeruginosa, but less active against Flavobacterium spp., E. faecium, coagulase-negative staphylococci (CNS), Staphylococcus aureus and Pseudomonas cepacia. In a study in which activities of IPM against bacteria isolated from different clinical sources were compared, differences in susceptibilities were observed among S. aureus, CNS, A. calcoaceticus and P. aeruginosa, but such differences were not apparent among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, S. marcescens or P. mirabilis.     

Susceptibility of clinical bacterial isolates to aztreonam

In vitro activities of 7 antimicrobial agents against organisms (474 strains) isolated from patients with various infections in Ehime University Hospital from May to July 1986 were investigated. Summarized results are as follows: 1. Aztreonam (AZT) showed potent activities against Escherichia coli, Citrobacter sp., Klebsiella pneumoniae, Serratia marcescens, Proteus sp., Pseudomonas aeruginosa and Haemophilus influenzae. 2. Antimicrobial activities of AZT were especially superior against Proteus sp. to the third generation cephem antibiotics. 3. Enterobacter sp. seemed more susceptible to AZT than to cephem antibiotics, but minimum inhibitory concentrations of AZT against may isolates of Enterobacter sp. were in wide ranges.     

Antimicrobial activity of sulbactam/cefoperazone. Comparison with other new cephems

Antimicrobial activities of sulbactam/cefoperazone (SBT/CPZ) against 50 fresh clinical isolates of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were compared to those of CPZ, Cefotiam (CTM), Cefotaxime (CTX) and Latamoxef (LMOX). Minimal inhibitory concentrations (MIC's) of SBT and CPZ mixed in a ratio of 1:1 were determined by the dilution method using Mueller-Hinton agar and expressed by absolute concentrations of CPZ. Antimicrobial activities of SBT/CPZ against principally penicillinase (PCase) producing bacteria, i.e., S. aureus, E. coli, K. pneumoniae, P. mirabilis, were superior to those of CPZ alone. The presence of SBT in concentrations around 0.39 approximately 1.56 micrograms/ml clearly enhanced CPZ's antimicrobial activities against these PCase producing strains. The synergistic antimicrobial effects of SBT in combination with CPZ were less pronounced against principally cephalosporinase (CEPase) producing bacteria, i.e., C. freundii, Enterobacter spp., S. marcescens, P. vulgaris, and P. aeruginosa, and exerted with SBT at concentrations around 3.13 approximately 12.5 micrograms/ml. Comparative antimicrobial activities indicated by MIC80's of tested agents showed that SBT/CPZ had more stable activities against bacteria ranging from Gram-positive to Gram-negative bacteria than CTM, CTX and LMOX. MIC's of SBT/CPZ were higher than 25 micrograms/ml against 8% of S. aureus, 18% of C. freundii, 10% of Enterobacter spp., 26% of S. marcescens, 2% of P. vulgaris, and 18% of P. aeruginosa. These resistant strains against which the addition of SBT showed no synergism, may possess other mechanism of resistance than beta-lactamase production. It is concluded that the presence of CPZ resistant strains is an actual current problem and not an imaginary future problem, and that the number of resistant strains against other new cephems which have different chemical structure from CPZ is increasing. When these present bacteriological environments are considered, the appearance of SBT/CPZ in the clinical practice is timely and meaningful.     

Susceptibility of clinical isolates from primary care clinics to oral antibacterial agents

The antimicrobial susceptibility of clinical isolates from specimens of patients in primary care clinics in 2005 was investigated by determining the minimum inhibitory concentrations of oral antibacterial agents. The numbers of test strains were 550 for Gram-positive aerobes, 700 for Gram-negative aerobes, and 150 for anaerobes. Cefcapene (CFPN), cefditoren (CDTR), and cefteram (CFTM) showed the most potent activities against Staphylococcus spp. and Streptococcus spp. among the cephems tested and moxifloxacin (MFLX) and tosufloxacin among the new quinolones. Although the new quinolones generally showed potent activities against these species, resistant strains were frequently detected in methicillin-resistant Staphylococcus aureus. In addition, 70% or more of Streptococcus pneumoniae isolates were intermediate or resistant to macrolides. Cephems showed good activities against aerobic Gram-negative bacteria except for Proteus spp. Specifically, CFPN, CDTR, and CFTM showed the most potent activity against Haemophilus influenzae among the cephems tested. The new quinolones showed potent activities against Gram-negative bacteria, especially H. influenzae and Moraxella catarrhalis, but not against Proteus mirabilis and Providencia spp. When compared with the susceptibilities of clinical isolates from tertiary care hospitals, found in other research, differences were noted, for example, there was a lower frequency of quinolone-resistant strains of methicillin-susceptible S. aureus but a higher frequency of macrolide-resistant strains of Streptococcus pyogenes. Therefore, to accurately grasp susceptibility trends, well-focused surveillance studies are necessary.     

Antimicrobial activities of gentamicin against fresh clinical isolates

Antimicrobial activities of gentamicin (GM), compared with activities of other aminoglycosides (AGs) and beta-lactam antibiotics, were studied against clinical isolates obtained during a period of July-December 1989. 1. GM-resistant strains were noted in 24% of Staphylococcus aureus, 12% of Enterobacter spp., 24% of Serratia marcescens, 7% of Morganella morganii and 26% of Pseudomonas aeruginosa, but no GM-resistant strains were observed among isolates of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Proteus vulgaris. 2. A majority of GM-resistant strains of S. aureus were methicillin-resistant S. aureus (MRSA) and a large number of GM-resistant strains of Enterobacter spp. was also resistant to new quinolones. GM showed, however, strong antimicrobial activities against new quinolones-resistant strains of S. marcescens, M. morganii and P. aeruginosa. 3. Among all the isolates tested of S. marcescens, 24% were GM-resistant, 72% were tobramycin (TOB)-resistant, 86% were dibekacin (DKB)-resistant and 64% were amikacin (AMK)-resistant, hence the incidence of GM-resistant strains was the lowest. This tendency was also observed with P. vulgaris. However, among P. aeruginosa, 26% were GM-resistant, 14% TOB-resistant, 18% DKB-resistant and 22% AMK-resistant, thus the incidence rate for GM-resistance was somewhat higher. These results suggest that different AGs-modification enzymes were produced by various clinical isolates under the present condition. 4. Comparing the ratio of GM-resistant strains in the present study with those in 1980 and 1983, the ratio increased among S. aureus, while decreases were observed among Enterobacter spp., S. marcescens, P. vulgaris and P. aeruginosa, indicating that a unilateral tendency of increases in GM-resistant strains did not exist among clinical isolates over the years.     

2002年临床常见革兰氏阴性杆菌耐药性监测

目的　调查国家细菌耐药性监测网临床常见革兰氏阴性杆菌对各种抗菌药物的耐药性现状。方法　药物敏感性试验采用纸片扩散法 ,耐药性数据分析采用 WHONET5软件。结果　 2 0 0 2年国家细菌耐药性监测网 8个省、市、自治区的 5 7家三级甲等医院共收集患者首次分离株 2 4 82 6株 ;大肠埃希氏菌、铜绿假单胞菌和肺炎克雷伯氏菌是最常见菌。主要标本为痰、尿和伤口及分泌物 ,分别占全部标本的 4 7.9% ,16 .8%和 10 .4 %。绝大多数肠杆菌科细菌对亚胺培南和美罗培南敏感 ,其次为第三代头孢菌素、含酶抑制剂的头孢菌素及阿米卡星。 15 % (15 .6 %～ 5 1.2 % )的肠杆菌、柠檬酸杆菌、沙雷氏菌和普罗威登氏菌对第三代头孢菌素耐药。除大肠埃希氏菌外 ,环丙沙星和左氧氟沙星对其他肠杆菌科细菌的耐药率低于 30 % (6 .0 %～ 2 9.7% ) ;产超广谱β-内酰胺酶 (ESBL s)的大肠埃希氏菌和肺炎克雷伯氏菌株的检出率分别为 18.2 %和 2 2 .6 % ;铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为 19.1%和 15 .2 %。鲍氏不动杆菌对碳青霉烯类抗生素较敏感 ,但对头孢哌酮、头孢他啶和阿米卡星的耐药率分别为 5 2 .8% ,4 1.6 %和 31.8%。结论　细菌耐药性问题是抗感染治疗的主要威胁 ,合理使用抗菌药物以降低耐药性和采取有效措     

Prulifloxacin

Prulifloxacin, the prodrug of ulifloxacin, is a broad-spectrum oral fluoroquinolone antibacterial agent. After absorption, prulifloxacin is metabolised by esterases to ulifloxacin. The drug has a long elimination half-life, allowing once-daily administration. Ulifloxacin is generally more active in vitro than other fluoroquinolones against a variety of clinical isolates of Gram-negative bacteria, including community and nosocomial isolates of Escherichia coli, Klebsiella spp., Proteus, Providencia and Morganella spp., Moraxella catarrhalis and Haemophilus spp. The activity of ulifloxacin against Pseudomonas aeruginosa varies between countries. Gram-positive organisms, including meticillin- or oxacillin-susceptible Staphylococcus aureus, Enterococcus spp. and Italian community isolates of Streptococcus pneumoniae are susceptible to ulifloxacin. Activity against Spanish strains of S. pneumoniae is moderate. In well designed clinical trials, good clinical and bacteriological efficacy (similar to that of ciprofloxacin, amoxicillin/clavulanic acid or pefloxacin) was seen with prulifloxacin 600 mg once daily for 10 days in patients with acute exacerbations of chronic bronchitis or complicated lower urinary tract infections (UTIs), and with single-dose prulifloxacin 600 mg in acute, uncomplicated lower UTIs. Prulifloxacin was generally well tolerated in clinical trials, with a similar tolerability profile to that of ciprofloxacin.     

Antibacterial activity of gatifloxacin against various fresh clinical isolates in 2002

Antibacterial activities of gatifloxacin (GFLX) and other antibacterial drugs against various fresh clinical strains (800 isolates) isolated from specimens of patients in 2002 were compared. GFLX was more active than levofloxacin and ciprofloxacin against Gram-positive bacteria such as methicillin susceptible Staphylococcus aureus and Streptococcus pneumoniae. For these isolates, clarithromycin and azithromycin were less active (MIC90; > 16- > 64 micrograms/mL), GFLX was more active than cefdinir. For Escherichia coli, Klebsiella pneumoniae, Acinetobacter species, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis, three quinolones including GFLX were potently active (MIC90; < or = 0.06-0.5 microgram/mL). Pseudomonas aeruginosa isolated from urinary tract infections were resistant to three quinolones including GFLX (MIC90; 32-64 micrograms/mL), however P. aeruginosa isolated from respiratory and otolaryngological infections were more susceptible (MIC90; 0.5-2 micrograms/mL). Quinolones were less active against Neisseria gonorrhoeae as compared with the cephem antibiotics tested, but GFLX was the most active against N. gonorrhoeae among the quinolones tested. In this study, we investigated activity of GFLX against fresh clinical strains isolated early in 2002, GFLX is widely and potently active against S. aureus, S. pneumoniae and various Gram-negative bacteria.     

Comparative in vitro activity of LY 127935 (6059-S), seven cephalosporins, three aminoglycosides, carbenicillin, and ticarcillin

LY 127935 (6059-S), a new semi-synthetic beta-lactam antibiotic was tested simultaneously with 6 cephalosporins, 3 aminoglycosides, carbenicillin and ticarcillin against 398 clinical isolates of Gram-negative bacilli and Gram-positive cocci. Many of the organisms were selected for study because of known resistance to one or more of the clinically available antibiotics tested. Escherichia coli, Klebsiella, Serratia and Providencia were susceptible to LY 127935. Some resistant strains of Enterobacter, Proteus, Pseudomonas aeruginosa and Acinetobacter were also resistant to LY 127935, but many of the strains resistant to other antibiotics were susceptible to LY 127935. The activity of LY 127935 against Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus viridans and Streptococcus bovis was similar to that of cephalexin and cephradine. LY 127935 was not active against methicillin-resistant S. aureus nor enterococcus.     

Survey of the sensitivities of clinical isolates to antibacterial agents (annual report)]

Research groups were formed in 21 institutions nationwide to investigate carbapenem resistance. The activities of various antibacterial agents, principally carbapenems, were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of 17 antibacterial agents for 1,241 strains of 11 bacterial species isolated at all institutions between October and December 1996. The results were as follows: Carbapenems exhibited strong antibacterial activities against MSSA and Streptococcus pneumoniae and showed low activities against MRSA. Their activities against Enterococcus faecalis were comparable to that of ampicillin and piperacillin. The carbapenems showed high activities against Haemophilis influenzae, Escherichia coli, Klebsiella pneumoniae. Enterobacter cloacae. Serratia marcescens and Bacteroides fragilis group. Their activities were greater than that exhibited by other beta-lactam antibacterial agents, but some resistant strains of Serratia marcescens were detected. The antibacterial activity of carbapenems against Pseudomonas aeruginosa was comparable to that of CAZ, and there were some resistant strains.     

Antibacterial activities of monobactams against fresh clinical isolates

Antibacterial activities of monobactam antibiotics (carumonam (CRMN) and aztreonam (AZT] against Gram-negative bacilli isolated from inpatients in the latter half of 1987 were investigated using penicillin (PC: piperacillin (PIPC], cephems (CEPs: ceftazidime (CAZ), cefotaxime (CTX), latamoxef (LMOX), cefsulodin (CFS], carbapenem (imipenem (IPM] and pyridonecarboxylic acids (norfloxacin (NFLX) and ofloxacin (OFLX] as reference antibiotics. A total of 400 strains of 13 species, i.e. Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Pseudomonas aeruginosa and Haemophilus influenzae, were used as test strains. 1. CRMN and AZT, both monobactam antibiotics, were roughly comparable in their activities and no resistant strain to these antibiotics were found among isolates of E. coli, Klebsiella spp., Proteus spp., M. morganii, P. rettgeri or H. influenzae and few resistant strains were observed among isolates of S. marcescens. On the other hand, isolates of C. freundii, Enterobacter spp. and P. aeruginosa included rather numerous strains resistant to the monobactam antibiotics. Among these cases, whereas R strains, i.e. resistant strains showing MICs greater than or equal to 50 micrograms/ml, accounted for a large proportion of strains resistant to PC and CEPs, I strains, i.e. intermediately resistant strains showing MICs between 12.5 and 25 micrograms/ml, accounted for a large proportion of strains resistant to the monobactam antibiotics. 2. Strains resistant to PIPC, a PC, were detected with high and more or less uniform frequencies over the entire spectrum of the isolates examined. 3. Antibacterial activities of CEPs varied against different bacterial species. While strains resistant to CTX, CAZ and LMOX were commonly detected with high frequencies among isolates of C. freundii, Enterobacter spp. and S. marcescens, large percentages of LMOX-resistant strains of C. freundii and Enterobacter spp. were of the I type. CTX-resistant strains were also found among isolates of P. vulgaris and M. morganii. Proportions of CEP-resistant strains of P. aeruginosa were 28% for CFS and 12% for CAZ. 4. No or few strains among the isolates of 13 species investigated were resistant to IPM, a carbapenem antibiotic, which showed the most stable antibacterial activity, but it was less active than monobactam antibiotics and CEPs against Klebsiella spp., P. mirabilis and H. influenzae.(ABSTRACT TRUNCATED AT 400 WORDS)     

2016年齐齐哈尔市第一医院细菌耐药性分析

目的 了解2016年齐齐哈尔市第一医院临床分离菌对常见抗菌药物的敏感性和耐药性,为临床合理使用抗菌药物提供实验室依据。方法 采用自动化仪器对2016年1月1日-12月31日齐齐哈尔市第一医院临床分离菌进行药敏试验,采用美国临床实验室标准化研究协会(CLSI)2014年版标准判断药敏结果及WHONET 5.6软件进行数据分析。结果 2016年共收集非重复临床分离菌3,505株,其中革兰阴性菌2,450株,占69.9%;革兰阳性菌1,055株,占30.1%。取自下呼吸道标本所占比率最高57.3%,其次为尿液10.5%和血液10.3%。排在前5位的细菌依次为大肠埃希菌、肺炎克雷伯菌、金黄色葡萄球菌、铜绿假单胞菌和鲍曼不动杆菌,分别占18.43%、15.92%、14.41%、13.92%和7.93%。耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(methicillin-resistant coagulase-negative Staphylococci,MRCNS)的检出率分别为27.4%和74.2%。未发现对万古霉素和利奈唑胺的葡萄球菌。肠球菌属细菌中粪肠球菌对所测试的抗菌药的耐药率显著低于屎肠球菌,未发现耐万古霉素和利奈唑胺的肠球菌。大肠埃希菌、克雷伯菌属细菌(肺炎克雷伯菌、产酸克雷伯菌)和奇异变形菌的ESBLs,检出率分别为43.3%、20.1%和18.4%。肠杆菌科细菌对碳青霉烯类抗生素高度敏感,但是仍有对少数碳青霉烯类耐药肠杆菌科细菌(carbapenem resistant Enterobacteriaceae,CRE),以肺炎克雷伯菌居多。对碳青霉烯类抗生素耐药的铜绿假单胞菌和不动杆菌属检出率分别为17.5%和60.4%。肺炎链球菌对红霉素和克林霉素耐药率大于98%,青霉素耐药的肺炎链球菌(PRSP)占2.3%。结论 细菌耐药性仍对临床构成严重威胁,应重视细菌耐药性监测并加强抗菌药物的合理使用。     

In vitro study of the antibacterial activity of ofloxacin against recent clinical isolates

The in vitro activity of ofloxacin, a new broad-spectrum antimicrobial agent, was studied by a standardized single disc method. A total of 990 clinical isolates were tested, including 20 strains of anaerobic bacteria. Ofloxacin was highly active against 683 strains (70.41%), had intermediate activity against 109 (11.23%) and had no activity against 178 (18.35%). Ofloxacin was highly active against E. coli, Klebsiella sp., Citrobacter sp., Proteus mirabilis, Proteus morganii, Salmonella sp., Campylobacter jejuni, Haemophilus influenzae, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Eubacterium sp., Propionibacterium acnes and Streptococcus sp. Pseudomonas sp., Serratia sp. and Proteus vulgaris had percentages of resistance to ofloxacin of 37.11%, 32% and 33.33% respectively. High percentages of resistance to ofloxacin were found only for Providencia sp., Proteus rettgeri and Bacteroides fragilis. With regard to Streptococcus faecalis, the results obtained with the disc procedure were not reliable and MIC determination was necessary to assess the behaviour of the drug.     

Antibacterial activity of cephem antibiotics against isolates from clinical specimens at the Yokohama City University Hospital

Minimum inhibitory concentrations (MICs) of cephem antibiotics against 405 strains belonging to 17 species of clinical isolates were investigated using the standard method of the Japanese Congress of Chemotherapy. The results obtained are summarized below. Cephem antibiotics showed weak antibacterial activities against Enterococcus sp., B. fragilis and S. marcescens. S. pneumoniae, S. agalactiae, E. coli, K. pneumoniae and P. mirabilis were susceptible to cephem antibiotics. Cephem antibiotics of the 1st and the 2nd generations showed weak antibacterial activity against Citrobacter sp. and E. cloacae, while cephem antibiotics of 3rd generation had a good antibacterial activity against these species. Cephem antibiotics of the 2nd and the 3rd generations showed high antibacterial activity against H. influenzae and indole positive Proteus group. Cefoperazone showed high antibacterial activity against P. aeruginosa. Resistance to latamoxef, ceftizoxime and cefoxitin was observed among Staphylococcus sp., while the MICs of other antibiotics against Staphylococcus sp. were fairly low. Number of strains resistant to the 3rd cephem antibiotics seems to be increasing because the 3rd generation of cephem antibiotics have been used frequently. Further investigation will be required on resistant organism to these antibiotics including beta-lactamase producing strains.     

Yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2001--II. Gram-negative bacteria

The in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates obtained between 1996 and 2001 were yearly evaluated and compared with those of other cephems, oxacephems and carbapenems. A total of 3,245 strains in 32 species of Gram-negative bacteria were isolated from the clinical materials annually collected from January to December, and consisted of Moraxella subgenus Branhamella catarrhalis, Escherichia coli, Citrobacter freundii, Citrobacter koseri, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus mirabillis, Proteus vulgaris, Morganella morganii, Providencia spp. (P. alcalifaciens, P. rettgeri, P. stuartii), Pseudomonas aeruginosa, Pseudomonas putida, Burkholderia cepacia, Stenotrophomonas maltophilia, Haemophilus influenzae, Acinetobactor baumannii, Acinetobactor lwoffii, Bacteroides fragilis group (B. fragilis, B. vulgatus, B. distasonis, B. ovatus, B. thetaiotaomicron), and Prevotella spp. (P. melaninogenica, P. intermedia, P. bivia, P. oralis, P. denticola). CZOP possessed stable antibacterial activities against M. (B.) catarrhalis, E. coli, C. freundii, C. koseri, K. pneumoniae, K. oxytoca, E. aerogenes, E. cloacae, S. marcescens, P. mirabilis, P. vulgaris, M. morganii, Providencia spp., P. aeruginosa, and A. lwoffii throughout 6 years. The MIC90 of CZOP against those strains were consistent with those obtained from the studies performed until the new drug application approval. On the other hand, the MIC90 of CZOP against H. influenzae yearly obviously increased with approximately 64-time difference during the study period. The MIC90 of cefpirome, cefepime, and flomoxef against H. influenzae also yearly tended to rise. The present results demonstrated that CZOP had maintained the antibacterial activity against almost Gram-negative strains tested. However, the decrease in antibacterial activities of CZOP against B. cepacia, and H. influenzae was suggested.     

Comparative in vitro potency of amoxycillin-clavulanic acid and four oral agents against recent North American clinical isolates from a global surveillance study

The in vitro activity of amoxycillin-clavulanic acid was compared with four comparator oral antimicrobial agents; ampicillin, azithromycin, cefuroxime and trimethoprim-sulphamethoxazole against 4536 recent clinical isolates covering 29 species isolated in the US and Canada between 1997 and 1999. Based upon Minimum inhibitory concentrations (MICs), amoxycillin-clavulanic acid was the most active agent against many Gram-positive species and phenotypes including methicillin susceptible Staphylococcus aureus (MSSA) Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes, Streptococcus pneumoniae including penicillin intermediate and macrolide resistant strains and was as active as ampicillin against Streptococcus agalactiae, penicillin resistant S. pneumoniae and viridans streptococci. Against Enterobacteriaceae amoxycillin-clavulanic acid in general, displayed weak activity with only Proteus mirabilis and Proteus vulgaris displaying levels of susceptibility above the 90th percentile. Amoxycillin-clavulanic acid had significant activity against many species of Gram-negative non-Enterobacteriaceae including Haemophilus influenzae, Haemophilus parainfluenzae and Moraxella catarrhalis but negligible activity against Burkholderia cepacia, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. Amoxycillin-clavulanic acid continues to retain excellent activity against the majority of targeted pathogens despite 20 years of clinical use.