Antibacterial activity of biapenem against recent clinical isolates

Antibacterial activity of biapenem (BIPM) against clinical isolates of 8 species between 2000 and 2002 was compared with those of imipenem/cilastatin (IPM/CS), meropenem (MEPM), panipenem/betamipron (PAPM/BP) and ceftazidime (CAZ). The MICs of biapenem for Gram-positive bacteria were higher than those of IPM/CS and PAPM/BP, equal to those of MEPM and lower than those of CAZ. The MICs of BIPM for Gram-negative bacteria were higher than those of MEPM, equal to those of IPM/CS and PAPM/BP, and lower than those of CAZ. Antibacterial activity of BIPM against Pseudomonas aeruginosa was equal to those of IPM/CS and MEPM and superior to those of PAPM/BP and CAZ. In conclusion, BIPM showed broad antibacterial activity against both Gram-positive and Gram-negative clinical isolates. These results suggest that BIPM is useful for the treatment of various bacterial infections.     

Antibacterial activity of rokitamycin against fresh clinical isolates]

We obtained bacterial strains which were clinically isolated and identified from outpatients with various infections in medical institutions throughout Japan. Possible antibacterial activities of rokitamycin (RKM) were examined against these isolates. Minimum inhibitory concentrations (MICs) were determined through a comparative study with reference drugs. The results of the study are summarized as follows. 1. Resistance patterns of 400 isolates which were highly resistant to macrolides (MLs) with MIC values > 100 micrograms/ml were classified into 55 patterns. Staphylococcus spp. showed cross resistance to 14-membered ring MLs with 100% cross resistance observed between erythromycin (EM) and clarithromycin (CAM), and 85.2% between EM and oleandomycin (OL). Fewer isolates showed strong resistance to 16-membered ring MLs than to 14-membered ring MLs. Cross resistances observed among the Staphylococcus isolates were 100% between acetylmidecamycin (MDM-AC) and kitasamycin (leucomycin (LM)), 93.9% between MDM-AC and josamycin (JM), and 53.3% between MDM-AC and RKM. Streptococcus spp. and Peptococcus spp. showed very similar resistance patterns to both 14- and 16-membered ring MLs, but resistance patterns to RKM were quite different. Most of anaerobic streptococci and Bacteroides fragilis group had similar resistance patterns to 14- and 16-membered ring MLs, but in some cases a pattern similar to that of Staphylococcus spp. was observed. 2. When ML-resistant bacteria isolated during 1975 to 1980 were compared to those isolated in 1986 and 1989, it was observed that resistance of Staphylococcus aureus remained almost unchanged, that of Streptococcus pyogenes was lower in the later years than during 1975 to 1980, but that of Streptococcus pneumoniae increased. 3. Most of ML-resistances of the resistant isolates were inducible, but extents of induction varied depending on drugs tested. Strong inductions were observed when 14-membered ring MLs were used, but inductions were minimal with 16-membered ring MLs. RKM appeared to induce resistance to the least extent. From these results, it appears that the RKM is quite useful clinically even in the 1990s.     

Antibacterial activity of norfloxacin against 1700 relatively resistant clinical isolates

A total of 1724 clinical isolates from patients with different infections were tested in vitro to determine their susceptibility to norfloxacin. Antibacterial activity of norfloxacin was compared with other drugs that were commonly used in the hospital. Of the 919 strains of Enterobacteriaceae tested, all except four isolates of Enterobacter, two of Serratia and one of Proteus were susceptible to norfloxacin. Ninety-five percent of the 199 strains of Pseudomonas aeruginosa were also inhibited by this quinolone. Brucella melitensis (81 strains) was completely susceptible to norfloxacin. All the 250 isolates of Staphylococcus aureus and coagulase-negative staphylococci were also sensitive to norfloxacin. Pseudomonads other than P.aeruginosa, Acinetobacter/Alcaligenes and group D streptococci were less sensitive to norfloxacin, with 56%, 57% and 20% respectively being inhibited by this antimicrobial agent.     

Antibacterial activity of cefmenoxime against clinical isolates. Comparative study

Antibacterial activity of cefmenoxime (CMX) against clinically isolated organisms was examined in comparison with that of 4 other antibiotics and concluded as follows: Antibacterial activity of CMX was markedly stronger than those of cefazolin (CEZ), cefmetazole, latamoxef and ampicillin against E. coli, K. pneumoniae, S. marcescens, H. influenzae, P. mirabilis and indole positive Proteus. But the MIC level of CMX against S. aureus was higher than that of CEZ.     

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.     

Antibacterial activity of panipenem against clinical isolates in 2000 and 2001

As the post-marketing surveillance of panipenem/betamipron (Carbenin), MICs of panipenem (PAPM) against 1355 clinical isolates of 28 species from 15 medical institutions all over Japan from June 2000 to March 2001 were measured using the broth microdilution method approved by the Japanese Society of Chemotherapy and compared with those of parenteral carbapenem antibacterials, imipenem (IPM) and meropenem (MEPM), and parenteral cephem antibacterials, cefozopran, cefepime, and sulbactam/cefoperazone. The activity of PAPM was comparable to that of IPM against almost all species tested. Compared with MEPM, PAPM was more active against Gram-positive bacteria and Bacteroides spp., and less active against Gram-negative bacteria. Compared with the parenteral cephems, PAPM was more active against most of species tested and its MIC ranges were narrower than those of the cephems as were those of other carbapenems. In this surveillance study, the incidence of resistance in various species were as follows: 39.3% for methicillin-resistant Staphylococcus aureus, 47.3% for penicillin-intermediate Streptococcus pneumoniae (PISP), 15.1% for penicillin-resistant S. pneumoniae (PRSP), 0.9% for extended-spectrum beta-lactamase (ESBL) producing Escherichia coli, 3.4% for ESBL producing Klebsiella pneumoniae, 19.2% for beta-lactamase producing Haemophilus influenzae, 24.0% for beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae, and 1.0% for metallo-beta-lactamase producing Pseudomonas aeruginosa. Against these resistant strains, carbapenems including PAPM showed generally more potent activity than cephems. It was noted that PAPM showed the most potent activity against PISP and PRSP, which showed high incidence of 62.4% totally, among tested drugs. Metallo-beta-lactamase producing P. aeruginosa exhibited high resistance and BLNAR H. influenzae also exhibited low susceptibility against all tested drugs. But no remarkable change in the activity of PAPM against other species was observed in this study compared with that in the studies before the marketing of Carbenin. Furthermore, it is necessary to pay much attention to the trend of resistant strains such as PRSP, metallo-beta-lactamase producing bacteria, and BLNAR H. influenzae.     

Antibacterial activity of cefpodoxime against clinical isolates in 2000 and 2001

As the post-marketing surveillance of cefpodoxime proxetil (Banan), MICs of cefpodoxime (CPDX, an active form of Banan) against 1090 clinical isolates of 22 species from 15 medical institutions all over Japan from June 2000 to March 2001 were measured using the broth microdilution method approved by the Japanese Society of Chemotherapy and compared with those of oral cephem antibacterials, cefaclor, cefdinir, cefditoren, and cefcapene. In this study, remarkable change in the activity of CPDX was observed in Streptococcus pneumoniae and Haemophilus influenzae compared with the susceptibility in the studies before Banan was launched. This cause is considered to be the increase in the incidence of the following resistant strains: penicillin-intermediate S. pneumoniae (47.3%), penicillin-resistant S. pneumoniae (PRSP, 15.1%), and beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae (24.0%), which were scarcely isolated in 1989 when Banan was launched. Other tested drugs also exhibited low activity against these resistant strains. However, CPDX showed comparatively good activity with MIC90 of 2 micrograms/mL against PRSP. Against methicillin-susceptible Staphylococcus spp., Streptococcus pyogenes, Streptococcus agalactiae, and Moraxella catarrhalis, CPDX also showed comparatively good activity with MIC90 of < or = 4 micrograms/mL, which was almost equal to that in the studies before its marketing. Against quinolones-resistant Neisseria gonorrhoeae, CPDX showed excellent activity with MIC90 of 0.5 microgram/mL. Against members of the family Enterobacteriaceae except for Citrobacter freundii, Enterobacter spp., Proteus vulgaris, and Morganella morganii, CPDX showed good activity. However, in Escherichia coli, Klebsiella spp. Proteus spp., and Providencia spp., there are some high-resistant strains to all tested drugs including CPDX. Against Peptostreptococcus spp., MIC90 of CPDX was 8 micrograms/mL and its MIC range was widely distributed from 0.03 to 32 micrograms/mL, which were similar to those in the studies before its marketing. In this study, CPDX showed the decrease in the activity against several species as did other drugs tested, but against most of species tested, CPDX maintained good activity. Furthermore, it is necessary to pay much attention to the trend of resistant strains.     

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.     

Antibacterial activity of ciprofloxacin against fresh clinical isolates from superficial suppurative foci

The minimum inhibitory concentrations (MICs) of 5 drugs (ciprofloxacin (CPFX), and 4 drugs used as standard) were determined to investigate antibacterial potencies of CPFX against bacterial strains isolated in 1989 from superficial suppurative foci. The clinical isolates tested included 375 strains from 11 aerobic bacterial species, and 50 strains from 2 anerobic bacterial genera (group) for a total of 425 isolates. Interpreting MIC level distributions of these drugs as the expression of antibacterial potencies, the results are as follows. 1. When activities of new-quinolone antibiotics were tested, we found that, CPFX expressed far superior antibacterial potency to ofloxacin (OFLX) and norfloxacin (NFLX) against coagulase-negative staphylococci, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Pseudomonas aeruginosa and Peptostreptococcus spp., although the activity of CPFX against Bacteroides fragilis group was weaker than that of OFLX, and CPFX had similar activity against Staphylococcus aureus to OFLX. 2. In comparison to beta-lactam antibiotics, CPFX was inferior to amoxicillin (AMPC) against E. faecalis and inferior to AMPC and cefaclor (CCL) against Peptostreptococcus spp. Against all other bacterial species, however, CPFX expressed superior antibacterial potency to AMPC and CCL. 3. Scattered findings of low sensitivity or resistance to CPFX were observed among the S. aureus, E. faecalis, E. faecium, P. vulgaris, M. morganii, P. aeruginosa and B. fragilis (group) species, but with an exception of E. faecium, the incidence of resistance strains was low.     

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)     

Antibacterial activity of cefotiam against clinical isolates in the field of obstetrics and gynecology

Antibacterial activity of cefotiam (CTM) against clinically isolated organisms in the field of obstetrics and gynecology was discussed as follows: In the point of view of the MICs peak, CTM was 1-fold worse than CEZ against Gram-positive bacteria, while, in the case of the concentration of CTM required to inhibit the growth of 80% or 90% of the total number of tested Gram-positive organism, antibacterial activity of CTM was approximately identical with that of CEZ, CMZ or SBPC. CTM against E. coli, K, pneumoniae, P. Mirabilis was 16-32-fold more effective than CEZ and 4-16-fold than CMZ. Against indole-positive organisms with CEZ was no effective, CTM was considerably effective. But antibacterial activity of CTM against B. fragilis was insufficient. However, in the case that no spore forming anaerobic organism involved in infectious disease, it is said that existence of aerobic organism is important. As E. coli is representative of aerobic organism, CTM with potent antibacterial activity against this organism is seemed to be effective antibiotic for the gynecological infection.     

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.     

Antibacterial activity in spices and local medicinal plants against clinical isolates of Karachi,Pakistan

Context: Development of resistance in human pathogens against conventional antibiotic necessitates searching indigenous medicinal plants having antibacterial property. Twenty-seven medicinal plants used actively in folklore, ayurvedic and traditional system of medicine were selected for the evaluation of their antimicrobial activity for this study. Eleven plants chosen from these 27 are used as spices in local cuisine.

Objective: Evaluation of the effectiveness of some medicinal plant extracts against clinical isolates.

Material and methods: Nonedible plant parts were extracted with methanol and evaporated in vacuo to obtain residue. Powdered edible parts were boiled three times and cooled in sterile distilled water for 2?min each and filtrate collected. The minimum inhibitory concentration (MIC) of plant extracts and filtrates/antibiotics was evaluated against clinical isolates by microbroth dilution method.

Results: Water extract of Syzygium aromaticum L. (Myrtaceae) buds, methanol extracts of Ficus carica L. (Moraceae) and Olea europaea L. (Oleaceae) leaves and Peganum harmala L. (Nitrariaceae) seeds had MIC ranges of 31.25–250 µg/ml. S. aromaticum inhibited growth of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Salmonella enterica serovar Typhi and Pseudomonas aeruginosa. F. carica and O. europaea inhibited growth of S. aureus, S. epidermidis, and S. pyogenes whereas P. harmala was effective against S. aureus, Acinetobacter calcoaceticus and Candida albicans. Ampicillin, velosef, sulfamethoxazole, tetracycline and ceftazidime, cefotaxime, cefepime, which are used as control, had MIC ≥50 and 1.5 µg/ml, respectively, for organisms sensitive to extracts.

Discussion and conclusion: Mono/multiextract from identified plants will provide an array of safe antimicrobial agents to control infections by drug-resistant bacteria.     

替加环素对临床常见菌的体外抗菌活性

目的评价替加环素(四环素类抗生素)对临床常见菌的体外抗菌活性。方法应用微量肉汤稀释法,对替加环素等14种药物对近2年本院临床标本中所分离的400株菌进行MIC测定,用WHONET5.4软件进行统计。结果 MIC测定结果显示:替加环素对甲氧西林耐药葡萄球菌(MRSA)和肠球菌显示了良好的体外抗菌活性,试验中有3株万古霉素耐药肠球菌(VRE),对替加环素和利奈唑胺显示敏感;对革兰阴性菌中产ESBL的大肠埃希菌和克雷伯菌属MIC90均为1μg.mL-1,仅次于或低于美罗培南;本研究中替加环素对鲍曼不动杆菌的MIC90(2μg.mL-1)在所有检测抗菌药物中最低;对铜绿假单胞菌的MIC90值为16μg.mL-1。结论替加环素对临床常见病原菌具有良好的广谱抗菌活性,对铜绿假单胞菌抗菌活性较差。     

Antibacterial activity of liposomal gentamicin against Pseudomonas aeruginosa: a time-kill study

Cystic fibrosis (CF) is a common and lethal genetic disorder with a carrier frequency of 1 in 29 Caucasians. Chronic respiratory infections with Pseudomonas aeruginosa are the leading cause of morbidity and mortality in individuals with CF. Aminoglycoside antibiotics, including gentamicin, are highly effective against P. aeruginosa, but severe toxicity limits their use. One potential strategy for avoiding this problem is to encapsulate aminoglycosides in liposomes. In this study, we compared the bactericidal capacity of liposome-encapsulated gentamicin with that of free antibiotic against clinical isolates of P. aeruginosa. Liposome size, encapsulation efficiency and minimal inhibitory concentrations (MICs) of the free and liposomal gentamicin against gentamicin-sensitive and -resistant strains of P. aeruginosa were determined. In vitro time-kill studies were performed using free and liposomal gentamicin at 1, 2 or 4 times the MICs. The average liposomal size was 426.25 +/- 13.56 nm, with a gentamicin encapsulation efficiency of 4.51 +/- 0.54%. The MICs for liposomal gentamicin were significantly lower than those of corresponding free gentamicin. In addition, the time-kill values for liposomal gentamicin were either equivalent to or better than those of the free antibiotic. In conclusion, our liposomal gentamicin formulation is a more potent antipseudomonal drug with an improved killing time and prolonged antimicrobial activity.     

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.     

Susceptibility of clinical isolates in pediatrics to cefpiramide

Cefpiramide (CPM, SM-1652) had broad-spectrum antibacterial activities against most of clinically isolated organisms to which are paid attention as pathogenic organism in the field of pediatrics. Antibacterial activities of CPM against Staphylococcus aureus, Streptococcus pyogenes, Haemophilus influenzae, Bordetella pertussis and Proteus mirabilis were almost the same as those of cefoperazone (CPZ). Antibacterial activities of CPM against Escherichia coli and Klebsiella pneumoniae were somewhat weaker than those of CPZ, but antibacterial activity of CPM against Pseudomonas aeruginosa was rather stronger than that of CPZ and almost the same as that of cefsulodin. Antibacterial activity of CPM has a tendency to decrease in beta-lactamase (PCase type) producing S. aureus, E. coli, K. pneumoniae, H. Influenzae, etc. It is suggestive that the determination of not only the antibacterial activity of CPM against pathogenic organisms but also the beta-lactamase producing activity of them is important on the occasion of clinical use of CPM.     

In-vitro activity of panipenem against clinical isolates in 2006

The antimicrobial activity of various antibiotics against clinical bacterial isolates recovered from patients with infectious diseases at the medical facilities in the Kanto region between March and September 2006 was evaluated. A total of 1030 clinical isolates were available for susceptibility tests: 420 aerobic Gram-positive organisms, 520 aerobic Gram-negative organisms, 30 anaerobic Gram-positive organisms and 60 anaerobic Gram-negative pathogens. Antimicrobial susceptibility data for Streptococcus pneumoniae and Haemophilus influenzae isolates from pediatric and adult patients were analyzed separately. Panipenem (PAPM), imipenem (IPM), meropenem (MEPM), biapenem (BIPM), doripenem (DRPM), cefozopran (CZOP), cefepime (CFPM), and sulbactam/cefoperazone (SBT/CPZ) were used as test antibiotics. PAPM, IPM and DRPM exhibited excellent in vitro antibacterial activities against methicillin-susceptible Staphylococcus, with all isolates exhibiting a MIC of < or =0.06 microg/mL. Against Streptococcus including penicillin-resistant S. pneumoniae, PAPM demonstrated the strongest antibacterial activity among the carbapenems with a MIC range of < or =0.06 to 0.12 microg/mL. Against Enterobacteriaceae, MEPM showed the strongest antibacterial activity, and PAPM had comparable activity to IPM. Against the extended-spectrum beta-lactamase producing Escherichia coli, Klebsiella species and Proteus species, the MICs for the cephems were high, however, those for the carbepenems were low. Against H. influenzae, PAPM had comparable activity to IPM. With respect to anaerobes, each of the carbapenems tested demonstrated almost the same strong antibacterial activity. In conclusion, 13 years has passed since PAPM was launched in 1993, PAPM still maintains potent antibacterial activity and is considered an effective antimicrobial agent for various types of infectious diseases.     

Antimicrobial activity of imipenem against 1386 clinical isolates

1386 isolates from clinical specimens were tested against imipenem by disc agar diffusion. The bacteria used in this study consisted of Escherichia coli, Enterobacter aerogenes, E. agglomerans, E. cloacae, Klebsiella pneumoniae, K. oxytoca, K. ozanae, Proteus mirabilis, P. vulgaris, Providencia stuartii, P. rettgeri, Acinetobacter calcoaceticus, Citrobacter diversus, C. freundii, Morganella morganii, Serratia liquefaciens, S. marcescens, Hafnia alvei, Aeromonas hydrophila, Pseudomonas aeruginosa, P. cepacia, P. maltophila, P. fluorescens, Staphylococcus aureus, S. epidermidis, S. saprophyticus, pneumococcus, Lancefield group A, B and D streptococci, viridans streptococci, diphtheroids and Bacillus species. In vitro activity of imipenem was compared with the following antibiotics: ampicillin, amikacin, carbenicillin, cefoperazone, cefoxitin, cephalothin, chloramphenicol, clindamycin, colistin, erythromycin, gentamicin, methicillin, penicillin, tetracycline, tobramycin, trimethoprim-sulfamethoxazole and vancomycin. Of the 819 strains of Enterobacteriaceae tested, 99.5% were susceptible to imipenem. Ninety-seven percent strains of P. aeruginosa were also susceptible to imipenem. All the 161 isolates of S. aureus and 116 of the 117 isolates of enterococci exhibited in vitro susceptibility to this antibiotic. All gram positive bacteria tested were inhibited by imipenem except 28% isolates of S. epidermidis and 5% isolates of S. agalactiae.