Decreased nitrogen rates and irrigation effect on celery yield and internal quality

Sparfloxacin, a new orally administered fluoroquinolone, was tested against 14,182 clinical strains isolated (generally blood stream and respiratory tract cultures) at nearly 200 hospitals in the United States (USA) and Canada. Sparfloxacin activity was compared with 13 other compounds by Etest (AB BIODISK, Solna, Sweden), broth microdilution, or a standardized disk diffusion method. Using the Food and Drug Administration/product package insert MIC breakpoint for sparfloxacin susceptibility (< or = 0.5 microgram/ml), 94% of Streptococcus pneumoniae (2666 isolates) and 89% of the other streptococci (554 isolates) were susceptible. However, at < or = 1 microgram/ml (the breakpoint for all nonstreptococcal species) sparfloxacin susceptibility rates increased to 100% and 98%, respectively, for the two groups of streptococci. Only 50% and 65% of pneumococci were susceptible to ciprofloxacin (MIC90, 3 micrograms/ml) and penicillin (MIC90, 1.5 micrograms/ml), respectively. Although there were significant differences between regions in the USA in the frequency of penicillin-resistant pneumococcal strains, results indicate that the overall sparfloxacin MIC90 was uniformly at 0.5 microgram/ml. Nearly all (> or = 99%) Haemophilus species and Moraxella catarrhalis, including those harboring beta-lactamases, were susceptible to sparfloxacin, ciprofloxacin, and amoxicillin/clavulanic acid. Only cefprozil and macrolides demonstrated lower potency and spectrum against these two species. Sparfloxacin was active against oxacillin-susceptible Staphylococcus aureus (96 to 97%), Klebsiella spp. (95%), and other tested enteric bacilli (93%). Comparison between broth microdilution MIC and disk diffusion interpretive results for M. catarrhalis, Staphylococcus aureus, and the Enterobacteriaceae showed an absolute intermethod categorical agreement of > 95% using current sparfloxacin breakpoints, in contrast to those of cefpodoxime for S. aureus where a conspicuous discord (98% versus 59%) between methods was discovered. These results demonstrate that sparfloxacin possesses sufficient in vitro activity and spectrum versus pathogens that cause respiratory tract infections (indications), especially strains resistant to other drug classes such as the earlier fluoroquinolones, oral cephalosporins, macrolides, and amoxicillin/clavulanic acid. The sparfloxacin susceptibility breakpoint for streptococci may require modification (< or = 1 microgram/ml) based on the MIC population analysis presented here. A modal MIC (0.38 to 0.5 microgram/ml) was observed at the current breakpoint. Regardless, sparfloxacin inhibited 89% (nonpneumococcal Streptococcus spp.) to 100% (Haemophilus spp., M. catarrhalis) of the isolates tested with a median activity of 97% against indicated species.     

In vitro antimicrobial activity of fluoroquinolones against clinical isolates obtained in 1989 and 1990

The in vitro activity of nine fluoroquinolones, enoxacin, norfloxacin, ofloxacin, ciprofloxacin, lomefloxacin, tosufloxacin, sparfloxacin, fleroxacin and levofloxacin, and two earlier quinolones, nalidixic acid and pipemidic acid, against 1,346 bacterial strains isolated clinically between 1989 and 1990, was evaluated by agar dilution method. The bacteria studied were Staphylococcus aureus (including methicillin-susceptible and -resistant strains), Staphylococcus epidermidis, Enterococcus species (including high-level gentamicin-resistant strains), Escherichia coli, Salmonella species, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Citrobacter spp., Pseudomonas aeruginosa, Pseudomonas cepacia, Acinetobacter baumannii, and Bacteroides fragilis. In contrast to the moderate to poor activity of two earlier quinolones, the fluoroquinolones acted well against most Enterobacteriaceae and A. baumannii. The minimum inhibitory concentrations for 90% of the drug strains (MIC90s) were < 1 microgram/mL against most tested species. Ciprofloxacin, tosufloxacin, sparfloxacin, and levofloxacin were more effective against multi-drug-resistant nosocomial pathogens. All fluoroquinolones assayed were very active against methicillin-susceptible S. aureus, with MIC90s < or = 1 microgram/mL. For methicillin-resistant strains, on the other hand, the MIC90s were > or = 4 micrograms/mL. There was no significant difference in fluoroquinolone susceptibility between methicillin-susceptible and -resistant S. epidermidis. Sparfloxacin, tosufloxacin, ciprofloxacin and levofloxacin were more active against enterococci. Most fluoroquinolones were relatively inactive against B. fragilis, with the exception of tosufloxacin, sparfloxacin and levofloxacin. The MIC90s of most quinolones assayed against K. pneumoniae, Citrobacter spp., E. cloacae, S. aureus and S. epidermidis were at least four-fold higher in our study. Therefore, it is important for physicians to use fluoroquinolones carefully so as to prevent or delay the emergence of resistant strains.     

In vivo antibacterial activities of sanfetrinem cilexetil, a new oral tricyclic antibiotic

The in vivo antibacterial activities of a new oral trinem, sanfetrinem cilexetil (a prodrug of sanfetrinem), were evaluated in comparison with those of cefdinir and amoxicillin. Sanfetrinem cilexetil showed potent efficacy against experimental murine septicemia caused by Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli and against murine respiratory infections caused by Streptococcus pneumoniae. Likewise, in murine models of respiratory infection by penicillin-susceptible and penicillin-resistant S. pneumoniae, sanfetrinem cilexetil was more effective than amoxicillin in reducing the number of bacteria in infected lungs. These results were reflected in its potent in vitro activity and high levels in plasma.     

Antimicrobial activity of fluoroquinolones and other antibiotics on 1,116 clinical gram-positive and gram-negative isolates

A total of 1,116 clinically isolated strains belonging to Staphylococcus aureus (200), Staphylococcus epidermidis (200), Streptococcus pneumoniae (20), Escherchia coli (200), Klebsiella spp. (177), Serratia marcescens (22), Pseudomonas aeruginosa (224), Haemophilus influenzae (35) and Salmonella (38) from the Department of Infectious Diseases, La Sapienza University in Rome (Italy) were tested against three fluoroquinolones (ofloxacin, ciprofloxacin and levofloxacin) and 10 other antibiotics (augmentin, ampicillin, cefaclor, cefixime, cefotaxime, cotrimoxazole, gentamicin, minocycline, oxacillin and vancomycin). Fluoroquinolones inhibited essentially about 100% of H. influenzae, Salmonella and S. pneumoniae, more than 75% of Staphylococcus including methicillin-resistant strains, and about 90% of Enterobacteriaceae and 50% of P. aeruginosa. Minimal inhibitory concentration values ranged from < 0.015 to > 32 micrograms/ml for Klebsiella, S. aureus and epidermidis, E. coli and P. aeruginosa; from < 0.015 to 2 micrograms/ml for Salmonella; from 0.03 to 16 micrograms/ml for Serratia; from < 0.015 to 1 microgram/ml for Haemophilus; and from 0.5 to 2 micrograms/ml for S. pneumoniae. Levofloxacin and to a lesser extent ofloxacin and ciprofloxacin, generally exhibited a greater activity than the other agents against both Gram-positive and Gram-negative bacteria. Regarding the distribution of resistant strains in Italy, we found a peculiar pattern of resistance as far as E. coli and P. aeruginosa were concerned. Quality control parameters are also summarized. S. epidermidis resulted as a new emergent pathogen especially in immunocompromised patients and its level of sensitivity has been modified over the last few years. In fact, the percentage of resistant strains to antibiotics or the percentage of methicillin-resistant isolates (in our study 35%), has gradually increased. Levofloxacin and ofloxacin showed good activity against staphylococcal strains compared with the majority of other antibiotics. These results suggest that the newer quinolones are promising antimicrobial agents for various infections.     

Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1996)

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In 16 institutions around the entire Japan, 557 strains of presumably etiological bacteria were isolated mainly from the sputa of 449 patients with lower respiratory tract infections during the period from October 1996 to September 1997. MICs of various antibacterial agents and antibiotics were determined against 98 strains of Staphylococcus aureus, 93 strains of Streptococcus pneumoniae, 84 strains of Haemophilus influenzae, 84 strains of Pseudomonas aeruginosa (non-mucoid strains), 17 strains of Pseudomonas aeruginosa (mucoid strains), 31 strains of Moraxella subgenus Branhamella catarrhalis, 21 strains of Klebsiella pneumoniae etc., and the drug susceptibilities of these strains were assessed except for those strains that died during transportation. 1) S. aureus S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus) accounted for 67.3%. The frequency of the drug resistant bacteria increased comparing to the previous year's 52.7%. Arbekacin (ABK) and vancomycin (VCM) showed the highest activities against both S. aureus and MRSA with MIC80s of 1 microgram/ml. 2) S. pneumoniae Imipenem (IPM) and panipenem (PAPM) of carbapenems showed the most potent activities with MIC80s of 0.063 microgram/ml. Faropenem (FRPM) showed the next potent activity with MIC80 of 0.125 microgram/ml. The other drugs except erythromycin (EM), clindamycin (CLDM) and tetracycline (TC) were active against S. pneumoniae tested with MIC80s of 8 micrograms/ml or below. 3) H. influenzae The activities of all drugs were potent against H. influenzae tested with MIC80s of 4 micrograms/ml or below. Cefotiam (CTM), cefmenoxime (CMX), cefditoren (CDTR) and ofloxacin (OFLX) showed the most potent activities with MIC80s of 0.063 microgram/ml. 4) P. aeruginosa (mucoid strains) Tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains) with MIC80 of 1 microgram/ml. Ceftazidime (CAZ), cefsulodin (CFS), IPM, gentamicin (GM), ABK and ciprofloxacin (CPFX) showed the next potent activities, with MIC80s of 2 micrograms/ml. The MIC80s of the other drugs ranged from 4 micrograms/ml to 16 micrograms/ml. 5) P. aeruginosa (non-mucoid strains) TOB and CPFX showed the most potent activities against P. aeruginosa (non-mucoid strains) with MIC80s of 1 microgram/ml. The MIC80s of piperacillin (PIPC) and cefoperazone (CPZ) were 16 micrograms/ml in 1995, and they were 64 micrograms/ml in 1996. 6) K. pneumoniae All drugs except ampicillin (ABPC) were active against K. pneumoniae. CMX, cefpirome (CPR), cefozopran (CZOP) and carumonam (CRMN) showed the most potent activities against K. pneumoniae with MIC80s of 0.125 microgram/ml. The MIC80s of the other drugs ranged from 0.25 microgram/ml to 2 micrograms/ml. 7) M.(B) catarrhalis Against M.(B.) catarrhalis, all drugs showed good activities with MICs of 4 micrograms/ml or below. IPM and minocycline (MINO) showed the most potent activities with MICs of 0.063 microgram/ml. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. Patients' backgrounds were examined for 557 isolates from 449 cases. The examination of age distribution indicated that the proportion of patients with ages over 60 years was 71.0% of all the patients showing a slight increase over that in 1994. Proportions of diagnosed diseases were as follows: Bacterial pneumonia and chronic bronchitis were the most frequent with 35.9% and 30.3% respectively. They were followed by bronchiectasis with a proportion of 10.     

Primary extranodal non-Hodgkin''s lymphomas. Part 1: Gastrointestinal, cutaneous and genitourinary lymphomas

We investigated the clinical efficacy in pediatrics sinusitis infections of cefditoren pivoxil granule therapy and its in vitro antibacterial activity against clinically isolated strains. The results are summarized as follows. The specimens from 343 patients were cultured and 595 strains of bacteria were isolated and identified. Oral doses of 3 and 5 mg/kg of CDTR-PI were clinically effective at high percentages, 85.1% and 89.5%, respectively, of treated patients. CDTR-PI at 3 mg/kg orally was clinically effective in 80.8% of patients with PCG intermediate S. pneumoniae (PISP) infections, 80.0% of those with PCG susceptible S. pneumoniae (PSSP) infections, 81.8% of those with H. influenzae infections and 78.3% of those with M. (B.) catarrhalis infections among the infections by major causative agents. The frequent isolates included S. pneumoniae accounting for 33.1%, H. influenzae accounting for 32.1%, M. (B.) catarrhalis accounting for 17.6% and S. pyogenes accounting 3.7% of all the isolates. PISP accounted for 16.1% of all the isolates and for 49.8% of the isolates of S. pneumoniae, and were isolated from 28.6% of the 343 patients. The isolation of PISP was frequent from children of 4 and under especially, and especially frequent from those below age 2. Of the isolates of S. pneumoniae, the biotype frequencies among PSSP were in the order of type I > type II > type III, while those among PISP were in the order of type I < type II with none of type III. Bacteriologically, an eradication rate of 89.4% was achieved with 3 mg/kg and 93.5% with 5 mg/kg of CDTR-PI.     

Efficacy of cefditoren pivoxil in the treatment of acute otitis media due to benzylpenicillin-insensitive Streptococcus pneumoniae

Clinical and bacteriological studies were carried out on cefditoren pivoxil (CDTR-PI) granule in infantile purulent acute otitis media treated at general practice settings and the following findings were obtained: 1. Two hundred forty eight strains were isolated from 210 patients, almost all of which (81.1%) harbored the following two strains: Streptococcus pneumoniae (42.3%) and Haemophilus influenzae (38.8%). Among S. pneumoniae, benzylpenicillin (PCG)-insensitive S. pneumoniae, (PISP) or PCG-resistant S. pneumoniae (PRSP) was 36.2%, corresponding to 15.3% of all the isolates and found in 18% of all patients. 2. The bacteria in the middle ear discharge and the nasopharyngeal swabs were correlated with conformity rate of more than 80% with regard to Streptococcus pyogenes, S. pneumoniae and H. influenzae but no Staphylococcus aureus was detected simultaneously from the two sources in any of the patients. S. aureus and coagulase-negative staphylococci (CNS) were considered to be contaminants that were originated from the external auditory meatus at the time of sampling. 3. Frequencies of isolation of S. pneumoniae from different age groups were higher in a lower age group between 0 and 4 years and those of PISP or PRSP had the similar tendency. 4. Antibacterial activities were determined for CDTR and related oral antibiotics against the strains of S. pneumoniae and H. influenzae as representative isolates. CDTR had stronger antibacterial activities against both bacteria than the reference antibiotics. CDTR was found to be transferred into the otorrhea at a mean concentration of 0.58 micrograms/ml after single administration of CDTR-PI granule formulation at 3 mg(potency)/kg. 5. As for bacterial eradication efficacies in the middle ear cavity and the nasopharynx, eradication rates were higher than 80% in the middle ear cavity in all cases without large differences among bacterial species but eradication rate of PISP was 30% in the nasopharynx, and it was significantly lower than those of PSSP and other bacteria. 6. In view of clinical effectiveness, the efficacy rate was 89.4% and bacteriological effects was 92.2%; in view of safety, adverse reactions were; observed in 9.5% and the rate of usefulness was 89.4%. 7. From above-stated results, CDTR-PI was considered as a useful oral antibiotic for infantile acute otitis media including PISP infections.     

Clinical and bacteriological effects of cefetamet pivoxil against community-acquired respiratory tract infections. Part II

We investigated clinical and bacteriological effects of cefetamet pivoxil (CEMT-PI) in community-acquired respiratory tract infections and obtained the following findings. That method was approximately equal to that of investigation in 1994. 1. Of the 431 respiratory tract infection cases that were treated with CEMT-PI according to a same protocol at a total of 41 institutions in Tokyo, Kanagawa-ken, Saitama-ken and Chiba-ken from January to the beginning of March 1996. Outpatients accounted for 98.1% of the subjects. Regarding genders to patients, slightly more females (52.6%) than males were included. Diagnoses given to these patients included pharyngo-laryngitis (53.5%), tonsillitis (20.4%) and acute bronchitis (19.1%). 2. We investigated clinical efficacy rates (the ratio of those excellent + good) classified by diseases. The improvement rates of pharyngo-laryngitis, tonsillitis and acute bronchitis were more than 85.0%. Other cases were small in number. That of chronic bronchitis-acute increasing change for the worse was 66.7%, pneumonia was 50.0% and bronchiectasis infection was 16.7%. It was not studied that clinical efficacy rates among those who were treated with 1 CEMT-PI tablet twice and among those who were given 2 tablets twice were significant level. 3. For the bacteriological study, a written material describing the method of collecting specimens, storage and transport in detail was distributed to the above mentioned institutions. The isolation and identification of suspected causative bacteria, determination of minimum inhibitory concentrations (MICs) and investigation of beta-lactamase production were conducted all together at section of studies, Tokyo Clinical Research Center. Suspected causative bacteria were detected from 274 (63.6%) cases. They included 88 strains of Haemophilus influenzae, 47 strains of Streptococcus pneumoniae, 42 strains of Streptococcus pyogenes, 20 strains of Moraxella subgenus Branhamella catarrhalis and 17 strains of Klebsiella pneumoniae subsp. pneumoniae. Suspected causative bacteria classified by diseases were S. pyogenes (tonsillitis), S. pneumoniae (acute bronchitis and secondary infection of chronic respiratory infection) and H. influenzae (pharyngo-laryngitis), and the detection frequency of those was high. The clinical efficacies (the ratio of improvement) classified by suspected causative bacteria were 84.4% against organism that was indicating CEMT and were 69.2% against organism that was not indicating CEMT.     

Ceftezole, a new cephalosporin C derivative I. In vitro and in vivo antimicrobial activity

Ceftezole, a new cephalosporin antibiotic similar to cefazolin, has the following chemical structure: (6R,7R)-8-oxo-7[2-(1H-tetrazol-1-yl)acetamido]-3-[(1,3,4-thiadiazol-2-ylthio)methyl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-carboxylic acid. Ceftezole was found to be a broad-spectrum antibiotic, active in vitro against many species of gram-positive and gram-negative bacteria except Pseudomonas aeruginosa, Serratia marcescens and Proteus vulgaris. The activity of ceftezole against clinical isolates of Escherichia coli and Klebsiella spp. appeared to be nearly equal to that of cefazolin and higher than those of cephaloridine and cephalothin. Cross-resistance was observed between ampicillin and cephaloridine, but not between ampicillin and ceftezole, in susceptibility tests on clinical isolates of P. mirabilis. The in vitro activity was little affected by the inoculum size, the presence of human serum or the test medium. Ceftezole exhibited apparent bactericidal activity at the concentrations above the minimum inhibitory concentration (MIC) against both S. aureus and E. coli. The development in vitro of resistance by S. aureus 209p and E. coli NIHJ to ceftezole after 16 transfers was similar to or somewhat slower than that to other drugs tested. Ceftezole was relatively stable in nutrient broth and minimally degraded in the serum or tissue homogenates of rats. Ceftezole, in a single subcutaneous administration, exhibited somewhat less efficacy in mice against intraperitoneal infections with Streptococcus pyogenes, S. pneumoniae, E. coli, K. pneumoniae or P. mirabilis than either cephaloridine or cefazolin. However, ceftezole exhibited efficacy similar to that of cephaloridine or cefazolin when administered in three doses. Furthermore, ceftezole was as effective as cefazolin in the treatment of experimental abscesses in mice caused by subcutaneous inoculation with S. aureus.     

Activities of new fluoroquinolones against fluoroquinolone-resistant pathogens of the lower respiratory tract

The activities of six new fluoroquinolones (moxifloxacin, grepafloxacin, gatifloxacin, trovafloxacin, clinafloxacin, and levofloxacin) compared with those of sparfloxacin and ciprofloxacin with or without reserpine (20 microg/ml) were determined for 19 Streptococcus pneumoniae isolates, 5 Haemophilus sp. isolates, and 10 Pseudomonas aeruginosa isolates with decreased susceptibility to ciprofloxacin from patients with clinically confirmed lower respiratory tract infections. Based upon the MICs at which 50% of isolates were inhibited (MIC50s) and MIC90s, the most active agent was clinafloxacin, followed by (in order of decreasing activity) trovafloxacin, moxifloxacin, gatifloxacin, sparfloxacin, and grepafloxacin. Except for clinafloxacin (and gatifloxacin and trovafloxacin for H. influenzae), none of the new agents had improved activities compared with that of ciprofloxacin for P. aeruginosa and H. influenzae. A variable reserpine effect was observed for ciprofloxacin and S. pneumoniae; however, for 9 of 19 (47%) isolates the MIC of ciprofloxacin was decreased by at least fourfold, suggesting the presence of an efflux pump contributing to the resistance phenotype. The laboratory parC (Ser79) mutant strain of S. pneumoniae required eightfold more ciprofloxacin for inhibition than the wild-type strain, but there was no change in the MIC of sparfloxacin and only a 1-dilution increase in the MICs of the other agents. For efflux pump mutant S. pneumoniae the activities of all the newer agents, except for levofloxacin, were reduced. Except for clinafloxacin, all second-step laboratory mutants required at least 2 microg of all fluoroquinolones per ml for inhibition.     

Studies of the killing kinetics of benzylpenicillin, cefuroxime, azithromycin, and sparfloxacin on bacteria in the postantibiotic phase

Most antibiotics are known to be incapable of killing nongrowing or slowly growing bacteria with few exceptions. Bacterial cell division is inhibited during the postantibiotic phase (PA phase) after short exposure to antibiotics. Only scarce and conflicting data are available concerning the ability of antibiotics to kill bacteria in the PA phase. The aim of the present study was to investigate the killing effect of four different antibiotics on bacteria in the PA phase. A postantibiotic effect (PAE) was induced by exposing Streptococcus pyogenes and Haemophilus influenzae to 10x MICs of benzylpenicillin, cefuroxime, sparfloxacin, and azithromycin. The bacteria were thereafter reexposed to a 10x MIC of the same antibiotic used for the induction of the PAE at the beginning of and after 2 and 4 h in the PA phase. Due to a very long PAE, the bacteria in PA phase induced by azithromycin were also exposed to 10x MICs after 6 and 8 h. A previously unexposed culture exposed to a 10x MIC was used as a control. The results seem to be dependent on both the antibiotic used and the bacterial species. The antibiotics exhibiting a fork bactericidal action gave significantly reduced killing of the bacteria in PA phase (cefuroxime with S. pyogenes, P < 0.01, and sparfloxacin with H. influenzae, P < 0.001), which was restored at 4 h for cefuroxime with S. pyogenes. There was a tendency to restoration of the bactericidal activity also with sparfloxacin and H. influenzae, but there was still a significant difference in killing between the control and the test bacteria in PA phase at 4 h. However, in the combinations with a lesser bactericidal effect (benzylpenicillin with S. pyogenes and sparfloxacin with S. pyogenes), there was no difference in killing between the control and the test bacteria in PA phase. Azithromycin induced long PAEs in both S. pyogenes and H. influenzae and exhibited a slower bactericidal action on both the control and the bacteria in PA phase especially at the end of the PAE, when the killing was almost bacteriostatic. Our findings in this study support the concept that a long interval (> 12 h) between doses of azithromycin, restoring full bactericidal action, may be beneficial to optimize efficacy of this drug but is not necessary for the other antibiotics evaluated, since the bactericidal effect seems to be restored already at 4 h.     

Recent trends in incidence of respiratory tract pathogens and antimicrobial susceptibilities of Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis isolated in 1994 and 1995

The incidence of pathogenic bacteria in respiratory tract infections in 1994 and 1995 was investigated using quantitative cultures of sputa from patients with the infections in our department. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis were isolated at high rates (70.5% in 1994 and 73.8% in 1995) from the specimens of out-patients, and the incident rates were similar to the past data. The antimicrobial susceptibilities of these three pathogens were examined with the agar dilution method. The incidence of penicillin (Pc) resistant S. pneumoniae against which MIC of Pc-G was higher than 0.125 microgram/ml was markedly increased from 24% in 1994 to 34.9% in 1995. Most of the Pc resistant isolates were also resistant to other antibiotics including erythromycin, minocycline and tosufloxacin. Serotype of strains against which MIC of Pc-G was higher than 1.0 microgram/ml was 19. The ratios of beta-lactamase-producing strains among H. influenzae isolated in 1994 and 1995 were 20 and 15.8%, respectively, which were slightly higher than those in the past. One quinolone resistant strain was isolated in this study. Although the ratio of beta-lactamase-producing strains among M. catarrhalis was as high (96.7%) as in the past, no increased resistance against the drugs examined was observed.     

Criterion-related diagnostic validity and test-retest reliability of the MMPI-168(L) in mentally retarded adolescents and adults

The purpose of this study was to investigate the association of serum antibody levels to Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis with age, gender and smoking in an elderly population. The study population comprised all the inhabitants aged 65 years or over in a rural municipality in south-western Finland. Serum samples were obtained from 1,174 out of a total of 1,360 subjects. Bacterial antibodies were measured by enzyme immunoassay (EIA) using pneumolysin and whole bacterial cells of H. influenzae and M. catarrhalis (mixture of 10 different strains for both) as antigens. The main findings were as follows: (i) antibody levels generally decreased with increasing age both in men and in women; (ii) antibody titres against H. influenzae and M. catarrhalis were higher in men than in women; and (iii) antibody titres to H. influenzae and M. catarrhalis, but not to S. pneumoniae, were significantly higher in smokers than in non-smokers. These data suggest that antibody-mediated protection against respiratory pathogens may be impaired in the elderly, leading to a higher susceptibility to respiratory tract infections, that the exposure to H. influenzae and M. catarrhalis may be higher in men than in women, and that smokers have more respiratory infections or colonization due to these 2 bacteria than do non-smokers.     

In vitro and in vivo antibacterial activities of Q-35, a novel fluoroquinolone

Q-35, a new fluoroquinolone, was evaluated for its in vitro and in vivo antibacterial activities. In vitro antibacterial activity against gram-positive bacteria was almost equal to that of sparfloxacin or tosufloxacin, but its activity against gram-negative bacteria was 2 times or more lower than that of other quinolones tested. In experimental septicemia, the in vivo activity of Q-35 reflected its in vitro antibacterial activity. In respiratory tract infections with Streptococcus pneumoniae TMS-3 in mice, Q-35 showed a therapeutic effect similar to sparfloxacin and tosufloxacin. Q-35 showed almost the same activity as that of ofloxacin in mice with pyelonephritic infection due to Escherichia coli TMS-3. The peak levels of Q-35 in murine serum, lungs and kidneys after a single oral administration were intermediate compared to those of tested quinolones.     

Comparative antimicrobial activity of RP 59,500 (quinupristin-dalfopristin), the first semisynthetic injectable streptgramin, against gram-positive cocci and other recent clinical pathogens

RP 59,500 (Quinupristin-Dalfopristin) is the first semisynthetic injectable streptogramin antimicrobial agent, which is a combination of quinupristin and dalfopristin in a 30:70 ratio. The components of RP 59,500 act synergically to provide bactericidal activity through action at different sites on bacterial ribosomes. In the present study, the antimicrobial activity of RP 59,500 was compared with those of four macrolides (erythromycin, clarithromycin, azithromycin, roxithromycin). Susceptibility testing was carried out by microdilution method on 303 strains of 10 species, especially antibiotic-resistant Gram-positive cocci. RP 59,500 was active against a wide range of Gram-positive cocci including methicillin-resistant Staphylococci and penicillin-resistant Streptococcus pneumoniae. The MICs90 of RP 59,500 against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis were both 0.25 microgram/ml, although those of four macrolides were higher than 32 micrograms/ml. The MICs90 of RP 59,500 against penicillin-sensitive, -intermediate and -resistant S. pneumoniae were all 0.5 microgram/ml, although those of four macrolides against penicillin-resistant S. pneumoniae were higher than 32 micrograms/ml. RP 59,500 also exhibited equivalent activities to the four macrolides against strains of Streptococcus pyogenes. Streptococcus agalactiae and Moraxella catarrhalis. RP 59,500 exhibited the highest activities against Enterococcus faecalis, Enterococcus faecium and Enterococcus avium strains which are intrinsically resistant to most antimicrobial agents. No cross-resistance was observed between RP 59,500 and the four macrolides, which will merit attention in future clinical trials of the agent. The effect of human serum on the MIC of RP 59,500 was studied with strains of S. aureus, S. epidermidis and E. faecalis. The presence of 20% (V/V) serum had little or no effect on the MIC, although 50% (V/V) serum increased MICs by 4-8 folds. Laboratory-induced resistance to RP 59,500 occurred in a stepwise fashion in broth cultures of S. aureus, S. epidermidis and E. facalis strains and the induction rate was slow and no more than four fold increases were observed. Population analysis was performed on RP 59,500 and the reference macrolides against S. aureus ATCC 25,923 strain. Although low frequencies (less than 0.01%) of resistant sub-population were detected with EM, CAM, AZM and RXM, no RP 59,500-resistant sub-population was detected in this study.     

Clinical and bacteriological studies on panipenem/betamipron in pediatrics. Kanagawa Research Group for Infectious Diseases of Children

Following its introduction into the market, PAPM/BP (panipenem/betamipron) was clinically studied in 188 evaluable cases out of 207 cases primarily of respiratory infectious diseases treated at the pediatric departments of 15 hospitals. In the clinical evaluation, the drug proved effective in three of three cases of sepsis; three of three cases of suppurative meningitis; nine of ten cases of laryngopharyngitis, six of seven cases of tonsillitis, 56 of 63 cases of acute bronchitis, 90 of 98 cases of pneumonia, and one of one case of phyothorax, all of which are respiratory infectious diseases; one of one case of secondary infection of a chronic respiratory disease; and two of two cases of lymphadenitis, which is a disease of the soft dermal structure. The overall efficacy rate was 91.0% (171/188 cases). In the bacteriological study, Gram-positive bacteria were eliminated in five of five strains of S. aureus, 30 of 31 strains of S. pneumoniae (96.8%), and three of three strains of S. pyogenes. Gramnegative bacteria were eliminated in 15 of 17 strains of H. influenzae (88.2%), three of four strains of M. catarrhalis, and two of two strains of K. pneumoniae. The overall elimination rate was 92.1% (70/76 strains). In the 23 strains of S. pneumoniae that were examined, penicillin-resistant strains accounted for 56.5%, showing an elimination rate of 100%. No serious adverse effects were observed, and the incidence of adverse effects was 1.45%. As for abnormalities in laboratory tests, levels of GOT and GPT increased in eight cases (3.88%), LDH increased in one case (0.48%), and neutropenia occurred in one case (0.51%). These results suggest that PAMP/BP could be considered the first choice in the treatment of infectious diseases in pediatrics, due to its effectiveness and high level of safety.     

Azithromycin. A review of its use in paediatric infectious diseases

Azithromycin is an azalide antimicrobial agent active in vitro against major pathogens responsible for infections of the respiratory tract, skin and soft tissues in children. Pathogens that are generally susceptible to azithromycin include Haemophilus influenzae (including ampicillin-resistant strains), Moraxella catarrhalis, Chlamydia pneumoniae, Chlamydia trachomatis, Mycoplasma pneumoniae, Legionella spp., Streptococcus pyogenes and Streptococcus agalactiae. Azithromycin is also generally active against erythromycin- and penicillin-susceptible Streptococcus pneumoniae and methicillin-susceptible Staphylococcus aureus. Azithromycin is administered once daily, achieves clinically relevant concentrations at sites of infection, is slowly eliminated from the body and has few drug interactions. In children, azithromycin is usually given as either a 3-day course of 10 mg/kg/day or a 5-day course with 10 mg/kg on the first day, followed by 5 mg/kg/day for a further 4 days. These standard regimens were as effective as amoxicillin/clavulanic acid, clarithromycin, cefaclor and amoxicillin in the treatment of children with otitis media. Azithromycin was also as effective as either phenoxymethylpenicillin (penicillin V), erythromycin, clarithromycin or cefaclor against streptococcal pharyngitis or tonsillitis in children, but appears to result in more recurrence of infection than phenoxymethylpenicillin in this indication, necessitating a dosage of 12 mg/kg/day for 5 days. Community-acquired pneumonia, bronchitis and other respiratory tract infections in children responded as well to azithromycin as to amoxicillin/clavulanic acid, cefaclor, erythromycin or josamycin. Azithromycin was similar or superior to ceftibuten in mixed general practice populations of patients. However, symptoms of lower respiratory tract infections resolved more rapidly with azithromycin than with erythromycin, josamycin or cefaclor. Skin and soft tissue infections responded as well to azithromycin as to cefaclor, dicloxacillin or flucloxacillin, and oral azithromycin was as effective as ocular tetracycline in treating trachoma. Although not as well tolerated as phenoxymethylpenicillin in the treatment of streptococcal pharyngitis, azithromycin is at least as well tolerated as most other agents used to treat respiratory tract and other infections in children and was better tolerated than amoxicillin/clavulanic acid. Adverse events that do occur are mostly gastrointestinal and tend to be mild to moderate in severity. CONCLUSIONS: Azithromycin is an effective and well tolerated alternative to first-line agents in the treatment of respiratory tract, skin and soft tissue infections in children, offerring the convenience of a short, once-daily regimen.     

In vitro and in vivo antibacterial activities of CS-834, a novel oral carbapenem

CS-834 is a novel oral carbapenem antibiotic. This compound is an ester-type prodrug of the active metabolite R-95867. The antibacterial activity of R-95867 was tested against 1,323 clinical isolates of 35 species and was compared with those of oral cephems, i.e., cefteram, cefpodoxime, cefdinir, and cefditoren, and that of a parenteral carbapenem, imipenem. R-95867 exhibited a broad spectrum of activity covering both gram-positive and -negative aerobes and anaerobes. Its activity was superior to those of the other compounds tested against most of the bacterial species tested. R-95867 showed potent antibacterial activity against clinically significant pathogens: methicillin-susceptible Staphylococcus aureus including ofloxacin-resistant strains, Streptococcus pneumoniae including penicillin-resistant strains, Clostridium perfringens, Neisseria spp., Moraxella catarrhalis, most members of the family Enterobacteriaceae, and Haemophilus influenzae (MIC at which 90% of strains are inhibited, < or =0.006 to 0.78 microg/ml). R-95867 was quite stable to hydrolysis by most of the beta-lactamases tested except the metallo-beta-lactamases from Stenotrophomonas maltophilia and Bacteroides fragilis. R-95867 showed potent bactericidal activity against S. aureus and Escherichia coli. Penicillin-binding proteins 1 and 4 of S. aureus and 1Bs, 2, 3, and 4 of E. coli had high affinities for R-95867. The in vivo efficacy of CS-834 was evaluated in murine systemic infections caused by 16 strains of gram-positive and -negative pathogens. The efficacy of CS-834 was in many cases superior to those of cefteram pivoxil, cefpodoxime proxetil, cefdinir, and cefditoren pivoxil, especially against infections caused by S. aureus, penicillin-resistant S. pneumoniae, E. coli, Citrobacter freundii, and Proteus vulgaris. Among the drugs tested, CS-834 showed the highest efficacy against experimental pneumonia in mice caused by penicillin-resistant S. pneumoniae.     

In vitro antimicrobial activities of lactoferrin, its concomitant use with cefpodoxime proxetil and clinical effect of cefpodoxime proxetil

As one of the biodefense mechanisms, lactoferrin (LFN) in the secreta of female genital organ may be an interesting biological material in view of its antimicrobial activity. In the present study, we investigated antimicrobial activities of LFN and its combination with cefpodoxime proxetil (CPDX-PR), we also as evaluated clinical effect of CPDX-PR. The following results were obtained. 1. Antimicrobial activities of LFN were tested against 15 strains of 10 species of bacteria, and potent activities against Staphylococcus aureus 209P, Escherichia coli, Klebsiella pneumoniae and Proteus spp. were found. 2. In a concomitant use of LFN with CPDX-PR (a checkerboard method), synergistic actions were observed against S. aureus 209P, E. coli STf, K. pneumoniae 602 and Pseudomonas aeruginosa 1046, and additive actions against E. coli NIHJ and Providencia rettgeri 1603. In 3 strains, the MICs of CPDX-PR in the presence of LFN were reduced to < 1/64. 3. In the evaluation of clinical effect of CPDX-PR, efficacy rates were 53/57 (92.9%) in a patient group with infections. The incidence of adverse reaction was 0/57.