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PubMed1985

[HR 810 (cefpirome). Experimental evaluation of the in vitro and in vivo antibiotic activity of a new amino-2-thiazole methoxy- imino cephalosporin].

HR 810 or cefpirome is a new amino thiazole cephalosporin whose specific characteristic is a cyclopentenopyridinium group in position 3 of the cephem nucleus. This structure is responsible for a broad spectrum of activity, covering Enterobacteriaceae, including cephalosporinase-producing Enterobacter spp. and Citrobacter spp., Staphylococcus aureus, Pseudomonas aeruginosa and group D Streptococci.

Animals↗
PubMed1979

Resistance of gram-negative bacteria to antibiotics in large calf agglomerations.

The antibiotic resistance of E. coli, Citrobacter, Enterobacter-Klebsiella and Pseudomonas aeruginosa strains isolated from calves was tested. A high proportion of multiresistance was found even in E. coli strains isolated from newborn calves. Gram-negative bacteria isolated from animals in three large calfhouses were almost 100% resistant to ampicillin, tetracyclines and sulphonamides. Multiresistance was general and varied from 5 to 12 antibiotics among different strains. Initial high sensitivity to antibiotics which had never been used before was observed. Antibiotic resistance rapidly increased after use started. The usefulness of antibiotics in E. coli induced diarrhea is questioned and oral rehydration is appraised.

Animals↗
PubMed1976

[Gentamicin-susceptibility of various pathogens isolated from clinical materials].

We studied on the antibacterial activity of gentamicin against various pathogens isolated from clinical materials mainly isolated during 1974 and 1975, comparing with other antibiotics. Beta hemolytic streptococci, pneumococci and enterococci are less susceptible to gentamicin than staphylococci. Staph, aureus and Staph. epidermidis resistant to various antibiotics are very susceptible to gentamicin, and no resistant strain to this drug was found. Haemophilus influenzae, H. parainfluenzae and H. parahaemolyticus are very susceptible to gentamicin, and there is no resistant strain to this drug. Escherichia coli, Klebsiella, Citrobacter, Serratia and five species of Proteus are more susceptible to gentamicin and tobramycin than dibekacin and amikacin. A few resistant or less susceptible strains to gentamicin are found in E. coli, Citrobacerr, Serratia, Pr. morganii and Pr. rettgeri. Pr. inconstans is less susceptible to gentamicin than other species of Proteus. Antibacterial activity of gentamicin against Pseudomonas aeruginosa is very strong, but dibekacin and tobramycin are stronger. Gentamicin-resistant strains of Pseudomonas aeruginosa are now rather few.

Citrobacter↗
PubMedDate not supplied

[Specificity of new restrictases and methylases. Unusual modification of cytosine at position 4].

Fourteen restriction endonucleases and 4 methylases were isolated and purified from 14 strains of Citrobacter freundii and Escherichia coli, which were isolated from natural sources. To determine the nucleotide sequence recognized by the endonucleases a comparison of DNA cleavage patterns, the evaluation of the cleavage frequency of some DNA with known recognition sequences and mapping was used. It was determined that Cfr101 is a new enzyme recognizing 5'PuCCGGPy. Other restriction enzymes isolated were isoschizomers of: Cfr5I, Cfr11I, Eco60I, Eco61I--EcoRII; Cfr4I, Cfr8I, Cfr13I--Sau96I; Cfr6I--PvuII, Cfr9I--SmaI, Eco26I--HgiJII; Eco32I--EcoRV; Eco52I--XmaIII; Eco56I--NaeI. Some of the enzymes in C. freundii and E. coli were found for the first time. The methylases MCfrI; MCfr6I, MCfr9I and MCfr10I recognize the same nucleotide sequence as specific endonucleases isolated from the same strain. DNA modification in vitro by MCfrI and MCfr10I yields 5-methylcytosine and 4-methylcytosine by MCfr6I and MCfr9I.

Adenoviridae↗
PubMed1984

Bacterial changes in the urine samples of patients with long-term indwelling catheters.

The bacterial flora in the urine samples of 15 nursing home patients with long-term, indwelling catheters were examined monthly for one year. There was a rapidly changing polymicrobial flora averaging 2.0 changes per month in species with colony counts greater than 100,000/mL, and 3.2 changes per month when changes in species, biogram, and quantity of bacteria were considered. The flora changed significantly more frequently, and cultures of Pseudomonas aeruginosa, Providencia stuartii, and Citrobacter diversus were significantly more frequent in those receiving sulfamethoxazole and trimethoprim prophylaxis than in those who did not. There was no difference in incidence of urinary tract infection (UTI) between those patients who received sulfamethoxazole and trimethoprim prophylaxis and those who did not. Ampicillin or gentamicin was effective against 99% of species cultured that are of established UTI pathogenicity. Owing to the rapidity of bacterial flora changes, routine monthly cultures are of little predictive value in patients with indwelling catheters. This study does not support the efficacy of sulfamethoxazole and trimethoprim prophylaxis in such patients.

Adult↗
PubMed1983

Influence of methoxy-substitution of beta-lactam compounds on the interaction with various beta-lactamases.

The interaction of 6 alpha-(temocillin) and 7 alpha-methoxy substituted (cefoxitin) beta-lactam compounds with various beta-lactamases was studied employing enzyme kinetics and compared to that of unsubstituted compounds. Both chromosomally mediated enzymes from Enterobacter cloacae and Citrobacter freundii were competitively inhibited by the methoxy-substituted compounds. Higher concentrations of cefoxitin caused a competitive inhibition of the plasmid-mediated Tem-1 enzyme, whereas temocillin led to a non-competitive inhibition of the Tem-1 enzyme. These results indicate that the discrepancies in the interaction on the above mentioned compounds have to be attributed to the different molecular structure of the beta-lactam nucleus. Moreover, no predictions can be made on the basis of an analogy between 6 alpha-methoxy-penams and 7 alpha-methoxy cephems.

Binding, Competitive↗
PubMed1983

Investigations on beta-lactamase stability of recently developed beta-lactam compounds: study of enzyme kinetics.

The plasmid-mediated TEM-1 enzyme (E. coli K12 R6K) and chromosomally mediated enzymes from Enterobacter cloacae (IEP 8.5) and Citrobacter freundii (IEP 9.5) were highly purified. Enzyme kinetics were studied with various therapeutic compounds as substrates and lamoxactam, azthreonam, and N-formimidoyl thienamycin as inhibitors. Lamoxactam and azthreonam failed to inhibit the TEM-1 enzyme, whereas N-formimidoyl thienamycin was a competitive inhibitor. KI was 5 mumol/l--thus corresponding to KM--and independent of the substrate. With respect to chromosomally mediated enzymes, there was a time-dependent inhibition of beta-lactam hydrolysis. KI ranged from 0.06 to 0.2 mumol/l in dependence of the inhibitor. Enzyme kinetics suggested a non-competitive type of inhibition thus indicating that binding of these compounds to both chromosomally mediated enzymes must be followed by a further reaction step. It is evident that the stability against beta-lactamases of recently developed compounds is based on different mechanisms--characteristic for the enzyme being considered.

Anti-Bacterial Agents↗
PubMed1980

[Method of isolating conditionally-pathogenic Gram-negative microorganisms, agents of intrahospital infections, from air].

The possibility of detecting Pseudomonas aeruginosa and other Gram-negative bacteria in the air of the burn department at the Institute of Surgery was studied. The investigation of large volumes of air (0.5-1 m3) in the wards and the corridor with the use of a new bacteriological aerosol sampler, model IIAB-5, resulted in the detection of Pseudomonas aeruginosa. Besides, in a number of other rooms Klebsiella, Proteus, Citrobacter and Enterobacter were detected in the air. The possibility of the spread of Gram-negative opportunistic bacteria through the air in hospital conditions is discussed.

Air Microbiology↗
PubMed1980

[Quantitative and qualitative characteristics of representatives of the enterobacteriaceae family in postradiation intestinal dysbacteriosis].

The irradiation of CBA mice with gamma quanta in a dose of 700 C/kg resulted in the development of postradiation intestinal dysbacteriosis in the animals. The dysbacteriosis was characterized by a considerable increase in the number of Escherichia and Proteus mirabilis in the large intestine and by the insemination of the small intestine with these microbial associations. Pr. vulgaris, Pr. morganii, Ent. aerogenes, Ent. cloacae, Citrobacter appeared in great numbers in the intestinal tract of the irradiated mice, while none of these organisms were found in the intact mice.

Animals↗
PubMed1981

Relationship of colonic mucosal background to neoplastic proliferative activity in dimethylhydrazine-treated mice.

Proliferative activity of background and neoplastic colonic mucosa was examined following five months of weekly injections of 1,2-dimethylhydrazine (20 mg/kg) and one or four months of rest to determine whether previously reported changes may result from an acute or chronic effect of dimethylhydrazine and whether differences exist between stages of neoplasia. To determine whether neoplasia is responsive to a proliferative stimulus, 1,2-dimethylhydrazine dihydrochloride-treated mice were inoculated with Citrobacter freundii. The labeling index and the proliferative zone increased in background mucosa after one month; whereas after four months labeling index, proliferative zone and crypt heights increased, but the mitotic index decreased. There was a positive linear correlation between advancing tumor grade and increasing tumor labeling index and mitotic index. Background labeling index, even when elevated by C. freundii inoculation, had no effect upon tumor labeling index. Mitotic index diminished in background and neoplastic mucosa following prolonged rest and increased in both following C. freundii inoculation. These studies show that 1,2-dimethylhydrazine dihydrochloride causes long-term changes in background mucosa that are apart from a reparative response to cytotoxicity. As tumors progress, labeling index and mitotic index increase, suggesting a multistage process of evolution.

1,2-Dimethylhydrazine↗
PubMed1980

Modification of early dimethylhydrazine carcinogenesis by colonic mucosal hyperplasia.

The interaction of colonic mucosal hyperplasia with early 1,2-dimethylhydrazine (DMH) carcinogenesis was studied in random-bred NIH Swiss mice utilizing hyperplasia-inducing Citrobacter freundii. Mice inoculated with this bacterium developed significantly more DMH focal atypia than did mice without hyperplasia following a single dose of DMH (20 mg/kg). Mice with hyperplasia also developed DMH focal atypia with diminished doses of DMH (10 and 5 mg/kg), while normal mice did not. The effect of C. freundii on early DMH carcinogenesis was shown to be due to the hyperplasia rather than to a direct interaction of the bacterium with DMH. Focal atypia arose in high incidence 1 month after a single dose of DMH (20 mg/kg) but did not appear to progress to later stages of neoplasia, since significantly fewer atypia were present at 2 to 4 months among a randomized population. Colonic focal atypia may represent a reversible preneoplastic or precursor lesion as seen in other tissues, with features more aligned to neoplasia than to hyperplasia.

Animals↗
PubMed1994

[Analysis of cases with liver abscess following transcatheter arterial chemoembolization (TAE) for malignant hepatic tumors].

A total of 182 TAE procedures were carried out in 98 patients with malignant hepatic tumors during the last five years. Liver abscess following TAE occurred in 3 cases (3.1%) and in 3 procedures (1.7%). All cases were discharged after successful percutaneous transhepatic abscess drainage. One case had hepatocellular carcinoma. Another case had undergone total gastrectomy and esophagojejunostomy with Roux-Y reconstruction for gastric leiomyosarcoma. The other had undergone right hemicolectomy and pancreatoduodenectomy for colon cancers and carcinoma of the ampulla of Vater. Communication between the abscess and the intrahepatic bile duct was recognized in 2 cases. In the abscess culture, E. coli and Citrobacter freundii were detected. These results suggest the major factor leading to abscess formation is biliary infection. Therefore, a previous bilio-enteric anastomosis should be regarded as a risk factor for liver abscess following TAE.

Aged↗
PubMed1994

[Nationwide survey on susceptibilities of clinical isolates from urinary tract to antimicrobial agents in Japan, 1991].

This study was conducted to investigate susceptibilities of urinary tract isolates to antimicrobial agents examined at 123 hospital laboratories in Japan from September to December in 1991. In this study, identification and susceptibility testing were carried out at each laboratory. The susceptibility testing was performed according to the disk diffusion method recommended by National Committee for Clinical Laboratory Standards. MRSA showed high resistance rates to all agents tested except to minocycline (MINO). MSSA had good susceptibility to imipenem (IPM) and cephalosporins with susceptibility rates higher than 90%. Enterococcus faecalis was susceptible to IPM, ampicillin and piperacillin (PIPC) and highly resistant to cephalosporins, gentamicin (GM), erythromycin, clindamycin and MINO. Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were susceptible to beta-lactam drugs, GM and ofloxacin (OFLX). High susceptibility rates were observed for strains of Enterobacter cloacae, Citrobacter freundii to IPM, GM, and OFLX and of Serratia marcescens for IPM and GM. Pseudomonas aeruginosa strains were highly susceptible to IPM, ceftazidime, AMK, cefsulodin, cefoperazone, PIPC in this order.

Anti-Bacterial Agents↗
PubMed1976

[Sensitivity of bacteria causing urinary tract infections towards terizidon (author's transl)].

In agar diffusion tests 2603 bacterial strains of species known to cause urinary tract infections were tested routinely in regard to their sensitivity towards Terizidon, a derivative of cycloserine. In order to relate the results which were obtained in terms of the diameter of the inhibiton zone, to the minimal inhibitory concentrations (MIC), 304 of these strains were tested additionally in agar dilution tests. The MICs of the other strains were estimated from the results of these tests. Since it is known that after the oral administration of 500 mg Terizidon the urine contains, on average, more than 128 mug/ml Terizidon for 12 hours and longer, it may be concluded from the results of this investigation that 75% of the strains of E. coli and Citrobacter, 45% of enterobacter, 40% of Proteus mirabilis and enterococci, 35% of the indole-positive Proteus strains and 30% of Pseudomonas aeruginosa would have been successfully attacked by Terizidon in the case or urinary tract infections. By contrast, Klebsiella must be reagarded as being completely resistant to this antibiotic. It follows that the administration of Terizidon is mainly indicated in the treatment of acute urinary tract infections with E. coli as the predominant causative agent.

Citrobacter↗
PubMedDate not supplied

[Antimicrobical resistance of bacterial strains isolated in specimens of the respiratory tract (author's transl)].

More than 4,000 susceptibility tests of antimicrobical agents performed in two years with six groups of microorganisms: 1) Staphylococcus, 2) Escherichia coli, 3) Proteus, 4) Enterobacter and Klebsiella, 5) Citrobacter, 6) Pseudomonas aeruginosa, have been compared. Percentages of antimicrobical resistance of every group are here related and statistically compared to discover significant susceptibility variations of bacteria isolated in 1973 and 1974.

Anti-Bacterial Agents↗
PubMed1976

[On the growth of various Enterobacteriaceae, Pseudomonas aeruginosa and Alkaligenes spec. in distilled water, de-ionized water, tap water, and mineral salt solution (author's transl)].

The behaviour of 12 strains of gram-negative bacteria was analysed in media having a low content of nutrients. Sterile tap water, de-ionized water, aqua bidestillata and mineral salt solution were used. It was found that Serratia marcescens, Pseudomonas aeruginosa, Enterobacter, Klebsiella and Citrobacter are those with the most frequently observed growth. In the mineral salt solution survived also Providencia, E. coli, Erwinia, Hafnia, and Alkaligenes and reached max. colony numbers of some 100000/ml. When the salts used were added stepwise potassium phosphate and especially magnesium sulfate showed a growth-promoting effect.

Alcaligenes↗
PubMed1993

Role of Ser-238 and Lys-240 in the hydrolysis of third-generation cephalosporins by SHV-type beta-lactamases probed by site-directed mutagenesis and three-dimensional modeling.

A growing number of extended spectrum SHV-type beta-lactamases capable of hydrolyzing third-generation cephalosporins such as cefotaxime and ceftazidime have been reported. These new enzymes differ by a few amino acids from SHV-1, an enzyme incapable of hydrolyzing these drugs. Two of these substitutions, Gly-238-->Ser and Glu-240-->Lys, are in a key beta-strand of the catalytic site of class A beta-lactamases. To understand the structural basis of these new activities, we first subcloned the DNA region coding for SHV-1 and SHV-2 and did site-directed mutagenesis to create two mutant SHV-1 proteins containing Ser and Glu or Gly and Lys and two mutant SHV-2 proteins containing Gly and Glu or Ser and Lys in positions 238 and 240, respectively. Phenotypic analysis (antibiograms and minimum inhibitory concentrations) and activity spectra of mutant enzymes showed that Ser-238 is critical for cefotaxime hydrolysis whereas both Ser-238 and Lys-240 are needed for strong ceftazidime hydrolysis. A three-dimensional model for SHV beta-lactamase complexes was constructed using the crystallographic structure of the homologous Bacillus licheniformis beta-lactamase, the complex of cefotaxime with the Streptomyces sp. R61 D-alanyl-D-alanine peptidase, and the complex of aztreonam with the Citrobacter freundii beta-lactamase. The modeling of SHV beta-lactamase complexes showed that factors which are most likely to correlate with binding and kinetic data are the size of the relatively buried amino acid at position 238 and the electrostatic charge of the exposed group at position 240.

Amino Acid Sequence↗