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PubMedDate not supplied

[Determination of 3,4-dioxyphenyl-L-alanine by spectrophotometric and chromatographic methods in enzymatic synthesis using microbial cells].

A possibility of using the ninhydrin reaction for 3,4-dihydroxyphenyl-L-alanine (DOPA) determining during the synthesis from pyrocatechol and ammonium pyruvate was verified by using free and immobilized cells of Citrobacter freundii, st. 62. Spectrophotometric assay was performed at the adsorption maximum for the DOPA-ninhydrin complex at 390 nm. DOPA can be reliably quantified in the presence of all components at 20-fold and greater dilution of the reaction mixture. A high-sensitive quantitative assay of the reaction mixture was developed based on phase-reversed HPLC. A quantitative correlation was observed between spectrophotometric and chromatographic assays. The assays were employed to study in detail the initial period and equilibrium of DOPA synthesis and its characteristic features, which made it possible to construct a kinetic model of the process.

Catechols↗
PubMed1989

[Activity of 5 fluoroquinolones on hospital Gram-negative bacilli with different sensitivities to pefloxacin].

The minimum inhibitory concentrations (MIC) of 5 fluoroquinolones, fleroxacin (FLE), ciprofloxacin (CIP), ofloxacin (OFL), enoxacin (ENO) and norfloxacin (NOR) have been determined by the agar dilution method towards 140 strains of Pseudomonas aeruginosa (Pa) and 146 Enterobacteriaceae showing different sensitivities to pefloxacin (PEF). The strains were isolated in 1988 at the Bellevue Hospital. The modal MIC is 0.12 for CIP, 0.25 for NOR, 0.5 for OFL, and 1 for FLE and ENO when used on Pa strains which are sensitive to PEF (n = 35) (MIC less than or equal to 1mg/1). The modal MIC is 0.25 - 0.5 for CIP, 0.5 for NOR, 1 for OFL and ENO, and 2 for FLE when used on Pa strains which are of intermediate sensitivity to PEF (n = 70) (1 less than MIC less than or equal to 4). The modal MIC is 2 for CIP, 8 for NOR and OFL, 8 - 16 for ENO, and 32 for FLE when used on Pa strains which are resistant to PEF (n = 35) (MIC greater than 4). The modal MIC is 0.015 for CIP, 0.06 for OFL, 0.12 for FLE, NOR and ENO when used on Escherichia coli strains which are sensitive to PEF (n = 47). The modal MIC is 0.5 for CIP, 1 for OFL and NOR, and 2 FLE and ENO, when used on Escherichia coli strains which are of intermediate sensitivity to PEF (n = 38). The modal MIC is 1 for CIP, 4 for OFL and NOR, 16 for FLE, and 32 for ENO when used on E coli strains which are resistant to PEF (n = 15). The 26 Serratia marcescens and 20 Citrobacter with MIC greater than or equal to 8 for PEF all have MICs greater than 1 and modal MICs greater than or equal to 4 for all the fluoroquinolones studied. CIP always showed greater activity than the other quinolones whatever the sensitivity shown towards PEF.

Anti-Infective Agents↗
PubMed1989

[Acute necrotizing cholecystitis in infancy: report of a case].

We present a case-report of a six weeks old premature baby who developed acute acalculous gangrenous cholecystitis related to septicemia due to Citrobacter freundii. We analyze other etiological factors and remark the importance of physical examination and ultrasonographic exploration of the biliary tract. Early cholecystectomy is suggested.

Acute Disease↗
PubMed1989

Studies on the microflora associated with xenic cultures of Entamoeba gingivalis.

The microflora associated with xenic stock cultures (ATCC 30927) of Entamoeba gingivalis, the major protozoan of the human oral cavity, were isolated and identified as Citrobacter diversus, Yersinia enterocolitica, Acinetobacter anitratus and Pseudomonas maltophilia. In studies to determine whether the bacterial isolates were able to utilize rice starch as a sole carbon source, Y. enterocolitica exhibited excellent growth in rice starch minimal medium and TYSGM-9 medium (with rice starch), but growth was weak in TYSGM-9 medium (without rice starch). C. diversus, A. anitratus and P. maltophilia exhibited poor growth in rice starch minimal medium, but they produced excellent growth in TYSGM-9 medium with or without rice starch. In order to determine the effect of the rice starch hydrolysis on Entamoeba growth, the filtrate from each isolate grown in rice starch minimal medium was added to an E. gingivalis culture grown in TYSGM-9 medium. The filtrate from a Y. enterocolitica culture grown in rice starch minimal medium enhanced E. gingivalis growth, but the filtrates from cultures of C. diversus, A. anitratus and P. maltophilia suppressed E. gingivalis growth. This supported the concept that Y. enterocolitica is capable of metabolizing rice starch into intermediate products, which in turn can be utilized by the amoeba.

Acinetobacter↗
PubMedDate not supplied

[Effect of silver preparations on the microflora regenerated from a condensate of atmospheric water vapor in a hermetically-sealed chamber].

The effect of different silver compounds (silver sulphate, silver nitrate, electrolytic ionic silver) on microorganisms in water reclaimed from the atmospheric condensate in an enclosed environment was investigated. The following microorganisms were examined: Alcaligenes faecalis, Citrobacter freundii. Aeromonas hydrophila, Staphylococcus epidermidis, etc. The ionic silver concentrations in solution varied from 0.1 to 10 mg/l. The efficiency of the silver compounds was found to depend on the microbial strain, ionic silver concentration in solution, and time of exposure. The microflora of the reclaimed water proved to be highly resistant to the preservatives which was strongly associated with the bacterial physical and chemical composition of the products preserved.

Aeromonas↗
PubMed1986

In vitro activity of ciprofloxacin compared with other agents against recent hospital isolates.

Ciprofloxacin's in vitro activity was tested against 385 hospital isolates originating from three geographically distinct regions. Of all strains tested, only three (1 Acinetobacter sp. and 2 Pseudomonas aeruginosa) were ciprofloxacin resistant. Ciprofloxacin was more active against Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Acinetobacter sp., Proteus sp., Shigella sp. than gentamicin, mezlocillin and cefotaxime. It was more active than azlocillin and cefsulodin against P. aeruginosa. It was more active than cloxacillin and cefamandole against staphylococci. It was as active as cefotaxime against Klebsiella pneumoniae, Citrobacter freundii and Serratia marcescens. Ciprofloxacin demonstrated similar activity in broth and solid agar. The minimal inhibitory concentrations (MIC's) of all strains were similar to the minimal bactericidal concentrations (MBC's). Ciprofloxacin's MIC was not influenced by increase of the inoculum or addition of human serum and only slightly influenced by anaerobic conditions. Decrease of the medium pH increased the MIC substantially. Ciprofloxacin exhibited a rapid bactericidal effect and had only a minimal post-antibiotic effect. These favorable in vitro characteristics of ciprofloxacin warrant further studies.

Acinetobacter↗
PubMed1988

[Isolation and characterization of gentamicin resistance plasmids of coliform bacteria from the waste water of a water treatment plant].

Gentamicin resistance coliforms detected continuously in raw and purified waste water samples of a sewage treatment plant made up less than 0.1% of all coliforms. 43.9%; 31.4%; 13.3% and 11.3% of gentamicin-resistant coliforms were identified as Enterobacter, E. coli, Klebsiella and Citrobacter, respectively. R plasmids encoding a gentamicin resistance phenotype were isolated and characterized. They range between 55 and 60 MD in size and belong to 3 incompatibility groups (IncOF, IncM, IncK). Using restriction endonucleolytic digestion of plasmids, they could be further characterized and subtyped. In contrast to moderate molecular alterations observed among the IncM plasmids, the IncOF plasmids reveal a high stability of restriction pattern. This IncOF plasmid was predominantly found in E. coli wild strains and detected continuously.

Citrobacter↗
PubMed1988

[Microbiological analysis of well water samples in the rural areas near Ankara].

The water from wells and running water in different rural parts of Ankara were analyzed microbiologically with the thought in mind that the use of unhealthy well water could cause infections, as shown in other cities. We found that of the 50 running water samples all (100%) were drinkable from the microbiological point of view regard to coliform bacteria and total germ count, while only 20 of the 150 well water samples (13.3%) met these standards. It was pointed out by the users that chlorination was carried out in only 22 of the wells (14.6%) and only irregularly; no coliform bacteria were found in water samples from these wells. In 117 well water samples (78%) 120 coliform bacteria strains were isolated, of these 80 were E. coli, 27 Enterobacter and 13 Citrobacter. All samples were analyzed for Giardia intestinalis cysts but found to be negative.

Bacteria↗
PubMed1986

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

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

Anti-Bacterial Agents↗
PubMed1987

[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.

Aztreonam↗
PubMed1987

In vitro susceptibility of nosocomial Pseudomonas aeruginosa, enterobacteriaceae, and staphylococci to ciprofloxacin and ten other broad-spectrum antibiotics.

We determined microdilution minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for ciprofloxacin and 10 beta-lactam and aminoglycoside antibiotics against 329 unique nosocomial isolates of Pseudomonas aeruginosa, citrobacter, enterobacter, serratia, and staphylococci. All were susceptible to ciprofloxacin, including 109 aminoglycoside-resistant gram-negative bacilli and 59 oxacillin-resistant staphylococci. Ciprofloxacin was generally 2-4 fold less active against aminoglycoside-resistant isolates than against their aminoglycoside-susceptible counterparts.

Aminoglycosides↗
PubMed1977

[Enterobacteria erroneously identified as Salmonella in human faeces (author's transl)].

To differentiate Citrobacter freundii, Enterobacter hafniae, Proteus mirabilis and Alteromonas putrefaciens from Salmonella strains isolated in faeces, the author recommends the use of "Hajna-Kligler" medium, "Nitrate-Motility-Mannitol" medium, "Urease-Indole-Trytophane desaminase" medium and glycerol peptonated water. The lysis of Salmonella and E. hafniae strains by specific phages (Felix and Callow O: 1 Salmonella phage; Guinee and Valkenburg Hafnia phage) is emphasized.

Bacteriophage Typing↗
PubMed1977

[Study of the role of conditionally pathogenic enterobacteria in acute intestinal diseases].

Conditionally pathogenic enterobacteria were isolated in 34.2% of the patients with acute intestinal diseases (1559 cases examined in all). Such representatives of enterobacteria as Klebsiella, Hafnia, Citrobacter of 4, 8, and 22 serological groups. Proteus mirabilis of 6, 10, 13, 26, and 28 serological groups, and Proteus morganii mostly played the etiological role. In some of the patients conditionally pathogenic microbes only aggravated the main disease, taking part in the development of dysbacteriosis. In healthy individuals these microbes were much more rare and were encountered inconstantly.

Acute Disease↗
PubMed1977

[R-factor distribution and characteristics of the E. coli isolated from pigs].

Studied was the occurrence of the R-factors in Escherichia coli isolated from pigs. It was demonstrated that in 73.3 per cent of the cases drug resistance could be transmitted to Citrobacter. In this instance an occasional drop-out of the markers of resistance to kanamycin, neomycin, ampicillin, tetracycline, and chloramphenicol was observed. In the author's experiments no transmission of the marker of resistance to furazolidon was established. The transmission of the signs of resistance to kanamycin and niomycin as well as to erythromycin and oleandomycin occurred always simultaneously. The possibility of transmitting the drug resistance markers of Escherichia coli to Salmonella typhimurium LT-2 made it reasonable to believe that this is one of the routes for spreading the R-factors among Salmonella organisms. No essential differences were observed between the minimal inhibitory concentration of the donor strains and the level of the acquired resistance with the recombinations. The transmission frequence of the resistance markers proved comparatively high, and ranged from 0.6.10(-3) up to 3.10(-4).

Animals↗
PubMed1977

[Coliform bacteria in raw and pasteurized milk].

Studied were 360 samples of raw and 1404 samples of pasteurized milk, collected from three milk centers, for the presence of coliform bacteria. It was found that the coli titer of the raw milk varied from 10(-5) up to 10(-7), depending on the season. The regimes of pasteurization applied kill 100 per cent of the present coli organisms. After the thermic treatment the milk was additionally contaminated with coli forms from the containers and the equipment in dependence on the conditions of washing and disinfection. The coli titer of the pasteurized milk varied from 1 to 10(-3). A total of 602 strains of coliform bacteria were isolated from the pasteurized and the raw milk; the bacteria were differentiated by the scheme of Kauffmann. Most commonly encountered were the coli forms of the following genera:Citrobacter (35 per cent), Enterobacter (29.8 per cent), Klebsiella (23.9 per cent), and Escherichia (11.3 per cent). The following species were prevailing in raw milk: Kl. aerogenes, Ent. aerogenes, Ent. cloacae, C. freundi, and C. intermedium. In pasteurized milk dominating were Kl. aerogenes, C. freundi. Ent. aerogenes, and Ent. cloacae.

Animals↗
PubMed1979

Gentamicin resistance in Christchurch hospitals.

Prior to June 1976, the isolation of gentamicin resistant organisms was an infrequent occurrence in North Canterbury Hospital Board institutions. During July 1976, 20 different gentamicin resistant organisms were isolated from patients in Christchurch Hospital. Gentamicin resistant organisms hav e been continually isolated from an increasingly wide area since then. The organisms involved are: providence species; Pseudomonas aeruginosa; Klebsiella species; E coli; Staphyloccus aureus; Proteus mirabilis; Staphylococcus epidermidis; Acinetobacter species; Enterobacter species; Haemophilus influenzae; Pseudomonas maltophilia CDC II F; Citrobacter species; Alcaligenes odorans and Pseudomonas species. The spread of gentamicin resistant organisms has occurred rapidly in the hospital environment. The importance of the urinary tract as a reservoir of microorganisms is indicated in this report.

Acinetobacter↗
PubMed1985

[Distribution and changes in the susceptibility of bacteria isolated from clinical samples. III].

This report presents data concerning in vitro activity of antimicrobial agents against Citrobacter freundii, Enterobacter spp., Serratia marcescens and Proteus vulgaris isolated from patients with complicated urinary tract infections and against Pseudomonas aeruginosa isolated from surgical wounds with postoperative infection and exudate from superficial abscesses. There was a marked increase of resistant strains of C. freundii, Enterobacter spp. and S. marcescens to penicillins, CEPs or GM. The isolates of these species obtained in 1983 showed MIC values of 100 micrograms/ml or more for the so-called new CEPs (CTX, CMX, CZX, LMOX and CPZ). The P. vulgaris isolates exhibited an increasing incidence of strains resistant to penicillins, and data on P. vulgaris isolates in 1983 indicated increase of strains resistant to CEPs. GM-resistant organisms were also noted to be increasing among the isolate of this species. The analysis did not reveal any appreciable change with calendar years among P. aeruginosa in respect of frequency of strains resistant to SBPC or CEPs (except CPZ). The data obtained in 1983, however, showed an indication of increasing incidence of organisms resistant to CPZ and GM. The increasing tendency of emergence of organisms resistant to new CEPs designed to expand activity against C. freundii, Enterobacter spp., S. marcescens and P. vulgaris, observed among the isolates of these species is considered probably to be the consequence of bacterial selective acquisition of R plasmid that carry drug resistant genes against CEPs. These are exactly reflected in the present data obtained in studies initiated in 1981 when the new CEPs became commonly prescribed in the daily clinics. It is concluded, accordingly, that organisms of these species resistant to CEPs have been increasing throughout the country.

Anti-Bacterial Agents↗
PubMed1985

[In vitro effect of ceftriaxone on hospital bacteria. Line of regression and critical values].

Antimicrobial activity of ceftriaxone, a new third generation cephalosporin, against hospital isolates was investigated. 312 strains belonging to the most commonly recovered species were studied using the following methods: agar diffusion (disk antibiotic testing), agar dilution (determination of MIC) and dilution in a liquid medium with subculture to agar plates (determination of MBC). Except for a few Citrobacter strains and rare Serratia strains, all Enterobacteriaceae tested proved highly susceptible, with MICs less than or equal to 1 mg/l and mode MICs ranging from 0.003 mg/l (Proteus) to 0.25 mg/l (Enterobacter). MICs ranged from 16 to 32 mg/l for Acinetobacter (mode MICs: 16 mg/l) and 16 to greater than or equal to 128 for Pseudomonas (mode MIC greater than or equal to 128 mg/l). Methicillin-susceptible staphylococci were moderately susceptible to ceftriaxone (MIC: 2 to 8 mg/l) whereas methicillin-resistant staphylococci and enterococci were resistant (MIC greater than or equal to 64 mg/l). Bactericidal activity was excellent: MBC/MIC less than or equal to 2 (except for a few Serratia strains). A correlation curve was established. Given the high serum concentrations of ceftriaxone (achieved with the usual maximal dosage) and its unusually extended half-life (7 to 8 h), the following cutoff concentrations can be proposed: C less than or equal to 4 mg/l, corresponding to greater than or equal to 20 mm: susceptible bacteria C greater than 32 mg/l, corresponding to less than 15 mm: resistant bacteria.

Acinetobacter↗