SEARCH · Search PubMed

Results for “ENTEROBACTERIACEAE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1977

The use of bile - esculin agar for the taxonomic classification of the family Enterobacteriaceae.

Bile-esculin medium has been used for many years for the presumptive identification of group D Streptococcus. The test is based on the ability of a bacterium to grow in the presence of 40% bile and produce esculinase. 2935 strains of Enterobacteriaceae were inoculated onto bile-esculin agar slants and incubated at 35 C. Esculin hydrolysis was determined after 24 and 48 hours. At 24 hours of incubation esculin hydrolysis was limited to the genera Klebsiella, Enterobacter, Serratia, and the species P. vulgaris, P. rettgeri, and C. diversus. Not all strains of these species were positive, however. All other members of the family were negative. At 48 hours of incubation 37% of E. coli gave a positive reaction; all other Enterobacteriaceae which were negative at 24 hours remained negative. Esculin hydrolysis is a valuable test for the taxonomic classification of the family Enterobacteriaceae.

Bacteriological Techniques↗

PubMed2002

The role of conjugative transposons in the Enterobacteriaceae.

Although widely studied in gram-positive Streptococci and in the gram-negative Bacteroides, there is a scarcity of information on the occurrence and nature of conjugative transposon-like elements in the well-studied Enterobacteriaceae. In fact, some of the major reviews on conjugative transposons prior to 1996 failed to mention their occurrence in this group. Recently, their presence has been reported in Salmonella, Vibrio and Proteus species, and in some cases such as the SXT element in Vibrio and the IncJ group element CTnR391, there has been some molecular characterization. The elements thus far examined appear to be larger than the common gram-positive conjugative transposons and to be mosaic in structure, with genes derived from several sources. Recent evidence suggests that in the Enterobacteriaceae the elements may be related to enteric pathogenicity islands. The evolution, distribution and role of these elements in the Enterobacteriaceae is discussed.

Amino Acid Sequence↗

PubMedDate not supplied

Elimination of fecal Enterobacteriaceae by intravenous ciprofloxacin is not inhibited by concomitant sucralfate--a microbiological and pharmacokinetic study in patients.

Intravenously administered ciprofloxacin is partially secreted into the intestinal lumen and thereby eliminates fecal Enterobacteriaceae. Sucralfate inhibits the antimicrobial activity of ciprofloxacin by chelate binding. In a prospective study, we investigated the impact of intravenous ciprofloxacin on the intestinal microflora during oral administration of sucralfate. A total of 45 stool specimens were analyzed in 20 hospitalized patients who were treated with 200 mg of ciprofloxacin i.v. bid. Ten patients concomitantly received 1 g sucralfate p.o. tid (group A). After more than 3 days of i.v. ciprofloxacin, the mean fecal ciprofloxacin concentration was 185.3 +/- 158.7 micrograms/g in patients of group A and 108.7 +/- 76.9 micrograms/g in patients without concurrent sucralfate (group B). There was no significant difference in mean fecal ciprofloxacin levels between both groups (Wilcoxon's test). Enterobacteriaceae were below the threshold of detection (10(2) cfu/g) in all patients of group B after 3 days of treatment whereas small numbers were found in only 2 samples of patients of group A (10(4) cfu/g). Intravenous ciprofloxacin eliminates or largely reduces intestinal Enterobacteriaceae irrespective of concurrent administration of sucralfate.

Administration, Oral↗

PubMedDate not supplied

Ewingella americana gen.nov., sp.nov., a new Enterobacteriaceae isolated from clinical specimens.

We propose the name Ewingella gen.nov. for a new group in the Enterobacteriaceae. Ewingella is phenotypically distinct from all other groups of Enterobacteriaceae. The members of this genus are lipase- and deoxyribonuclease-negative; Voges-Proskauer-positive; lysine-, ornithine- and arginine-decarboxylase-negative; anaerogenic; they produce acid from glucose in the presence (and absence) of iodoacetate, but fail to produce acid from L-arabinose, melibiose, raffinose, D-sorbitol or sucrose. DNA-relatedness studies (S1-nuclease method) showed that the 10 Ewingella strains studied form a single DNA-hybridization group which is less than 21% related to other members of the Enterobacteriaceae. This single DNA-hybridization group is named Ewingella americana sp. nov. The type strain of E. americana is CDC 1468-78 (= ATCC 33852 = CIP 8194). Although the 10 strains of E. americana were isolated from clinical sources in the United States, the clinical significance of these organisms is not known.

Base Composition↗

PubMed2006

Rapid identification of Enterobacteriaceae by sequencing DNA gyrase subunit B encoding gene.

Real-time polymerase chain reaction and sequencing were used to characterize a 506-bp-long DNA fragment internal to the gyrB gene (gyrBint). The sequences obtained from 32 Enterobacteriaceae-type strains and those available in the Genbank nucleotide sequence database (n = 24) were used as a database to identify 240 clinical enterobacteria isolates. Sequence analysis of the gyrBint fragment of 240 strains showed that gyrBint constitutes a discriminative target sequence to differentiate between Enterobacteriaceae species. Comparison of these identifications with those obtained by phenotypic methods (Vitek 1 system and/or Rapid ID 32E; bioMérieux, Marcy l'Etoile, France) revealed discrepancies essentially with genera Citrobacter and Enterobacter. Most of the strains identified as Enterobacter cloacae by phenotypic methods were identified as Enterobacter hormaechei strains by gyrBint sequencing. The direct sequencing of gyrBint would be useful as a complementary tool in the identification of clinical Enterobacteriaceae isolates.

Bacterial Typing Techniques↗

PubMed2005

Assessment of a new technique combining a viability test, whole-cell hybridization and laser-scanning cytometry for the direct counting of viable Enterobacteriaceae cells in drinking water.

A new direct approach, called direct viable count (DVC)-FISH-ScanRDI, combining viability measurement, specific detection and sensitive enumeration of highly diluted Enterobacteriaceae cells, was assessed during the summer in water samples from a North American drinking water treatment plant and its distribution system. Major results of this field investigation show a higher sensitivity of the DVC-FISH-ScanRDI approach in enumerating viable Enterobacteriaceae cells in distributed drinking water, relative to a culture-based method, and the increased concentration of viable but non-culturable (VBNC) Enterobacteriaceae cells in distributed water for temperatures above 18 degrees C.

Bacteriological Techniques↗

PubMed1988

Are antimitochondrial antibodies in primary biliary cirrhosis induced by R(rough)-mutants of enterobacteriaceae?

Antimitochondrial antibody (AMA)-positive serum samples from 45 patients with primary biliary cirrhosis (PBC) and AMA-negative serum samples from patients with chronic liver diseases, systemic lupus erythematosus, or rheumatoid arthritis were studied by an immunoblot technique with mitochondria from bovine heart and pig kidney and with several strains of gram-negative bacteria as antigens after separation by sodiumdodecylsulphate polyacrylamide gel electrophoresis. Serum from patients with PBC recognised up to three mitochondrial antigens with molecular weights of 70 kD, 50 kD, and 42 kD. Equivalent patterns were found with bands at 70-80 kD and 50-52 kD with Enterobacteriaceae as antigens. AMA-reactive polypeptides were localised in the ribosomal and membrane fractions from Enterobacteriaceae but differed from known outer membrane proteins. Conversely, PBC-specific mitochondrial antigens at 70 kD and 50 kD were recognised by rabbit antisera against Salmonella minnesota Rb and Rc mutants but not by antisera against wild-type Enterobacteriaceae. Absorption experiments and two-dimensional immunoblotting studies confirmed that mitochondria and gram-negative bacteria share identical PBC-specific determinants. It seems that PBC-specific antigens are expressed in gram-negative bacteria and that these antigens may be immunogenic in mutants with defective polysaccharide synthesis. The data support the hypothesis of a bacterial aetiology for PBC.

Adult↗

PubMed1997

Minimum growth temperatures of Hafnia alvei and other Enterobacteriaceae isolated from refrigerated meat determined with a temperature gradient incubator.

Minimum growth temperatures of Hafnia alvei (n = 156) and other Enterobacteriaceae isolates (n = 162) from refrigerated meat samples (n = 88) and control strains of H. alvei (n = 81) from clinical and environmental samples were determined with a plate-type continuous temperature gradient incubator on nutrient agar. The dominant species, Hafnia alvei and Serratia liquefaciens had mean minimum growth temperatures of 2.6 (range, 0.2-3.7 degrees C) and 1.7 (range, 0.2-2.6 degrees C), respectively. Values for other species included: Enterobacter agglomerans, 1.3 (0.7-1.7 degrees C); Escherichia coli, 8.7 (8.4-8.9); Escherichia vulneris, 1.6 (0.8-2.6 degrees C); and Serratia fonticola, 2.0 (1.1-3.0 degrees C). The H. alvei reference strains did not differ markedly from the meat isolates, with the exception of the diarrhoeagenic eae A positive strains (10.6, 10.2-11.5 degrees C). The representatives of H. alvei hybridization groups (HG) 1 and 2 did not differ in their minimum growth temperatures. The observed heterogeneity of the minimum growth temperatures of many Enterobacteriaceae species may be explained by limitations of the systems used for identification of enterobacteria, inadequacy of the Enterobacteriaceae taxonomy or true growth temperature heterogeneity within the various species.

Animals↗

PubMed2003

Simple and reliable multiplex PCR assay for detection of blaTEM, bla(SHV) and blaOXA-1 genes in Enterobacteriaceae.

Third-generation cephalosporin resistance is often mediated by TEM- and SHV-type beta-lactamases in Enterobacteriaceae. TEM-type and OXA-1 enzymes are the major plasmid-borne beta-lactamases implicated in amoxicillin-clavulanic acid resistance in Escherichia coli isolates. We have developed a rapid and simple multiplex polymerase chain reaction (PCR) which discriminates bla(TEM), bla(SHV) and bla(OXA-1) genes by generating fragments of 516, 392 and 619 bp respectively. Multiplex PCR analysis of 51 amoxicillin-clavulanate resistant E. coli isolates detected bla(TEM) and bla(SHV) genes in 45 and two strains, respectively, and only one strain harboured a bla(OXA-1) gene. Twenty-three of the 40 cefotaxime-resistant Enterobacteriaceae isolates produced amplicons with a size compatible with the presence of bla(TEM) (13 strains), bla(SHV) (six strains) genes or the association of both genes (four strains). These results were verified by colony hybridisation. Therefore, multiplex PCR is a suitable tool for initial rapid screening of bla genes in Enterobacteriaceae.

Amoxicillin↗

PubMedDate not supplied

Separation of Escherichia adecarboxylata from the "Erwinia herbicola-Enterobacter agglomerans" complex and from the other Enterobacteriaceae by nucleic acid and protein electrophoretic techniques.

The species Escherichia adecarboxylata was examined for DNA relatedness to the "Erwinia herbicola-Enterobacter agglomerans" complex and to other members of the family Enterobacteriaceae. DNA-DNA hybridizations (nitrocellulose filter method) showed that strains received as E. adecarboxylata were highly related to each other (73-100% homology). Three strains of E. agglomerans and one strain of E. herbicola showed, respectively, 77, 96, 97 and 92% relatedness with the labelled DNA of E. adecarboxylata. Two groups (E2 and E3) of "atypical coliforms" previously described by Gavini et al. (1983) showed high reassociation values (76-79% and 80-89%, respectively) with E. adecarboxylata. Most of these strains produced similar or nearly identical protein electrophoregrams. All these strains were therefore classified in E. adecarboxylata. This taxon yielded hybridization values lower than 53% with the previously described phenetic or genetic groups belonging to or related to the "herbicola-agglomerans" complex and values lower than 64% with 56 other species of the Enterobacteriaceae. It was concluded that E. adecarboxylata is a species different from E. agglomerans and the other species of the family Enterobacteriaceae. A new definition of the species E. adecarboxylata is presented.

Bacterial Proteins↗

PubMed1977

The reliability of the examination of foods, processed for safety, for enteric pathogens and Enterobacteriaceae: a mathematical and ecological study.

Because of the paucity of quantitative data on numbers of other enteric pathogens in food, the reliability of the examination of processed foods for Enterobacteriaceae was estimated taking Salmonella as a model. For this purpose an assessment was carried out of the risk of accepting Salmonella contaminated consignments of foods, despite a negative outcome of (i) examination of 1.5 kg samples for Salmonella; (ii) examination of one or two 1 g samples for Enterobacteriaceae; (iii) simultaneous application of both tests. The computations were based on the results of the examination of 6830 samples of dried foods, processed for safety, out of a total of 18170 samples.Only 69 samples permitted the exact calculation of the epsilon-factor, defined as c.f.u./g of Enterobacteriaceae/c.f.u./g of Salmonella; 4642 were positive for the former group but ;free' from Salmonella, and the rest were negative in both tests. Numbers of c.f.u./g for both groups, and hence the epsilon-factors, varied widely between commodities and also between different consignments of the same food product. The average for epsilon amounted to 5.8 x 10(3), far from the base-line value of 0.75 x 10(3) assessed earlier. In only 0.1% of samples did the Enterobacteriaceae test fail to achieve the required consumer protection.This investigation therefore substantiates that testing foods processed for safety by examining accurately chosen quantities for ecologically well selected and taxonomically thoroughly defined index organisms is a most effective procedure in terms both of consumer protection and simplicity of examination without compelling the food industry to achieve hardly attainable microbiological quality standards.

Bacteriological Techniques↗

PubMed1981

Comparison of the Microbact-12E and 24E systems and the API-20E system for the identification of Enterobacteriaceae.

The Microbact-24E and the Microbact-12E systems are two new miniaturized identification systems for the identification of organisms belonging to the family Enterobacteriaceae. These two systems were compared to the API-20E system for the identification of 352 fresh clinical isolates of Enterobacteriaceae. All three systems were easy to use and came complete with computerized profile registers to assist with final identification of the isolates. The Microbact-24E identified 98%, the API-20E and MB-12E identifying 94.3% and 88.6% respectively. Where different identifications were obtained with the Microbact-24E and API-20E conventional biochemical tests, motility and serology were performed. The Microbact-24E system proved to be a very accurate and convenient means of identifying members of the family Enterobacteriaceae.

Bacteriological Techniques↗

PubMed1988

Enterobacteriaceae suppression by three different oral doses of polymyxin E in human volunteers.

Polymyxin E is frequently used as an oral drug for flora suppression of the gastrointestinal canal. The suppression effect is dose dependent because polymyxin E is moderately inactivated by faecal and food compounds. Three oral polymyxin E doses (150, 300, 600 mg daily) were given to six volunteers for 6 days. The Enterobacteriaceae suppression effect was compared by means of the suppression index i.e. ratio of total number of faecal samples free of Enterobacteriaceae to the total number of faecal samples. The impact on the indigenous (mostly anaerobic) flora was measured in four ways: (i) beta-aspartylglycine content; (ii) volatile fatty acid pattern; (iii) yeast overgrowth and (iv) Streptococcus faecalis decrease. Enterobacteriaceae suppression was most successful during 600 mg oral polymyxin E (suppression indices during 150, 300 and 600 mg were 0.32, 0.55 and 0.89 respectively). None of the four markers of indigenous flora alterations were positive. However, using this dosage half of the volunteers suffered rather severe gastrointestinal side-effects. Oral polymyxin E in a dosage of minimum 600 mg daily seems to possess the ideal properties of a flora suppression agent, if the gastrointestinal side-effects could be mitigated.

Administration, Oral↗

PubMed2000

The capacity of Enterobacteriaceae species to produce biogenic amines in cheese.

The amino acid decarboxylating activity and production of biogenic amines by 104 cheese-associated Enterobacteriaceae species (58 Enterobacter, 18 Serratia, eight Escherichia, seven Hafnia, six Arizona, four Citrobacter and three Klebsiella) were investigated. All strains could decarboxylate at least two amino acids in Möller's broth and in Niven's medium, and the decarboxylase activity was strain specific. In a laboratory medium containing all free amino acids, all strains could produce more than 100 ppm cadaverine, putrescine was produced by 96% of strains. Tyramine and histamine were produced in the lowest concentrations. A positive correlation existed between cadaverine concentration and Enterobacteriaceae counts in cheese, that may have caused the increase in decarboxylase content. This study suggests that it is possible to limit the presence of cadaverine in cheese, thereby controlling the Enterobacteriaceae counts, a sign of contamination during cheese making and/or storage.

Biogenic Amines↗

PubMed2005

Clinical features of nosocomial infections by extended-spectrum beta-lactamase-producing Enterobacteriaceae in neonatal intensive care units.

AIM: To determine the risk factors for the acquisition of nosocomial extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae infection in infants hospitalized in neonatal intensive care units (NICUs) and to evaluate the therapeutic outcome of these infants. METHODS: We retrospectively reviewed the medical records of infants with nosocomial ESBL-producing Enterobacteriaceae infection hospitalized in NICUs at Chang Gung Children's Hospital in 2001. The clinical features of these infants were compared with a cohort of non-ESBL-producing Enterobacteriaceae-infected infants during the same period. The therapeutic outcome of the infants in the ESBL group was analysed. RESULTS: Seventy infants were included in this study. Thirty-one infants with 34 isolates were identified in the ESBL group and 39 infants with 42 isolates in the non-ESBL group. Of the parameters analysed, including gestational age, birthweight, length of hospital stay before onset, the number of antibiotics used, the duration of third-generation cephalosporin usage and the number of patients receiving a third-generation cephalosporin prior to the onset of infection, no significant difference was found between the two groups. The infection-contributed case fatality rate was 3.0% (1 of 33) in the ESBL group, not significantly different from that in the non-ESBL group (1 of 41, 2.4%). Of the 31 patients in the ESBL group, 18 were treated with a carbapenem as definitive therapy while 13 were treated with a non-carbapenem antibiotic regimen. No significant difference was noted in terms of mortality rate between the two subgroups. CONCLUSION: The outcome of the infants hospitalized in the NICU with ESBL-producing enterobacterial infections was not indispensably grave, even when treated with a non-carbapenem antibiotic regimen. The risk factors for the acquisition of ESBL-producing enterobacterial infections in these infants were not identified in this series.

Anti-Bacterial Agents↗

PubMed1989

In vitro activity of lomefloxacin (SC-47111) against enterobacteriaceae, enterococci and staphylococci.

The activity of lomefloxacin, a new difluorinated quinolone, was tested against 190 Enterobacteriaceae strains (belonging to 23 different species), 70 enterococci and 70 staphylococci. As regards Enterobacteriaceae, the activity of lomefloxacin was the same as that of norfloxacin in 9 out of the 23 species tested, and only slightly lower in further 8 species. Minimum inhibitory concentrations (MIC) values for 90% of strains were 0.5 microgram/ml in 2 species, 0.25 microgram/ml in 6, 0.125 microgram/ml in 4, and lower than 0.125 microgram/ml in 8. Slightly higher values were obtained for Serratia marcescens (2 micrograms/ml), whilst, as already reported for the other new quinolones, the susceptibility of the Providencia genus was very poor, with MIC values up to 128 micrograms/ml for the vast majority of strains. Lomefloxacin proved bactericidal at the MIC in all the Enterobacteriaceae strains tested but 20. In the latter strains, however, bactericidal activity could be appreciated at values slightly exceeding MIC. As regards enterococci, the MIC for 90% of strains was 32 micrograms/ml. Minimum bactericidal concentration (MBC) was the same as the MIC for 78% of the strains tested and was only twofold higher in all the others. The new drug was also active against staphylococci having an MIC50 and MIC90 of 0.5 and 2 micrograms/ml, respectively. It was bactericidal at the MIC for 62% of the strains and at twofold the MIC for all the others.

4-Quinolones↗

PubMed2000

High-pathogenicity island of Yersinia pestis in enterobacteriaceae isolated from blood cultures and urine samples: prevalence and functional expression.

Production of the siderophore yersiniabactin is associated with virulence in Yersinia species. The genes for biosynthesis and uptake of yersiniabactin are located on a high-pathogenicity island (HPI). The distribution and functioning of the Yersinia HPI were assessed in different Enterobacteriaceae strains isolated from blood cultures and urine samples. In total, 550 clinical isolates from 10 Enterobacteriaceae species were investigated by polymerase chain reaction and DNA hybridization. The Yersinia HPI was most prevalent in Escherichia coli (overall prevalence, 72.3%) and, to a lesser extent, in Klebsiella oxytoca (58.3%), Citrobacter species (25%), Klebsiella pneumonia (17.7%), and Enterobacter species (12.2%). The production of the siderophore yersiniabactin was also demonstrated in these HPI-positive strains by use of a reporter gene bioassay. These findings indicate that the HPI of Yersinia is distributed and functions in clinical specimens of different Enterobacteriaceae species.

Blood↗

PubMed2003

Resistance in Enterobacteriaceae: results of a multicenter surveillance study, 1995-2000.

OBJECTIVES: To assess changes over time in susceptibility of Enterobacteriaceae from patients in ICUs, compare susceptibility rates of isolates from patients in ICUs with those from inpatients outside ICUs, and explore phenotypic patterns of cross-resistance and co-resistance. DESIGN: From 1995 to 2000, centers participating in the ICU Surveillance Study tested 100 to 200 consecutive nosocomial gram-negative bacilli by broth microdilution. SETTING: Each year, 42 to 97 U.S. hospitals tested isolates. RESULTS: In all years, imipenem was the most potent agent tested, followed by amikacin and ertapenem. Extended-spectrum beta-lactam and monobactam agents had good activity against Escherichia coli and Klebsiella species, but limited activity against Enterobacter species. Susceptibility to imipenem and amikacin did not fluctuate during the analysis period, whereas susceptibility to ceftazidime, ceftriaxone, and ciprofloxacin decreased 2% to 5%. The decline was most pronounced for susceptibility of Escherichia coli to ciprofloxacin: 98.7% of ICU isolates were susceptible in 1995 versus 93.2% in 2000. Susceptibility of ICU isolates was lower than that of non-ICU isolates, except for ciprofloxacin, for which the reverse was true. Cross-resistance was common among extended-spectrum cephalosporins and penicillins, but uncommon between imipenem and ertapenem. Only imipenem and ertapenem remained highly active against Enterobacteriaceae with a phenotype suggesting possible production of an extended-spectrum beta-lactamase and those with a phenotype suggesting possible Amp C hyperproduction. CONCLUSIONS: Imipenem was the most active agent against nosocomial Enterobacteriaceae. Susceptibility to ciprofloxacin decreased from 1995 to 2000, particularly in Escherichia coli, and, in contrast to other agents, was lower among non-ICU isolates.

Cross Infection↗