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PubMed2000

Enterococcus hirae enteropathy with ascending cholangitis and pancreatitis in a kitten.

A 2-month-old female Persian cat that had been showing episodes of anorexia and diarrhea for the previous 4 weeks was presented in shock and died 2 days later. Numerous Gram-positive cocci were located along the brush border of small intestinal villi, without significant inflammatory infiltration. Similar bacteria were present within hepatic bile ducts and pancreatic ducts and were associated with suppurative inflammation and exfoliation of epithelial cells. Culture of the liver and lung yielded bacteria identified as Enterococcus hirae. Fecal culture from an asymptomatic adult female from the same cattery also yielded large numbers of E. hirae. To our knowledge, this is the first report of E. hirae enteropathy in a cat and the first report of ascending cholangitis and ductal pancreatitis caused by an Enterococcus spp.

Animals↗
PubMed1998

European Glycopeptide Susceptibility Survey of gram-positive bacteria for 1995. European Glycopeptide Resistance Survey Study Group.

In the European Glycopeptide Susceptibility Survey 7078 Gram-positive isolates collected in 1995 from 70 centers in 9 countries of Western Europe were examined, using a standardized, quantitative susceptibility testing method. Of the 7078 isolates, 6824 (96.4%) were tested by the national coordinating centers. Teicoplanin (mode MIC 0.5 microgram/mL) was generally twice as active as vancomycin (mode MIC 1 microgram/mL) against Staphylococcus aureus (n = 2852). All isolates were susceptible to vancomycin (MIC < or = 4 micrograms/mL) and all but four to teicoplanin (MIC < or = 8 micrograms/mL); these four isolates were of intermediate susceptibility (MIC 16 micrograms/mL). With coagulase-negative staphylococci (n = 1444), the distribution of MIC of teicoplanin was wider than for vancomycin. Two and two-tenths percent of coagulase-negative staphylococci excluding Staphylococcus haemolyticus required 16 micrograms/mL teicoplanin for inhibition (intermediate) and 0.4% > or = 32 micrograms/mL (resistant). Among isolates of S. haemolyticus, 4.4% were of intermediate susceptibility (MIC 16 micrograms/mL) and 3.3% were resistant (MIC > or = 32 micrograms/mL) to teicoplanin. However, this species represented only 6.3% of the isolates of coagulase-negative Staphylococcus spp. Generally, teicoplanin (mode MIC < or = 0.12 microgram/mL) was four to eight times more active than vancomycin (mode MIC < or = 0.5 microgram/mL) against the 770 streptococcal isolates. Glycopeptide-susceptible Enterococcus spp. (n = 1695) were generally four times more susceptible to teicoplanin (mode MIC 0.25 microgram/mL) than to vancomycin (mode MIC 1 microgram/mL). Combined vancomycin and teicoplanin (VanA phenotype) resistance was observed more frequently (9.3%) in isolates of Enterococcus faecium than in Enterococcus faecalis (0.8%). Four isolates of unspeciated enterococci (1.4%) also expressed this resistance phenotype. Four isolates of E. faecium and four of E. faecalis expressed the VanB-type (low-level, vancomycin only) resistance. Spain was the only country not to submit resistant E. faecium strains while resistant E. faecalis isolates came only from Spain and Italy.

Anti-Bacterial Agents↗
PubMedDate not supplied

Antimicrobial activity of Ro 24-6778, a covalent bonding of desmethylfleroxacin and desacetylcefotaxime.

A new "dual action" cephalosporin (Ro 24-6778), representing an ester-linked desacetylcefotaxime and desmethylfleroxacin was tested against 287 aerobic bacteria. Ro 24-6778 was found to be very active (minimal inhibitory concentrations [MIC90], less than or equal to 0.5 micrograms/ml) against Enterobacteriaceae, Streptococcus spp., and Aeromonas hydrophila. Moderate Ro 24-6778 activity (MIC90, 1-8 micrograms/ml) was demonstrated against Bacillus spp., Staphylococcus spp. (including oxacillin-resistant strains), Flavobacterium spp., Enterococcus durans, and Acinetobacter anitratus. More Ro 24-6778-resistant strains (MIC90, 16- greater than 32 micrograms/ml) were usually found among the enterococci, Xanthomonas hydrophila, Pseudomonas spp., and Achromobacter xyloxidans isolates. These preliminary Ro 24-6778 MIC test results show a spectrum superior (93.4% of strains susceptible at less than or equal to 8 micrograms/ml) to the comparison drugs (cefotaxime or fleroxacin) and possible clinical utility for therapy of many fluoroquinolone- or cephalosporin-resistant strains.

Anti-Bacterial Agents↗
PubMed1989

Antimicrobial activity of Ro 23-9424, a novel ester-linked codrug of fleroxacin and desacetylcefotaxime.

Ro 23-9424 is a novel ester-linked codrug of fleroxacin (Ro 23-6240; AM-833) and the cefotaxime metabolite desacetylcefotaxime. Its potency was determined against over 1,000 organisms and found to be intermediate between those of the two components. More than 99% of members of the family Enterobacteriaceae were inhibited by greater than or equal micrograms of Ro 23-9424 per ml; its MIC for 50% of strains tested ranged from greater than or equal to 0.06 to 1 micrograms/ml. Staphylococci, streptococci, Branhamella catarrhalis, Corynebacterium jeikeium, Bacillus spp., Haemophilus influenzae, Listeria monocytogenes, and the pathogenic Neisseria spp., including oxacillin-resistant Staphylococcus aureus, beta-lactamase-producing strains, and penicillin-resistant pneumococci, were also inhibited by Ro 23-9424. Pseudomonas aeruginosa, Enterococcus spp., and Bacteroides fragilis group isolates were more refractory to Ro 23-9424 (the MIC for 90% of strains tested was less than or equal to 32 micrograms/ml). Overall, Ro 23-9424 inhibited 97% of the aerobic strains, compared with 90% for ceftazidime and 92% for cefoperazone. Ro 23-9424 was bactericidal, was relatively stable to inoculum effects on MICs at 10(7) CFU/ml, and was determined to be highly active against organisms resistant to fluoroquinolones or ceftazidime. Preliminary quality control guidelines were determined, and a 30-micrograms disk concentration appears to be the most usable form.

Anti-Infective Agents↗
PubMed1997

[Trends and changes in antimicrobial resistance of clinical isolates from 11 hospitals in Beijing area].

OBJECTIVE: To study the antimicrobial resistance and its changes of clinical isolates in Beijing area. METHODS: The diameters of the inhibition zones of clinical isolates around antibiotic susceptibility test discs at 12 hospitals in Beijing area were computerfiled and analysed by the software of 'WHONET' according to NCCLS published in 1994. RESULTS: A total of 10,305 isolates were collected in 1995. The percentages of resistance were as follows: (1) in E. coli: amikacin, 8%, ceftazidime, 15%, the other third generation cephalosporins, about 30%, (2) in Klebsiella spp: ofloxacin, 0%, ceftazidime, 15%, ciprofloxacin, 17%, norfloxacin, 15%, ofloxacin, 5%, (4) in Staph. aureus: norvancomycin, 0%, (5) in Strep. pneumoniae: penicillin G, 9%, (6) in Enterococcus spp: norvancomycin, 7%. The antimicrobial resistant changes over a six year period from 1990 to 1995 were surveyed and it was found that resistant percentage of the most isolates to quinolones, for example norfloxacin, increased significantly year by year and no remarkable differences of resistance to antimicrobial agents but quinolones were observed in Ps. aeruginosa. CONCLUSION: Antimicrobial resistance should be emphasised during clinical therapy with antimicrobial agents, and trends in antimicrobial resistance of isolates should be followed.

Anti-Infective Agents↗
PubMed1997

Strategy for detection and identification of bacteria based on 16S rRNA genes in suspected cases of Whipple's disease.

The 16S ribosomal RNA (rRNA) gene of the phylogenetic subdivision containing gram-positive bacteria with a high G + C content was detected specifically in clinical specimens from patients suspected of having Whipple's disease. The primary structure of 16S rDNA amplified from clinical samples was determined by cloning and sequencing. Two sorts of sequences were identified: one corresponded exactly to the rRNA sequence of Tropheryma whippelii (GenBank accession no. M87484) while the other was related to that of members of the genus Corynebacterium. No sequence related to Mycobacterium spp. or Rhodococcus equi was observed. Exhaustive examination of negative specimens with broad-range eubacterial primers detected one sequence related to Enterobacteriaceae and another related to Enterococcus spp. To speed identification of T. whippelii, a nested amplification method was devised. A first amplification specific for the gram-positive bacteria subdivision was performed, followed by a second amplification with T. whippelii-specific primers. The amplified T. whippelii product was checked by digestion with AvaII, StuI, and PstI endonucleases. These techniques were applied to DNA extracted from seven intestinal biopsy samples, two cerebrospinal fluid samples and one articular fluid from patients suspected of having Whipple's disease. T. whippelii 16S rDNA was found in two of the biopsy samples, one of the cerebrospinal fluid samples and in the articular fluid.

Actinobacteria↗
PubMed1992

The comparative activity of fleroxacin, three other quinolones and eight unrelated antimicrobial agents.

The in vitro activity of fleroxacin, a new trifluorinated quinolone was evaluated against 432 bacterial isolates. Fleroxacin was 1- to 2-fold less active than ciprofloxacin and at least as active as ofloxacin and lomefloxacin against most members of the family Enterobacteriaceae. The MICs of fleroxacin for 90% of strains tested (MIC90) were < or = 0.25 micrograms/ml against all isolates of Enterobacteriaceae except Citrobacter freundii (MIC90, 4 micrograms/ml) and Serratia marcescens (MIC90, 2 micrograms/ml). Fleroxacin was as active as ciprofloxacin, ofloxacin and lomefloxacin against Pseudomonas spp, (MIC90 for all quinolones tested were > 8 micrograms/ml). Acinetobacter and Haemophilus influenzae were very susceptible to fleroxacin; however fleroxacin was 1-fold less active than lomefloxacin against Acinetobacter and at least 1-fold less active than ciprofloxacin or ofloxacin against H. influenzae. Methicillin-susceptible and -resistant strains of Staphylococcus epidermidis and methicillin-susceptible strains of S. aureus were very susceptible to fleroxacin, with an MIC90 < or = 1 microgram/ml (range 0.5-1 microgram/ml). Methicillin-resistant S. aureus and Staphylococcus spp. other than aureus and epidermidis were not susceptible to fleroxacin (MIC90 > 8 micrograms/ml). In addition, fleroxacin as well as ciprofloxacin, ofloxacin and lomefloxacin were inactive against Enterococcus spp. (MIC90 > 8 micrograms/ml). Streptococcus pneumoniae and S. pyogenes were resistant to both fleroxacin and lomefloxacin but were very susceptible to ciprofloxacin and ofloxacin. These results suggest that fleroxacin represents a valid therapeutic option in the treatment of infections caused by most Enterobacteriaceae and some species of staphylococcus.

Anti-Bacterial Agents↗
PubMed2005

Microbiological profile of neonatal septicemia in a pediatric care hospital in Delhi.

Septicemia continues to be an important cause of morbidity and mortality in the neonatal units and periodic review of cases to assess any changing trends in the infecting organisms and their antimicrobial susceptibility is important. Over a period of one year (July 2000 to June 2001), 632 samples of blood cultures were submitted to the bacteriology laboratory Microbiology, Lady Hardinge Medical College. These samples were investigated for microbial etiology and the isolates obtained were tested for their susceptibility to the commonly used antibiotics. Twenty per cent (125) cases were culture positive. Gram-negative bacteria were the predominant isolates (62%), commonest being Klebsiella pneumoniae (34%) followed by E. coli (17%), Acinetobacter spp. (9%) and Enterobacter aerogenes (2%). Gram-positive cocci were isolated in 20% cases, of which coagulase negative staphylococcus was the predominant isolate (11%) followed by Enterococcus spp. (5%) and S. aureus (4%). Candida spp. was isolated from 18% of cases. Resistance to commonly used antibiotics was seen in more than 35% of isolates. An alarming observation was the very high incidence of resistance to amoxycillin+clavulanic acid and ceftriaxone (>80%). All isolates showed highest susceptibility to ciprofloxacin.

Anti-Bacterial Agents↗
PubMed1999

Fusidic acid in vitro activity.

Fusidic acid is a narrow spectrum agent that acts to inhibit protein synthesis by inhibition of elongation factor G at the level of the ribosome. Because of high protein binding susceptibility testing in vitro is affected by the presence of blood or serum. In addition, there is a modest inoculum effect in vitro. A breakpoint of 1 or 2 mg/l is most widely used for defining resistance to systemic treatment with fusidic acid. Fusidic acid activity is principally directed at staphylococci, both Staphylococcus aureus and coagulate-negative species which are highly susceptible. It is also active against Gram-positive anaerobic activity, and shows in vitro activity against Neisseria spp., Bordetella pertussis and Moraxella catarrhalis. It has no activity against other aerobic Gram-negative species. Modest activity (MICs just above breakpoint values) is seen with Streptococcus and Enterococcus spp. as well as Gram-negative anaerobic bacteria. Fusidic acid is defined as bacteriostatic. For staphylococci MBC values are generally 8--32-fold that of the MIC. Interaction studies with other antibiotics give varying results depending on methodology. However, interaction with beta-lactams is generally indifferent, as it is with rifampicin, while aminoglycosides and macrolides appear to be synergistic and fluoroquinolones antagonistic. Fusidic acid appears to inhibit the function of neutrophils and T-lymphocytes at clinically achieved concentrations.

Anti-Bacterial Agents↗
PubMed1999

Surveillance of antibiotic resistance in Taiwan, 1998.

For the first national surveillance of antibiotic resistance in Taiwan, we collected in 1998 from 22 hospitals (6 medical centers, 15 regional hospitals, and 1 local hospital) 3,211 isolates in all parts of the country. Besides 50 random successive isolates from inpatients, each hospital was requested to collect 25 isolates each from positive blood cultures, hospital-acquired infections, outpatients and the pediatric department. We re-speciated all the submitted specimens and determined their antibiotic susceptibility patterns. The most common isolates were Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae), Staphylococcus aureus, and Pseudomonas aeruginosa. Among hospital-acquired infections, Acinetobacter spp. were among those which accounted for over 10% of the isolates. The oxacillin resistance of S. aureus was 82% in isolates from hospital-acquired infections, and 40% from outpatients. Among Enterococcus spp., 85% were either E. faecalis or E. faecium. They were 14% resistant to vancomycin. Among gram-negative bacteria, K. pneumoniae and Acinetobacter baumanii were hospital-acquired isolates that were most clearly more resistant than community acquired isolates. This difference was less apparent in the case of Enterobacter cloacae, Serratia marcescens, and P. aeruginosa. These bacteria were generally more resistant from all sources. Fifty-one percent of Salmonella were resistant to ampicillin; however, these were all sensitive to ciprofloxacin. Isolates from the East were least resistant. Plotting the disc zone diameters of antibiotics within the susceptible range, we identified subpopulations with smaller diameters in the case of vancomycin against S. aureus, ciprofloxacin against E. coli, and ciprofloxacin against Salmonella spp. These findings represent one of the purposes of this surveillance as they may portend developing resistances which bear careful watching in the future.

Ciprofloxacin↗
PubMed2001

Molecular screening of Enterococcus virulence determinants and potential for genetic exchange between food and medical isolates.

Enterococci are used as starter and probiotic cultures in foods, and they occur as natural food contaminants. The genus Enterococcus is of increased significance as a cause of nosocomial infections, and this trend is exacerbated by the development of antibiotic resistance. In this study, we investigated the incidence of known virulence determinants in starter, food, and medical strains of Enterococcus faecalis, E. faecium, and E. durans. PCR and gene probe strategies were used to screen enterococcal isolates from both food and medical sources. Different and distinct patterns of incidence of virulence determinants were found for the E. faecalis and E. faecium strains. Medical E. faecalis strains had more virulence determinants than did food strains, which, in turn, had more than did starter strains. All of the E. faecalis strains tested possessed multiple determinants (between 6 and 11). E. faecium strains were generally free of virulence determinants, with notable exceptions. Significantly, esp and gelE determinants were identified in E. faecium medical strains. These virulence determinants have not previously been identified in E. faecium strains and may result from regional differences or the evolution of pathogenic E. faecium. Phenotypic testing revealed the existence of apparently silent gelE and cyl genes. In E. faecalis, the trend in these silent genes mirrors that of the expressed determinants. The potential for starter strains to acquire virulence determinants by natural conjugation mechanisms was investigated. Transconjugation in which starter strains acquired additional virulence determinants from medical strains was demonstrated. In addition, multiple pheromone-encoding genes were identified in both food and starter strains, indicating their potential to acquire other sex pheromone plasmids. These results suggest that the use of Enterococcus spp. in foods requires careful safety evaluation.

Animals↗
PubMed1992

Susceptibility testing of clinical isolates of Enterococcus faecium and Enterococcus faecalis.

We collected 103 clinical Enterococcus faecium isolates from across Canada, performed standard broth microdilution susceptibility testing, and compared these results with results from the MicroScan Pos MIC Type 6 panel (Baxter Health Care Corp., West Sacramento, Calif.) and the AMS-Vitek Gram-Positive Susceptibility card (Vitek Inc., St. Louis, Mo.). High-level aminoglycoside resistance to gentamicin and streptomycin was detected by a single-concentration agar method with 1,000 micrograms of each aminoglycoside per ml. In addition, we tested the effect of the lower calcium content in broth media as recommended in National Committee for Clinical Laboratory Standards (NCCLS) guideline M7-A2 on the activity of the highly calcium-dependent agent daptomycin. Of the 103 E. faecium isolates, there were 4 and 30 isolates with high-level gentamicin resistance (HLGR) and high-level streptomycin resistance (HLSR), respectively. An additional 39 (37 with HLGR and 36 with HLSR) E. faecium isolates were tested by both the MicroScan and the AMS-Vitek systems. The AMS-Vitek card demonstrated sensitivities of 95 and 82% for detecting HLGR strains and HLSR strains, respectively. The MicroScan panel demonstrated improved sensitivities for detecting HLGR (42 to 97%) and HLSR (64 to 84%) when readings were performed manually instead of being generated automatically. Ampicillin resistance (MIC, greater than or equal to 16 micrograms/ml) was detected in 23 of the 103 E. faecium isolates. Only 14 and 20 of these were detected by the MicroScan panels and AMS-Vitek cards, respectively. beta-Lactamase activity was not detected in any isolates. The lower calcium content in broth media recommended by NCCLS guideline M7-A2 markedly reduced the in vitro activity of daptomycin against Enterococcus spp.

Calcium↗
PubMed1998

DNA sequence variation within vanA, vanB, vanC-1, and vanC-2/3 genes of clinical Enterococcus isolates.

We studied the DNA sequence variation of van genes of 34 isolates of Enterococcus spp. The isolates containing the vanB gene exhibited between 0 and 41 base pair changes per 801 bp studied when the vanB sequences were compared to that of the reference strain Enterococcus faecalis V583. The isolates carrying the vanC-2 gene exhibited between 0 and 23 base pair changes per 346 bp studied when the vanC-2 sequences were compared to that of the reference strain E. casseliflavus ATCC 25788. Little variation was noted in the vanA and vanC-1 genes.

Amino Acid Sequence↗
PubMed1997

Multidrug-resistant gram-positive pathogens. An update on current microbiological patterns.

Although resistance has developed among Gram-positive pathogens to penicillins, cephalosporins, aminoglycosides, quinolones and macrolides, the glycopeptides seem to remain largely unaffected. However, the recent emergence and range of glycopeptide resistance in enterococci, well documented in the USA but not in the rest of the world, have prompted this European surveillance study. The European Glycopeptide Resistance Survey was undertaken in 1995 in 9 countries and involved 70 microbiological centres. The primary aims of the survey were as follows: (i) to perform a microbiological quality assurance assessment to evaluate the ability of participating laboratories to correctly identify the strains and assess their glycopeptide susceptibility; and (ii) to accurately determine the level of glycopeptide resistance among staphylococci, streptococci and enterococci in European hospitals. The in vitro activity of several other antibiotics was assessed on strains isolated from the Italian centres. In total, 7078 Gram-positive isolates were collected in Europe, and national coordinators used the National Committee for Clinical Laboratory Standards (NCCLS) agar dilution reference method to successfully retest 96% of these. According to mode minimum inhibitory concentrations (MICs), teicoplanin activity was similar to that of vancomycin against Staphylococcus aureus. In general, the range of MICs for teicoplanin was wider than that for vancomycin against coagulase-negative staphylococci. Against Enterococcus spp. and Streptococcus spp., teicoplanin was 4 times more active than vancomycin. The greatest number of glycopeptide refractory organisms was evident among enterococci; resistance was observed to be approximately 10 times more frequent in Enterococcus faecium than in E. faecalis. The results from the Italian isolates were similar to those from the overall study. In particular, teicoplanin was 2- to 8-fold more active than vancomycin against the majority of the enterococci. The incidence of enterococcal resistance was lower in Italy (0.6% for teicoplanin and 0.9% for vancomycin) than in Europe (1.7% for teicoplanin and 2.3% for vancomycin). This extensive survey confirms that teicoplanin is more active than vancomycin against enterococci and streptococci, and that both display similar potency against staphylococci.

Anti-Bacterial Agents↗
PubMed1992

In vitro antimicrobial activity of cefodizime, a third generation cephalosporin.

Cefodizime is one of the new broad-spectrum cephalosporins. It is an aminothiazolyl iminomethoxy cephalosporin which is metabolically stable and has a prolonged serum half life. Cefodizime was primarily active against gram-negative bacilli and at the concentration of 0.5 mg/L, it inhibited 90 per cent of Enterobacteriaceae. P. mirabilis was the most susceptible species tested (MIC90 of 0.02 mg/L). E.coli, K.pneumoniae, Salmonella spp., Shigella spp. and M. morganii were also very sensitive to cefodizime, with the MIC90 of 0.25-0.5 mg/L. Cefodizime, however, was not active against most gram-negative bacilli possessing Type I beta-lactamases of Richmond and Sykes, namely, Enterobacter spp., P. aeruginosa and A. anitratus (MIC90 of > 128 mg/L). Among gram-positive bacteria, only S.pyogenes was highly susceptible (MIC90 of 0.05 mg/L), while S. aureus (methicillin-sensitive) was moderately susceptible and Enterococcus spp. was resistant. Cefodizime appeared to be bactericidal and was not affected by serum. High inoculum (10(7) cfu/ml) of K.pneumoniae and Enterobacter spp. resulted in increase of the MIC of cefodizime. This study shows that local bacterial isolates in a university hospital in Bangkok, Thailand were not different in susceptibility pattern from those reported in developed countries. The in vitro activity of cefodizime as a third generation cephalosporin, with its good pharmacokinetic property, and the property of the agent as a biological response modifier, should prove that this is a promising new agent in treating serious infections especially in immunosuppressed hosts.

Cefotaxime↗
PubMed2002

Isolation of Enterococcus species from infectious skin lesions.

Enterococcus faecalis was isolated at a frequency of 70% and was chiefly isolated from secondary infections due to ulcer/decubitus. Seven sole/predominant E. faecalis were isolated. Penicillins were more effective against E. faecalis and the sensitivities of E. faecalis to antimicrobials were higher than those of E. faecium. Some nonpredominant E. faecalis strains were sensitive to erythromycin probably due to less resistant mechanisms. The characterization of Enterococcus spp. is especially important when choosing appropriate antimicrobials for therapy.

Anti-Bacterial Agents↗
PubMed2002

Antibiotic resistance: effect of different criteria for classifying isolates as duplicates on apparent resistance frequencies.

OBJECTIVE: To investigate the effect of screening specimens and different criteria for exclusion of duplicate isolates when surveillance of antimicrobial resistances is performed. MATERIALS AND METHODS: Trends in resistance were analysed for recent isolates of selected organisms from Guy's and St Thomas' Hospitals with the use of various criteria for the exclusion of duplicates, including time since the last isolate and antibiogram pattern, and the effect of excluding screening specimens. RESULTS: There was a significant difference of about 8% in the apparent frequency of methicillin resistance in Staphylococcus aureus in inpatients if the time limit for duplicates was set at 5 rather than 30 days; it was about 10% if a 5 day limit was compared with a 365 day limit. There was also a significant difference, of 6-10%, in apparent resistance frequencies if isolates from screening specimens were excluded. Apparent gentamicin resistance rates in Klebsiella spp. varied between 11% and 28%, and the number of apparent patient isolates of gentamicinresistant organisms varied by up to 35%, depending on the duplicate exclusion criteria chosen. Effects were smaller, though still significant, for vancomycin resistance in Enterococcus spp. There was little effect for amoxicillin or cefuroxime resistance in Escherichia coli isolates from general practitioners, where the proportion of duplicates was small. CONCLUSION: Improved surveillance of antibiotic resistance is needed. However, care needs to be taken in setting the criteria for classifying isolates as duplicates and in comparing results where these criteria may be different or unknown.

Bacteria↗
PubMed2001

Identification of enterococcal isolates by temperature gradient gel electrophoresis and partial sequence analysis of PCR-amplified 16S rDNA variable V6 regions.

Based on partial sequence analysis of PCR-amplified 16S rDNA variable V6 regions of 14 enterococcal type strains, Enterococcus faecalis, Enterococcus mundtii, Enterococcus gallinarum, Enterococcus avium, Enterococcus raffinosus and Enterococcus saccharolyticus showed characteristic sequence motifs which made it possible to separate them into six individual species lines. Furthermore, two species cluster groups could be identified, including (i) Enterococcus faecium, Enterococcus durans, Enterococcus hirae, Enterococcus malodoratus, and (ii) Enterococcus casseliflavus/Enterococcus flavescens, Enterococcus pseudoavium, Enterococcus dispar and Enterococcus sulfureus. There were identical DNA sequences in the V6 region within each group. Temporal temperature gradient gel electrophoresis (TTGE) of the PCR products from 16 type strains, 12 enterococcal reference strains and 8 clinical isolates revealed that a single nucleotide divergence in DNA sequences was sufficient for separation, identification and division of the studied enterococcal strains into corresponding TTGE profiles. It was concluded that partial DNA sequence analysis and TTGE profiling of PCR-amplified 16S rDNA variable V6 regions provide useful tools for the identification of clinically important Enterococcus spp.

Bacterial Typing Techniques↗