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T M Coque

Publications and source records attributed to T M Coque.

At least 19 recordsLinked to original sources
PubMed2006

Genetic and phenotypic differences among Enterococcus faecalis clones from intestinal colonisation and invasive disease.

This study investigated the differences among Enterococcus faecalis isolates from the intestinal compartment of healthy volunteers (n = 36), intensive care unit (ICU) patients (n = 29) and blood isolates (n = 31) from the same institution, in comparison with seven epidemic clones from other institutions. In general, isolates from colonised ICU patients and from bacteraemic patients showed higher rates of antimicrobial resistance than isolates from colonised healthy volunteers, particularly for erythromycin and aminoglycosides. The proportion of isolates/clone was 1.05 in the community, 2.63 in the ICU, and 1.47 among bacteraemic cases, suggesting low clonal variation in ICUs. Two clones, RENC1 and RENC2, were frequently found as intestinal colonisers of ICU patients, and RENC1 was also found to colonise healthy volunteers. These two clones were a cause of bacteraemia in the institution studied, and RENC2 was also detected in various other Spanish hospitals. Both RENC1 and RENC2 were esp+, bacteriocin producers, and were resistant to all antibiotics tested except vancomycin and ampicillin. RENC1 produced haemolysin whereas RENC2 produced protease. The ace, agg, cylA, esp and gelE genes were more common among colonising strains from ICU patients than among isolates from individuals in the community. In both colonised groups (ICUs and the community), 40-50% of isolates harbouring the gelE and cylA genes did not express the corresponding phenotypes. Thus, the study indicated that particular E. faecalis clones might be well-adapted to hospital environments, and that surveillance should be directed specifically towards rapid detection of these disseminating clones in order to prevent infections and clonal spread.

Antigens, Bacterial↗
PubMed2006

Antimicrobial resistance among faecal enterococci from healthy individuals in Portugal.

Analysis of 247 faecal enterococcal isolates from 99 healthy Portuguese individuals during 2001 revealed the presence of enterococci resistant to vancomycin (5%) and highly resistant to streptomycin (52%), kanamycin (40%) or gentamicin (11%). Most isolates were also resistant to tetracycline, erythromycin, ciprofloxacin and quinupristin-dalfopristin. The vanA (two Tn1546 types), vanC1, erm(B), aac(6')-aph(2'')-Ia, aph(3')-IIIa, vat(E) and vat(D) genes were detected. Enterococcus faecalis and Enterococcus faecium isolates with high-level resistance to gentamicin were related to Portuguese poultry isolates described previously. E. faecium isolates that were highly resistant to vancomycin or gentamicin harboured different housekeeping purK alleles associated previously with different hosts.

Animals↗
PubMed2005

High occurrence and persistence of antibiotic-resistant enterococci in poultry food samples in Portugal.

OBJECTIVES: We determined the presence of antibiotic-resistant enterococci (ARE) in commercialized poultry samples from Portugal and analysed their clonal diversity and the resistance genes harboured by these strains. METHODS: Ninety-nine retail poultry samples of 10 widely commercialized brands were studied (1999-2001). Samples were enriched and plated on selective media with and without vancomycin, gentamicin, streptomycin or kanamycin. Antibiotic susceptibility was established following standard criteria. Identification and detection of genes coding for resistance were determined by PCR. Clonal relatedness was established by PFGE. RESULTS: A high percentage of samples contained vancomycin-resistant enterococci (VRE) (48%), or enterococci highly resistant (HLR) to gentamicin (34%), streptomycin (32%) or kanamycin (30%). Co-resistance to tetracycline, erythromycin, ciprofloxacin and quinupristin/dalfopristin was observed in most of these isolates. VRE were classified as VanA phenotype-vanA genotype (38% of samples), VanB phenotype-vanA (13%) or VanC phenotype-vanC1 (23%). All HLR to gentamicin isolates contained aac(6')-Ie-aph(2'')-Ia. We detected erm(B) in both erythromycin-resistant and -susceptible isolates. Some VRE and HLR to gentamicin strains were recovered from different samples and brands. Long-term persistence of particular VRE strains (>2 years), exhibiting different Van phenotypes, was observed. CONCLUSIONS: High occurrence of ARE suggests maintenance of selective pressure by the use of antibiotics/other substances in the Portuguese poultry environment. Persistence of a number of widespread PFGE types containing different resistance genes might reflect environmental/host-adapted enterococcal strains that might contribute to the maintenance of antibiotic resistance, thus constituting a resistance reservoir that is non-sensitive to banning interventions.

Acetyltransferases↗
PubMed2005

Nationwide study of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum beta-lactamases in Spain.

Clonal dissemination of extended-spectrum beta-lactamases (ESBL) in 170 Escherichia coli isolates and 70 Klebsiella pneumoniae isolates from a nationwide study of 40 Spanish centers in 2000 was not observed in most centers. The most prevalent ESBL were CTX-M-9 (27.3%), SHV-12 (23.9%), and CTX-M-14 (20.5%) for E. coli and TEM-3 (16.7%) and TEM-4 (25%) for K. pneumoniae. A new ESBL, TEM-133, with mutations L21F, E104K, and R164S, was identified.

Anti-Infective Agents↗
PubMed2004

Emergence of CTX-M beta-lactamase-producing Enterobacteriaceae in Portugal: report of an Escherichia coli isolate harbouring blaCTX-M-14.

CTX-M beta-lactamases have been reported worldwide since their first description in the early 1990s, and are now endemic in some countries. This report describes an isolate of Escherichia coli producing CTX-M-14 that was recovered from the faecal sample of a healthy subject in Portugal without recent hospital or antibiotic exposure. The presence of ISEcp1, 42 nucleotides upstream of bla(CTX-M-14), and its association with a 100-kb conjugative plasmid, might result in wider dissemination of this enzyme in community and hospital environments in Portugal.

Aged↗
PubMed2003

Antimicrobial resistance in recent fecal enterococci from healthy volunteers and food handlers in Spain: genes and phenotypes.

Susceptibility patterns to 15 different antibiotics and the presence of resistance genes were evaluated in recent fecal Enterococcus isolates recovered from 42 healthy volunteers (HV) and 43 food-handlers (FH). A total of 142 Enterococcus faecalis, 74 Enterococcus faecium, and 23 Enterococcus spp. with different antibiotic susceptibility patterns were studied. A higher percentage of resistance for moxifloxacin, erythromycin, glycopeptides and high-level resistance (HLR) to gentamicin were observed in the FH group. Ampicillin- or linezolid-resistant isolates were not recovered in any of the groups. The tet(M) gene was found in 96% and in 85% of tetracycline-resistant isolates from HV and FH, respectively. HLR-kanamycin was mediated by aph(3')-IIIa, or aac(6')-aph(2"), or both genes in all isolates from HV group and in 86% from FH group. The aac(6')-aph(2") gene was found in all HLR-gentamicin isolates. Ninety-one percent of HV and 71% of FH erythromycin-resistant isolates harbored the erm(B) gene (erythromycin MIC range of 8-128 microg/ml), whereas erm(A), erm(C), or mef(A) genes were not detected. Coexistence of erm(B), aph(3')-IIIa, and tet(M) genes was observed in 17% of the isolates of both groups. The HLR-gentamicin isolates presented unrelated PFGE patterns while 2 out of 3 vanA E. faecium isolates showed an indistinguishable SmaI-pulsed-field gel electrophoresis (PFGE) pattern. This study shows that despite 4 years of official banning of antibiotic growth promoters in animals, enterococci isolated from FH are more resistant than those from HV. This suggests the permanence of resistant clones or transferable resistance elements in farms and a possible exchange between food products and humans, or eventually the long-term permanence of certain clones in the FH intestinal tract.

Anti-Bacterial Agents↗
PubMed2001

Nucleotide sequence and characterization of a novel cefotaxime-hydrolyzing beta-lactamase (CTX-M-10) isolated in Spain.

A cefotaxime-resistant, ceftazidime-susceptible Escherichia coli isolate was obtained from a patient with sepsis in 1997, from which a beta-lactamase with a pI of 8.1 was cloned. Cephaloridine and cefotaxime relative hydrolysis rates were 167 and 81, respectively (penicillin G rate = 100), whereas ceftazidime hydrolysis was not detected. The nucleotide sequence revealed a bla gene related to that coding for CTX-M-3. Despite 21 nucleotide substitutions, only 2 determined amino acid changes (Ala27Val and Arg38Gln). The amino acid sequence identity between this enzyme, designated CTX-M-10, and the chromosomal beta-lactamase of Kluyvera ascorbata was 81%.

Cefotaxime↗
PubMed1999

Characterization of dihydrofolate reductase genes from trimethoprim-susceptible and trimethoprim-resistant strains of Enterococcus faecalis.

Enterococci are usually susceptible in vitro to trimethoprim; however, high-level resistance (HLR) (MICs, >1,024 microg/ml) has been reported. We studied Enterococcus faecalis DEL, for which the trimethoprim MIC was >1,024 microg/ml. No transfer of resistance was achieved by broth or filter matings. Two different genes that conferred trimethoprim resistance when they were cloned in Escherichia coli (MICs, 128 and >1,024 microg/ml) were studied. One gene that coded for a polypeptide of 165 amino acids (MIC, 128 microg/ml for E. coli) was identical to dfr homologs that we cloned from a trimethoprim-susceptible E. faecalis strain, and it is presumed to be the intrinsic E. faecalis dfr gene (which causes resistance in E. coli when cloned in multiple copies); this gene was designated dfrE. The nucleotide sequence 5' to this dfr gene showed similarity to thymidylate synthetase genes, suggesting that the dfr and thy genes from E. faecalis are located in tandem. The E. faecalis gene that conferred HLR to trimethoprim in E. coli, designated dfrF, codes for a predicted polypeptide of 165 amino acids with 38 to 64% similarity with other dihydrofolate reductases from gram-positive and gram-negative organisms. The nucleotide sequence 5' to dfrF did not show similarity to the thy sequences. A DNA probe for dfrF hybridized under high-stringency conditions only to colony lysates of enterococci for which the trimethoprim MIC was >1,024 microg/ml; there was no hybridization to plasmid DNA from the strain of origin. To confirm that this gene causes trimethoprim resistance in enterococci, we cloned it into the integrative vector pAT113 and electroporated it into RH110 (E. faecalis OG1RF::Tn916DeltaEm) (trimethoprim MIC, 0.5 microg/ml), which resulted in RH110 derivatives for which the trimethoprim MIC was >1, 024 microg/ml. These results indicate that dfrF is an acquired but probably chromosomally located gene which is responsible for in vitro HLR to trimethoprim in E. faecalis.

Amino Acid Sequence↗
PubMed1999

In vitro activities of two ketolides, HMR 3647 and HMR 3004, against gram-positive bacteria.

The in vitro activities of two new ketolides, HMR 3647 and HMR 3004, were tested by the agar dilution method against 280 strains of gram-positive bacteria with different antibiotic susceptibility profiles, including Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Streptococcus spp. (group A streptococci, group B streptococci, Streptococcus pneumoniae, and alpha-hemolytic streptococci). Seventeen erythromycin-susceptible (EMs), methicillin-susceptible S. aureus strains were found to have HMR 3647 and HMR 3004 MICs 4- to 16-fold lower than those of erythromycin (MIC at which 50% of isolates were inhibited [MIC50] [HMR 3647 and HMR 3004], 0.03 microgram/ml; range, 0.03 to 0.06 microgram/ml; MIC50 [erythromycin], 0.25 microgram/ml; range, 0.25 to 0.5 microgram/ml). All methicillin-resistant S. aureus strains tested were resistant to erythromycin and had HMR 3647 and HMR 3004 MICs of > 64 micrograms/ml. The ketolides were slightly more active against E. faecalis than against E. faecium, and MICs for individual strains varied with erythromycin susceptibility. The MIC50s of HMR 3647 and HMR 3004 against Ems enterococci (MIC < or = 0.5 microgram/ml) and those enterococcal isolates with erythromycin MICs of 1 to 16 micrograms/ml were 0.015 microgram/ml. E. faecalis strains that had erythromycin MICs of 128 to > 512 micrograms/ml showed HMR 3647 MICs in the range of 0.03 to 16 micrograms/ml and HMR 3004 MICs in the range of 0.03 to 64 micrograms/ml. In the group of E. faecium strains for which MICs of erythromycin were > or = 512 micrograms/ml, MICs of both ketolides were in the range of 1 to 64 micrograms/ml, with almost all isolates showing ketolide MICs of < or = 16 micrograms/ml. The ketolides were also more active than erythromycin against group A streptococci, group B streptococci, S. pneumoniae, rhodococci, leuconostocs, pediococci, lactobacilli, and diphtheroids. Time-kill studies showed bactericidal activity against one strain of S. aureus among the four strains tested. The increased activity of ketolides against gram-positive bacteria suggests that further study of these agents for possible efficacy against infections caused by these bacteria is warranted.

Anti-Bacterial Agents↗
PubMed1998

Recurrent group B streptococcal disease in infants: Who should receive rifampin?

A preterm breast-fed infant had three episodes of type Ia/c group B streptococcus septicemia. After the second episode rifampin was given to the infant, but further Ia/c exposure to maternal breast milk ensued. We propose rifampin treatment for both the mother and infant in cases of recurrent group B streptococcus disease.

Breast Feeding↗
PubMed1998

In vivo testing of an Enterococcus faecalis efaA mutant and use of efaA homologs for species identification.

Disruption of the previously described efaA (from Enterococcus faecalis antigen A) gene was generated in E. faecalis strain OG1RF and loss of an 37-kDa immunoreactive band from the mutant was demonstrated in Western blots. In a mouse peritonitis model, mice infected with the efaAfs (fs=from Enterococcus faecalis) mutant showed more prolonged survival than mice infected with the parent strain OG1RF. These results suggest that efaAfs encodes a function important for infection of mice by enterococci. An efaA-like gene was also identified in E. faecium DNA libraries and its deduced amino acid sequence showed 73% similarity to EfaA of E. faecalis and 42-63% similarities to a group of streptococcal virulence and adhesion associated proteins that are components of ATP-binding cassette transport systems. Intragenic probes representing efaAfs, recAfs, efaAfm (fm=from E. faecium) and gyrAfm were tested for their ability to identify E. faecalis and E. faecium using colony lysates of 133 enterococci and one Streptococcus sp. Probes of E. faecium and E. faecalis origin hybridized to all isolates of E. faecium and E. faecalis, respectively, regardless of their clinical source but not to any of 29 other enterococci. These results suggest that the use of gene probes may prove helpful in identification of isolates of E. faecium and E. faecalis.

Amino Acid Sequence↗
PubMed1996

Comparative in-vitro activity of the new fluoroquinolone trovafloxacin (CP-99,219) against gram-positive cocci.

The in-vitro activities of the new fluoroquinolone trovafloxacin (CP-99,219) and ciprofloxacin were determined against 225 Gram-positive cocci. Trovafloxacin was 4-32 fold more active than ciprofloxacin against staphylococci and streptococci and also showed greater activity against enterococci including vancomycin resistant Enterococcus faecium and Enterococcus faecalis that were highly resistant to aminoglycosides and/or produced beta-lactamase. Trovafloxacin was also bactericidal at 3 mg/L against enterococci except for isolates for which the MICs were > or = 2 mg/L.

Anti-Infective Agents↗
PubMed1996

Vancomycin-resistant enterococci from nosocomial, community, and animal sources in the United States.

The presence of vancomycin-resistant enterococci (VRE) was looked for in fecal samples from 104 healthy volunteers (3 with hospital exposure), 100 selected hospitalized patients, and various environmental sources (44 commercial chickens, 5 farm-raised chickens, 3 turkeys, and 2 chicken farm lagoon slurries). Five probiotic preparations were also studied. No VRE with vanA or vanB genes were isolated from the healthy volunteers without hospital exposure, environmental sources, or probiotic preparations. VRE with vanB were found in the stools of 16% of the high-risk hospitalized patients and in one volunteer with hospital contact. All VRE examined could be classified into one of two clones by pulsed-field gel electrophoresis. VRE from 11 of the colonized patients were quantified and ranged from 10(3) to 10(6) CFU/g of stool. This study, in contrast to findings in Europe, failed to find evidence of VanA- or VanB-type VRE in the community or environmental sources in Houston, Texas, and suggests that these settings are not a likely source of VRE in hospitals in this geographic area.

Adolescent↗