PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Enterococcus faecalis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,387 records · Page 77Linked to original sources

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1997). I. Susceptibility distribution].

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 560 bacterial strains isolated from patients with urinary tract infections (UTIs) in 9 hospitals during the period of June 1997 to May 1998. Of the above bacterial isolates, Gram-positive bacteria accounted for 29.3% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 70.7% and most of them were Escherichia coli. Susceptibilities of several isolated bacteria to antimicrobial agents were as followed; 1. Enterococcus faecalis Ampicillin (ABPC) showed the highest activity against E. faecalis isolated from patients with UTIs. Its MIC90 was 1 microgram/ml. Imipenem (IPM) and vancomycin (VCM) were also active with the MIC90s of 2 micrograms/ml. The others had low activities with the MIC90s of 16 micrograms/ml or above. 2. Staphylococcus aureus including MRSA VCM and arbekacin (ABK) showed the highest activities against both S. aureus and MRSA isolated from patients with UTIs. The MIC90s of them were 1 microgram/ml. The others except minocycline (MINO) had low activities with the MIC90s of 32 micrograms/ml or above. More than a half of S. aureus strains (including MRSA) showed high susceptibilities to gentamicin (GM) and MINO, the MIC50s of 0.25 microgram/ml or 0.5 microgram/ml. 3. Enterobacter cloacae IPM showed the highest activity against E. cloacae. The MICs for all strains were equal to or lower than 1 microgram/ml. The MIC90s of ciprofloxacin (CPFX) and tosufloxacin (TFLX) were 1 microgram/ml, the MIC90s of amikacin (AMK) and ofloxacin (OFLX) were 4 micrograms/ml, the MIC90 of GM was 16 micrograms/ml. Among E. cloacae strains, those with low susceptibilities to quinolones have decreased in 1997, compared with those in 1996. But the other drugs were not so active in 1997 as 1996. 4. Escherichia coli All drugs except penicillins were active against E. coli with the MIC90s of 8 micrograms/ml or below. Particularly, flomoxef (FMOX), cefmenoxime (CMX), cefpirome (CPR), cefozopran (CZOP), IPM, CPFX and TFLX showed the highest activities against E. coli with the MIC90s of 0.125 microgram/ml or below. 5. Klebsiella pneumoniae K. pneumoniae was susceptible to almost all the drugs except penicillins. Carumonam (CRMN) had the strongest activity with the MICs for all strains equal to or lower than 0.125 microgram/ml. FMOX, CPR, CZOP, CPFX and TFLX were also active with the MIC90s of 0.125 microgram/ml or below. The MIC90s of quinolones had changed into a better state in 1997, compared with those in 1996. 6. Proteus mirabilis Almost all the drugs except ABPC and MINO showed high activities against P. mirabilis. CMX, ceftazidime (CAZ), latamoxef (LMOX), CPR, cefixime (CFIX), cefpodoxime (CPDX) and CRMN showed the highest activities against P. mirabilis. The MICs of them for all strains were equal to or lower than 0.125 microgram/ml. CPFX and TFLX were also active with the MIC90s of 0.125 microgram/ml or below. 7. Pseudomonas aeruginosa The MIC90 of GM was 8 micrograms/ml, the MIC90s of AMK, IPM and meropenem (MEPM) were 16 micrograms/ml. The others were not so active against P. aeruginosa with the MIC90s of 32 micrograms/ml or above. The MIC90s of quinolones had changed into a lower state in 1997, compared with those in 1996. 8. Serratia marcescens IPM showed the highest activity against S. marcescens. Its MIC90 was 2 micrograms/ml. GM was also active with the MIC90 of 4 micrograms/ml. The MIC90s of the others were 16 micrograms/ml or above. The MIC50s of CRMN was 0.125 microgram/ml or below, the MIC50s of CPR and CZOP were 0.25 microgram/ml.

Anti-Bacterial Agents↗

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1996). I. Susceptibility distribution].

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 680 bacterial strains isolated from patients with urinary tract infections (UTIs) in 10 hospitals during the period of June 1996 to May 1997. Of the above bacterial isolates, Gram-positive bacteria accounted for 30.4% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 69.6% and most of them were Escherichia coli. Susceptabilities of several isolated bacteria to antimicrobial agents were as followed; 1. Enterococcus faecalis Ampicillin (ABPC) showed the highest activity against E. faecalis isolated from patients with UTIs. Its MIC90 was 1 microgram/ml. Imipenem (IPM) and vancomycin (VCM) were also active with the MIC90S of 2 micrograms/ml. The others had low activities with the MIC90S of 16 micrograms/ml or above. 2. Staphylococcus aureus including MRSA Arbekacin (ABK) and VCM showed the highest activities against both S. aureus and MRSA isolated from patients with UTIs. The MIC90S of them were 1 or 2 micrograms/ml. The others except minocycline (MINO) had low activities with the MIC90S of 32 micrograms/ml or above. 3. Staphylococcus epidermidis ABK and VCM showed the strongest activities against S. epidermis isolated from patients with UTIs. The MICs for all strains were equal to or lower than 2 micrograms/ml. Cefazolin (CEZ), cefotiam (CTM) and cefozopran (CZOP) were also active with the MIC90S of 4 micrograms/ml. Compared with antimicrobial activities of cephems is 1995, the MIC90S of them had changed into a better state. They ranged from 4 micrograms/ml 16 micrograms/ml in 1996. 4. Streptococcus agalactiae All drugs except MINO were active against S. agalactiae. ABPC, CZOP, IPM, and clarithromycin (CAM) showed the highest activities. The MICs for all strains were equal to or lower than 0.125 micromilligrams. Tosufloxacin (TFLX) and VCM were also active with the MIC90S of 0.5 micromilligrams. 5. Citrobacter freundii Gentamicin (GM) showed the highest activity against C. freundii isolated from patients with UTIs. Its MIC90 was 0.5 micrograms/ml. IPM and amikacin (AMK) were also active with the MIC90S of 1 microgram/ml and 2 micrograms/ml, respectively. Cefpirome (CPR) and CZOP were also active with the MIC90S of 8 micrograms/ml. The MIC90S of the others were 16 micrograms/ml or above. 6. Enterobacter cloacae IPM showed the highest activity against E. cloacae. The MICs for all strains were equal to or lower than 0.5 microgram/ml. The MIC90S of ciprofloxacin (CPFX) and TFLX were 1 microgram/ml, the MIC90 of AMK was 2 micrograms/ml, the MIC90S of CZOP, GM and ofloxacin (OFLX) were 4 micrograms/ml. The MIC50S of cephems except CEZ, cefmetazole (CMZ) and cefaclor (CCL) had changed into a better state in 1996, compared with those in 1995. 7. Escherichia coli All drugs except penicillins and MINO were active against E. coli. Particularly CPR, CZOP and IPM showed the highest activities against E. coli. The MIC90S of them were 0.125 microgram/ml or below. Among E. coli strains, those with low susceptibilities to cephems except CEZ, cefoperazone (CPZ), latamoxef (LMOX) and CCL have increased in 1996, compared with those in 1995. 8. Klebsiella pneumoniae K. pneumoniae was susceptible to all drugs except penicillins, with the MIC90S of 2 micrograms/ml or below. CPR had the strongest activity, the MICs for all strains were equal to or lower than 0.25 microgram/ml. Flomoxef (FMOX), cefixime (CFIX), CZOP and carumonam (CRMN) were also active with the MIC90S of 0.125 microgram/ml or below. 9. Pseudomonas aeruginosa All drugs except quinolones were not so active against P. aeruginosa with the MIC90S were 32 micrograms/ml or above. Quinolones were more active in 1996 than 1995. The MIC90S of them were between 4 micrograms/ml and 8 micrograms/ml, and the MIC50S of them were between 1 microgram/ml and 2 micrograms/ml. 10. Serratia marcescens GM showed the highest activity against S. marcescens. Its MIC90 was 1 micro

Anti-Bacterial Agents↗

Measurement of ampicillin, vancomycin, linezolid and gentamicin activity against enterococcal biofilms.

BACKGROUND: Enterococci frequently cause biofilm infections but susceptibility of clinical isolates growing in biofilms has not been investigated. The minimum biofilm eradicating concentration (MBEC) has been suggested as a guide to treatment of biofilm infections. We measured an alternative endpoint, the minimum biofilm inhibitory concentration (MBIC) and compared the results with MIC and MBC. OBJECTIVES: To compare the MIC, MBC and MBIC of ampicillin, vancomycin and linezolid against enterococcal biofilms, to assess the impact of additional gentamicin and correlate findings with clinical outcome. METHODS: MIC and MBC were measured using standard techniques. MBICs were measured using a modification of the Calgary biofilm device method. Fifty-eight enterococcal isolates from episodes of intravascular catheter-related bloodstream infection were tested. RESULTS: Tolerance to ampicillin, vancomycin and linezolid was seen in 93%, 100% and 93% of isolates, respectively. MIC(90)s of ampicillin, vancomycin and linezolid were all 4 mg/L for Enterococcus faecalis isolates. MBC(90)s of ampicillin, vancomycin and linezolid for E. faecalis isolates were 1024, >128 and 2048 mg/L, respectively. MBIC(90)s of ampicillin, vancomycin and linezolid for E. faecalis isolates were 8192, 4096 and 4096 mg/L, respectively. Results for Enterococcus faecium were similar for vancomycin and linezolid but this species was generally more resistant to ampicillin. Adding 10 mg/L gentamicin had a variable effect on MIC, MBC or MBIC, which was not predictable by gentamicin susceptibility on disc testing. CONCLUSIONS: Very high concentrations of ampicillin, vancomycin and linezolid are required to inhibit enterococcal biofilms in vitro. Combining these agents with gentamicin significantly reduced MIC, MBC and MBIC against only a proportion of enterococcal isolates. No correlation between MBIC and outcome was found.

Acetamides↗

Simple combined agar-strip test for detection of enterococcal susceptibility to ampicillin, moderate- or high-level gentamicin resistance and potential additive activity of ampicillin plus gentamicin.

A simple combined agar-strip test (CAST), involving filter paper strips charged with 20 micrograms of ampicillin or 40 micrograms of gentamicin, accurately detected high-level gentamicin resistance among 43 of 146 isolates of Enterococcus faecalis and additive activity of ampicillin plus gentamicin against 101 of 103 (98%) isolates of E. faecalis with moderate-level gentamicin resistance (MLGR). All 15 MLGR Enterococcus faecium isolates were moderately to highly resistant to ampicillin; 5 isolates with moderate resistance to ampicillin (minimal inhibitory concentrations = 16 micrograms/ml) were additively inhibited by ampicillin plus gentamicin, whereas the highly ampicillin-resistant E. faecium isolates yielded an indifferent effect with the CAST procedure.

Ampicillin↗

Microbiological characteristics of "androlla", a Spanish traditional pork sausage.

Counts of total aerobic mesophilic microflora, lactic acid bacteria, salt-tolerant microflora, Enterobacteriaceae, enterococci, moulds and yeasts, and staphylococci, and some physico-chemical parameters (total solids, NaCl and nitrate contents and pH and aw values) were determined in 20 units of "androlla", a traditional dry-fermented sausage made in the NW of Spain. In general, high counts of all the investigated microbial groups were observed, with average values of 8.99 +/- 0.46 log cfu/g for the total aerobic mesophilic microflora, 9.11 +/- 0.16 log cfu/g for the lactic acid bacteria, 6.87 +/- 0.68 log cfu/g for the salt-tolerant microflora, 2.80+/-1.85 log cfu/g for the Enterobacteriaceae, 3.25 +/- 1.86 log cfu/g for the enterococci, 4.30 +/- 1.73 log cfu/g for the moulds and yeasts, and 3.62 +/- 0.60 log cfu/g for the staphylococci. From MRS agar, SPC agar + 7.5% NaCl, VRBG agar, and KAA agar, 10 colonies were randomly taken from each androlla unit and from each culture medium. A total of 200 strains per culture medium were then identified using the classical methods. Among the isolates from MRS agar, Lactobacillus sakei predominated, followed by Lactobacillus curvatus, Lactobacillus alimentarius and Lactobacillus plantarum. Of the 200 isolates obtained from SPC agar + 7.5% NaCl, only 56 strains belonged to the Staphylococcaceae or Micrococcaceae families. Among the Staphylococcaceae, Staphylococcus xylosus was the main species, followed by Staph. epidermidis; Staph. equorum, Staph. capitis and Staph. saprophyticus were isolated in very low proportions. Among the Micrococcaceae, Micrococcus luteus predominated, followed by Micrococcus lylae, Kocuria varians and Kocuria kristinae. Of the 150 isolates obtained from VRBG agar, Hafnia alvei was the main species, followed by Serratia liquefaciens and Enterobacter amnigenus; six isolates were identified as Salmonella. Among the 190 isolates obtained from KAA agar, 122 were considered enterococci; 20 isolates were identified as Enterococcus faecium, one as Enterococcus faecalis and 101 as Enterococcus inter faecalis-faecium.

Animals↗

Conjugal transfer of plasmid DNA from Escherichia coli to enterococci: a method to make insertion mutations.

Shuttle vector pAT18 was transferred by conjugation from Escherichia coli S17-1 to Enterococcus faecalis OG1RF and Enterococcus faecium SE34. Transfer was mediated by the transfer functions of plasmid RK2 in E. coli S17-1 and the origin of conjugal transfer (oriT) located on pAT18. The oriT sequence was then inserted into two plasmids to generate vectors pTEX5235 and pTEX5236. These two vectors cannot replicate in gram-positive bacteria and can be used to make insertion mutants in gram-positive bacteria. An internal sequence from an autolysin gene of E. faecalis OG1RF was cloned into pTEX5235 and transferred by conjugation from E. coli S17-1 to E. faecalis OG1RF. The plasmid was found to integrate into the chromosome of OG1RF by a single crossover event, resulting in a disrupted autolysin gene. A cosmid carrying the pyrimidine gene cluster from E. faecalis, with a transposon insertion in pyrC, was also transferred from E. coli S17-1 to E. faecalis OG1RF. After selection for the transposon, it was found to have recombined into the recipient chromosome by a double crossover between the cosmid and the chromosome of OG1RF. This resulted in a pyrC knockout mutant showing an auxotrophic phenotype.

Conjugation, Genetic↗

Variable phenotypes of enterocolitis in interleukin 10-deficient mice monoassociated with two different commensal bacteria.

BACKGROUND & AIMS: To explore the hypothesis that selective immune responses to distinct components of the intestinal microflora induce intestinal inflammation, we characterized disease kinetics and bacterial antigen-specific T-cell responses in ex germ-free interleukin 10 -/- and wild-type control mice monoassociated with Enterococcus faecalis , Escherichia coli , or Pseudomonas fluorescens . METHODS: Colitis was measured by using blinded histological scores and spontaneous interleukin 12 secretion from colonic strip culture supernatants. Interferon gamma secretion was measured from mesenteric or caudal lymph node CD4 + T cells stimulated with bacterial lysate-pulsed antigen-presenting cells. Luminal bacterial concentrations were measured by culture and quantitative polymerase chain reaction. RESULTS: Escherichia coli induced mild cecal inflammation after 3 weeks of monoassociation in interleukin 10 -/- mice. In contrast, Enterococcus faecalis-monoassociated interleukin 10 -/- mice developed distal colitis at 10-12 weeks that was progressively more severe and associated with duodenal inflammation and obstruction by 30 weeks. Neither bacterial strain induced inflammation in wild-type mice, and germ-free and Pseudomonas fluorescens-monoassociated interleukin 10 -/- mice remained disease free. CD4 + T cells from Enterococcus faecalis- or Escherichia coli-monoassociated interleukin 10 -/- mice selectively produced higher levels of interferon gamma and interleukin 4 when stimulated with antigen-presenting cells pulsed with the bacterial species that induced disease; these immune responses preceded the onset of histological inflammation in Enterococcus faecalis -monoassociated mice. Luminal bacterial concentrations did not explain regional differences in inflammation. CONCLUSIONS: Different commensal bacterial species selectively initiate immune-mediated intestinal inflammation with distinctly different kinetics and anatomic distribution in the same host.

Animals↗

Emergence of vancomycin-resistant enterococci in a tertiary hospital in Crete, Greece: a cluster of cases and prevalence study on intestinal colonisation.

The aim of this study was to investigate the clinical and epidemiological characteristics of five consecutive cases of infection with vancomycin-resistant enterococci (VRE) and the prevalence of faecal carriage of VRE among patients admitted to a 700-bed university hospital where no VRE had been isolated previously. In a 2-month period, five consecutive patients infected with VRE were detected. Three VanB+ Enterococcus faecium isolates were obtained from three patients, while two VanA+ E. faecium isolates, one VanA+ Enterococcus faecalis isolate and one VanC1+ Enterococcus gallinarum isolate were obtained from the other two patients. Of 218 faecal specimens from all hospital wards, 41 (18.8%) were found to contain VRE. Forty-two isolates of VRE were obtained, comprising one (2%) E. faecalis, 11 (27%) E. faecium, 24 (57%) E. gallinarum and six (14%) Enterococcus casseliflavus/flavescens. Four isolates carried the vanA gene, eight carried vanB, 24 carried vanC1, and six carried vanC2/C3. Use of glycopeptides, the presence of central venous catheters and renal dialysis all correlated with VRE colonisation. The prevalence rates were among the highest reported in the literature.

Adult↗

Division of the genus Enterococcus into species groups using PCR-based molecular typing methods.

Broad-range 16S rDNA PCR (BR-PCR) applied to DNA from 32 clinical enterococcal isolates and 12 other enterococci from a clinical reference collection followed by species-specific hybridization analysis identified 25 strains of Enterococcus faecalis and 19 Enterococcus species. Randomly amplified polymorphic DNA (RAPD) analysis using UPGMA clustering on the same material revealed four different clusters at a similarity level of 49%. Based on partial 16S rDNA sequence analysis of variable regions V4 and V9, it was possible to divide the 19 type strains specifying the genus Enterococcus into 12 different 16S rDNA species groups. The type strain distribution then served as a template for the analysis of the other 44 strains which were assigned to four different species groups (a-d) based on their 16S rDNA motifs. There was good agreement with the RAPD clusters. Species group a was an individual species line containing 25 strains that were identified as E. faecalis. Group b also represented an individual species line of 12 strains identified as E. faecium. The remaining seven strains that formed species groups c and d could not be fully identified to species by this analysis. It was concluded that BR-PCR of 16S rDNA followed by partial sequence analysis of the PCR products is a reliable technique for the identification and classification of enterococci. Further division of unresolved species groups should be achievable if regions other than V4 and V9 of 16S rDNA are also analysed.

Bacterial Typing Techniques↗

[Post-marketing surveillance of antibacterial activities of cefozopran against various clinical isolates--I. Gram-positive bacteria].

As a post-marketing surveillance, the in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates were yearly evaluated and compared with those of other cephems, oxacephems, penicillins, and carbapenems. Changes in the bacterial sensitivity for CZOP were also evaluated with the resistance ratio calculated with breakpoint MIC. Sixteen species (1,913 strains) of Gram-positive bacteria were isolated from the clinical materials annually collected from 1996 to 2000, and consisted of methicillin-susceptible Staphylococcus aureus (MSSA; n = 178), methicillin-resistant S. aureus (MRSA; n = 199), methicillin-susceptible Staphylococcus epidermidis (MSSE; n = 98), methicillin-resistant S. epidermidis (MRSE; n = 164), Staphylococcus haemolyticus (n = 72), Staphylococcus saprophyticus (n = 28), Enterococcus faecalis (n = 206), Enterococcus faecium (n = 91), Enterococcus avium (n = 72), Streptococcus pyogenes (n = 133), Streptococcus agalactiae (n = 138), penicillin-susceptible Streptococcus pneumoniae (PSSP; n = 133), penicillin-intermediate resistant S. pneumoniae (PISP; n = 100), penicillin-resistant S. pneumoniae (PRSP; n = 29), Streptococcus milleri group (n = 135) and Peptostreptococcus spp. (n = 137). CZOP possessed comparable antibacterial activities against MSSA and MSSE to other cephems, and was also effective on MRSE but not on MRSA. An antibacterial activity of CZOP against S. saprophyticus was comparable to or higher than other cephems. CZOP, however, did not indicate an antibacterial activity against S. haemolyticus, just like other cephems. An antibacterial activity of CZOP against E. faecalis was comparable to cefpirome (CPR) and higher than other cephems. No antibacterial activity of CZOP against E. faecium and E. avium was observed, just like other drugs. An antibacterial activity of CZOP against S. pyogenes was as potent as that of cefotiam (CTM), cefepime (CFPM) and CPR, and that against S. agalactiae was also preferable. CZOP and other cephems also had a preferable antibacterial activity against S. milleri group that was most sensitive to benzylpenicillin. An antibacterial activity of CZOP against Peptostreptococcus spp. was preferable but weaker than that of cefazolin, CTM and cefmetazole. The resistance ratio estimated with breakpoint MIC of CZOP was 96.5% in MRSA, 93.1% in PRSP, 60.0% in PISP, 40.3% in S. haemolyticus, 22.3% in E. faecalis, and 15.9% in MRSE. Those resistance ratios were similar to those for CFPM, but E. faecalis showed 90.8% resistance for CFPM. The difference in the resistance ratio of E. faecalis demonstrated that CZOP successfully maintained its antibacterial activity against this species. In conclusion, no remarkable annual change in the antibacterial activities of CZOP against the Gram-positive bacteria was observed. The sensitivities of PISP and PRSP to CZOP, however, was suggested to be decreasing.

Cephalosporins↗

[Enterococcal endocarditis: clinical and microbiological features of our series].

Of 81 cases of infectious endocarditis seen at our institution from 1988 to 1995, 61 had positive culture (75%) and, of these, 10 (16%) were caused by enterococcal strains (9 by Enterococcus faecalis, 1 by Enterococcus faecium). The 10 cases consisted of 5 native valve endocarditis and 5 late prosthetic valve endocarditis. Median age of patients was 50 years (range 21-58); 6, were males. Diagnostic or surgical procedures on the abdomen, genito-urinary tract, or chest preceded the onset of fever in almost all cases. Nine enterococcal strains showed low-level resistance to aminoglycosides and one was highly resistant. Seven patients were treated with ampicillin and gentamicin and 2 with teicoplanin and gentamicin. The patient, whose infection was caused by an high gentamicin-resistant E. faecalis, was treated with the combination of ciprofloxacin and cotrimoxazole chosen on the basis of the in vitro susceptibility tests. Congestive heart failure occurred in 4 patients and major embolic events in 3. All patients were cured; 4, with medical therapy alone and 6, with antimicrobials associated with surgical substitution of the valve. The data indicate that enterococcal endocarditis, when treated with appropriate antimicrobial regimens, associated with surgical treatment when necessary, has a very low mortality rate. The conventional treatment, -lactams plus gentamicin is usually effective. However, for high-level gentamicin-resistant strains alternative treatments must be selected on the basis of the in vitro susceptibility tests.

English Abstract↗

Whole-Genome Sequencing of Feline Uropathogens Reveals Multidrug Resistance and Zoonotic Potential in Domestic Cats in Tunisia.

BACKGROUND: Urinary tract infections (UTIs) in cats are increasingly recognized as clinically relevant conditions frequently associated with multidrug-resistant (MDR) bacteria of potential zoonotic origin, yet genomic data on feline uropathogens remain scarce in Tunisia. METHODS: We used whole-genome sequencing to characterize seven bacterial isolates recovered from six cats with clinical signs of UTI: Mammaliicoccus lentus (n = 2), Staphylococcus schleiferi (n = 1), Mammaliicoccus sciuri (n = 1), Enterococcus faecalis (n = 1), Enterococcus casseliflavus (n = 1), and Klebsiella aerogenes (n = 1). RESULTS: Resistome analysis revealed determinants conferring resistance to β-lactams (blaZ, blaCMY-132), methicillin (mecC-type), macrolides (erm(43), ermB), tetracyclines (tet(M), tet(45), tetB), fosfomycins (fosI, fosB, fosA5), and aminoglycosides (aac(6'), aph(3')-IIIa, aph(6)-Id), alongside efflux pump genes (efrA, sepA, sdrM, oqxA, KpnE/F/G), vancomycin-operon genes (vanT, vanY, vanC, vanG), and biofilm/biocide-tolerance genes (salB, qacG). Notably, M. lentus S104 carried mecC-type elements, the first such report in Tunisia, while K. aerogenes displayed an extensive MDR profile, including blaCMY-132 and fosA5. Multilocus sequence typing/ribosomal multilocus sequence typing (MLST/rMLST) identified diverse lineages, including the internationally distributed E. faecalis ST19 and the rarely reported K. aerogenes ST242. Plasmids were absent in all isolates; a Tn916/1545-type transposon occurred in E. casseliflavus, and clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems were unevenly distributed. CONCLUSIONS: These findings highlight companion animals as reservoirs of clinically important resistance genes, reinforcing the need for One Health AMR surveillance.

Animals↗

New derivatives of benzimidazole and their antimicrobial activity.

Azolium salts and neutral 2-aryl derivatives of benzimidazole, benzothiazole and benzoxazole were synthesized and compounds were identified by 1H and 13C NMR spectroscopy and microanalytical methods. In this work the salts 1 and the neutral compounds 2 were evaluated for their in vitro antimicrobial activity against standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Candida albicans and Candida tropicals. The compounds 1f, 1g, 1l, 1m, 1n, 2a, 2b, 2c, 2e, 2f showed antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Candida albicans and Candida tropicals, with minimum inhibitory concentrations (MICs) ranging between 50 to 200 mg/mL. Compounds 1f, 1g, 1l, lm, 2b, 2c showed the highest activity. Benzothiazolium and benzoxazolium salts were more active than 1,3-disubstituted benzimidazolium salts and neutral 2-substituted benzimidazole, benzothiazole and benzoxazole derivatives.

Anti-Bacterial Agents↗

Comparison of three methods for the molecular typing of Singapore isolates of enterococci with high-level aminoglycoside resistances.

Enterococci are frequently isolated as nosocomial pathogens and have often acquired intrinsic drug resistances. Molecular typing techniques have been developed to assist in epidemological and infection control measures. This study investigates enterococci with high-level aminoglycoside resistance (HLAR) from the National University Hospital (NUH) of Singapore, and evaluates and compares three methods for typing: restriction enzyme analysis by conventional gel electrophoresis [restriction fragment length polymorphism (RFLP)], pulsed-field gel electrophoresis (PFGE), and polymerase chain reaction (PCR) using random amplified polymorphic DNA (RAPD). Fifty-two isolates of Enterococcus faecalis and 13 isolates of Enterococcus faecium were used for the study. The numbers of patterns obtained for E. faecalis and E. faecium were 26 and 4, respectively by the RFLP method, and very similar discrimination was obtained by PFGE. RAPD PCR results were not reliably reproducible. A single pattern type by RFLP accounted for 16 of the E. faecalis isolates, suggesting hospital spread.

Aminoglycosides↗

Antimicrobial activity of everninomicin against clinical isolates of Enterococcus spp., Staphylococcus spp., and Streptococcus spp. tested by Etest.

The in-vitro antimicrobial activity of everninomicin, a novel oligosaccharide antibiotic, was tested against clinical isolates of 11 methicillin-susceptible Staphylococcus aureus (MSSA) strains, 11 methicillin-resistant S. aureus (MRSA) strains, 22 Staphylococcus epidermidis strains, 23 Enterococcus faecalis strains, 23 Enterococcus faecium strains, 23 Enterococcus avium strains, 27 Streptococcus pneumoniae strains, 22 Streptococcus pyogenes strains, and 20 Streptococcus agalactiae strains. The minimum inhibitory concentrations (MICs) of everninomicin were determined by Etest and compared with those of vancomycin, teicoplanin, and minocycline. The Etest showed that everninomicin exhibited excellent activity (MIC, <0.016 to 1.5 microg/ml) against the gram-positive cocci tested. The antimicrobial activity of everninomicin against S. aureus and S. epidermidis was stronger than that of vancomycin, teicoplanin, and minocycline, in particular against MRSA, with an MIC50 of 0.38 microg/ml and an MIC90 of 0.5 microg/ml. Against strains of enterococci and streptococci, everninomicin was more active than vancomycin, but as active as teicoplanin.

Aminoglycosides↗

Vancomycin-resistant enterococci isolated from animals and food.

One hundred and one chicken products, boiled ham and turkey cold meat were acquired from 18 different supermarkets in Spain during October 1997 to June 1998 and were analyzed for vancomycin-resistant enterococci (VRE). In the same way, 50 intestinal chicken samples from a slaughterhouse were also studied. VRE were detected in 25 of 92 samples of food of chicken origin (27.2%), but no VRE were found in cooked pork or turkey products. VRE were also detected in 8 of 50 intestinal chicken samples from the slaughterhouse (16%). VRE were identified as Enterococcus durans (n = 11), Enterococcus faecalis (n = 10), Enterococcus faecium (n = 10) and Enterococcus hirae (n = 2). All these strains were characterized as belonging to the vanA genotype by polymerase chain reaction. Ampicillin, quinupristin/dalfopristin and high level aminoglycoside resistance were frequently found among these strains. Heterogeneity was observed in susceptibility patterns among VRE strains, even in those of the same species. The high rate of colonization of chicken products by vanA containing enterococci detected 6 months to 1 year after the banning of avoparcin as a growth promoter, supports other studies suggesting that the food chain could be a source of VRE colonization in humans and thus a source of VRE infections.

Animals↗

The in vitro activity of daptomycin against 514 Gram-positive aerobic clinical isolates.

The in vitro activity of daptomycin was assessed in comparison with that of vancomycin and penicillin against a wide range of Gram-positive aerobic clinical isolates. MICs were determined by an agar dilution method on Mueller-Hinton agar (NCCLS/EUCAST) and on Isotonic agar adjusted to contain 50 mg/L free calcium (BSAC). Both media were enriched with 5% horse blood for fastidious organisms. Daptomycin MICs for all 172 staphylococci, including methicillin-susceptible and methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus, were 0.03-0.5 mg/L. For 99 of the 100 enterococci (Enterococcus faecalis, n = 50; Enterococcus faecium, n = 50), including 37 vancomycin-resistant isolates, they were 0.25-2 mg/L. For all 108 beta-haemolytic streptococci, including Streptococcus pyogenes and Streptococcus agalactiae, daptomycin MICs were 0.016- 0.25 mg/L; for 101 alpha-haemolytic streptococci, including Streptococcus pneumoniae and 'viridans' streptococci, they were 0.016-2 mg/L. For miscellaneous vancomycin-resistant isolates including Lactobacillus spp., Lactococcus spp., Leuconostoc spp., Pediococcus spp. and isolates of Enterococcus casseliflavus and Enterococcus gallinarum, daptomycin MICs were 0.03-2 mg/L; MICs for the seven isolates of Listeria monocytogenes were 0.25-4 mg/L. There was little difference between the results on Mueller-Hinton agar and on supplemented Isotonic agar The discrepant results occasionally obtained tended to be one dilution higher on supplemented Isotonic agar. Daptomycin was active (MICs < or = 2 mg/L) against all the isolates tested with the exception of one isolate each of E. faecium and L. monocytogenes (MICs = 4 mg/L). Our results indicate that daptomycin MICs are independent of methicillin and vancomycin MICs.

Anti-Bacterial Agents↗

High occurrence of esp among ampicillin-resistant and vancomycin-susceptible Enterococcus faecium clones from hospitalized patients.

The ability to colonize patients successfully may be essential for the emergence and spread of resistant nosocomial strains. We determined the presence of Esp, a surface protein involved in colonization ability in Enterococcus faecalis, in 96 Enterococcus faecium isolates from hospitalized patients (77 PFGE clones), 33 faecal isolates from healthy volunteers (32 clones) and 20 environmental isolates (20 clones). Esp was found significantly more often in E. faecium isolated from hospitalized patients than in isolates from the community setting (26% versus 6%, P < 0.01) and was significantly more common among ampicillin-resistant than among ampicillin-susceptible strains (37% versus 4%, P < 0.001), regardless of the isolation site. The frequency of the esp gene in the hospital clearly correlates with antibiotic-resistant E. faecium clones. This observation indicates that antibiotic-resistant variants may frequently arise under antibiotic selective pressure among esp-positive clones reaching ecological abundance in the nosocomial habitat.

Ampicillin Resistance↗