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Enterococci
Kinds of Enterococci Terms modified by Enterococci Selected AbstractsHIGH PREVALENCE OF EXTENDED-SPECTRUM ,-LACTAMASES ESCHERICHIA COLI AND VANCOMYCIN-RESISTANT ENTEROCOCCI ISOLATES FROM CHICKEN PRODUCTS.JOURNAL OF FOOD SAFETY, Issue 1 2010A PROBLEM OF PUBLIC HEALTH ABSTRACT Twenty-nine chicken products were acquired from different supermarkets in Portugal during September to December 2007 and were analyzed for extended-spectrum ,-lactamases (ESBL) Escherichia coli and vancomycin-resistant enterococci (VRE). Cefotaxime-resistant E. coli isolates were recovered in 27 of 29 chicken samples representing 93% of the analyzed samples. The highest percentages of resistance (more than 50% of the isolates) were detected for ampicillin, nalidixic acid and tetracycline. VRE isolates were detected in 17 of 29 samples of chicken origin (59%) and were identified as Enterococcus durans (n = 15) and E. faecium (n = 2) with the highest percentages of resistance being detected for erythromycin, tetracycline, ampicillin and ciprofloxacin. Seven E. durans and the two E. faecium isolates recovered from chicken wings, gizzard and skin show gelatinase activity. The high rate of colonization of chicken products by these bacteria supports other studies suggesting that the food chain could be a source of ESBL and VRE colonization in humans representing a public health problem. PRACTICAL APPLICATIONS The data indicate that chicken products may be contaminated with a high prevalence of extended-spectrum ,-lactamases Escherichia coli and vancomycin-resistant enterococci (VRE). It is important to mention that the isolates present a diversity of phenotypes of antimicrobial resistance, and half of the VRE isolates show also gelatinase activity, indicating that these animals may be a reservoir of bacteria showing virulence and increased resistance to antimicrobial agents, raising special concerns about their transmission to humans through the food chain. [source] EPIDEMIOLOGY AND CONTROL OF VANCOMYCIN-RESISTANT ENTEROCOCCI (VRE) IN A RENAL UNITNEPHROLOGY, Issue 3 2000MacGinley R [source] Structural organization of a complex family of palindromic repeats in EnterococciFEMS MICROBIOLOGY LETTERS, Issue 1 2009Eliana De Gregorio Abstract Enterococcus faecalis/faecium repeats (EFARs) are miniature insertion sequences spread in the genome of Enterococcus faecalis and Enterococcus faecium. Unit-length repeats measure 165,170 bp and contain two modules (B and T) capable of folding independently into stem-loop sequences, connected by a short, unstructured module J. The E. faecalis elements feature only one type of B, J and T modules. In contrast, the E. faecium elements result from the assembly of different types of B, J and T modules, and may vary in length because they carry multiple B modules. Most EFARs are located close (0,20 bp) to ORF stop codons, and are thus cotranscribed with upstream flanking genes. In both E. faecalis and E. faecium cells, EFAR transcripts accumulate in a strand-dependent fashion. Data suggest that T modules function as bidirectional transcriptional terminators, which provide a 3,-end to gene transcripts spanning B modules, while blocking antisense transcripts coming in from the opposite direction. [source] Mechanisms of antimicrobial resistance and genetic relatedness among enterococci isolated from dogs and cats in the United StatesJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010C.R. Jackson Abstract Aims:, In this study, mechanisms of antimicrobial resistance and genetic relatedness among resistant enterococci from dogs and cats in the United States were determined. Methods and Results:, Enterococci resistant to chloramphenicol, ciprofloxacin, erythromycin, gentamicin, kanamycin, streptomycin, lincomycin, quinupristin/dalfopristin and tetracycline were screened for the presence of 15 antimicrobial resistance genes. Five tetracycline resistance genes [tet(M), tet(O), tet(L), tet(S) and tet(U)] were detected with tet(M) accounting for approx. 60% (130/216) of tetracycline resistance; erm(B) was also widely distributed among 96% (43/45) of the erythromycin-resistant enterococci. Five aminoglycoside resistance genes were also detected among the kanamycin-resistant isolates with the majority of isolates (25/36; 69%) containing aph(3,)-IIIa. The bifunctional aminoglycoside resistance gene, aac(6,)-Ie -aph(2,)-Ia, was detected in gentamicin-resistant isolates and ant(6)-Ia in streptomycin-resistant isolates. The most common gene combination among enterococci from dogs (n = 11) was erm(B), aac(6,)-Ie- aph(2,)-Ia, aph(3,)-IIIa, tet(M), while tet(O), tet(L) were most common among cats (n = 18). Using pulsed-field gel electrophoresis (PFGE), isolates clustered according to enterococcal species, source and antimicrobial gene content and indistinguishable patterns were observed for some isolates from dogs and cats. Conclusion:, Enterococci from dogs and cats may be a source of antimicrobial resistance genes. Significance and Impact of the Study:, Dogs and cats may act as reservoirs of antimicrobial resistance genes that can be transferred from pets to people. Although host-specific ecovars of enterococcal species have been described, identical PFGE patterns suggest that enterococcal strains may be exchanged between these two animal species. [source] Antilisterial activity of lactic acid bacteria isolated from rigouta, a traditional Tunisian cheeseJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2004T. Ghrairi Abstract Aims:, Screening for lactic acid bacteria (LAB) producing bacteriocins and other antimicrobial compounds is of a great significance for the dairy industry to improve food safety. Methods and Results:, Six-hundred strains of LAB isolated from ,rigouta', a Tunisian fermented cheese, were tested for antilisterial activity. Eight bacteriocinogenic strains were selected and analysed. Seven of these strains were identified as Lactococcus lactis and produced nisin Z as demonstrated by mass spectrometry analysis of the purified antibacterial compound. Polymerase chain reaction experiments using nisin gene-specific primers confirmed the presence of nisin operon. Plasmid profiles analysis suggests the presence of, at least, three different strains in this group. MMT05, the eighth strain of this antilisterial collection was identified, at molecular level, as Enterococcus faecalis. The purified bacteriocin produced by this strain showed a molecular mass of 10 201·33 ± 0·85 Da. This new member of class III bacteriocins was termed enterocin MMT05. Conclusions:, Seven lactococcal strains producing nisin Z were selected and could be useful as bio-preservative starter cultures. Additional experiments are needed to evaluate the promising strain MMT05 as bio-preservative as Enterococci could exert detrimental or beneficial role in foods. Significance and Impact of the Study:, Only a few antibacterial strains isolated from traditional African dairy products were described. The new eight strains described herein contribute to the knowledge of this poorly studied environment and constitute promising strains for fermented food safety. [source] Characterization of yellow-pigmented and motile enterococci isolated from intestines of the garden snail Helix aspersaJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002Aims: Enterococci associated with garden snails (Helix aspersa) were studied in order to obtain reliable species identification and characterization. Methods and Results: Twelve yellow-pigmented and motile enterococci, isolated from the intestines of garden snails, were phenotypically close to Enterococcus casseliflavus, but they showed certain unusual biochemical characteristics. tRNA intergenic length polymorphism analysis (tDNA-PCR) divided all strains studied into two groups, in full agreement with biochemical test results. 16S rDNA sequencing, DNA base composition analysis and DNA-DNA hybridization results showed unambiguously that the enterococci studied belonged to the species Ent. casseliflavus. The representative strains of described ecovars were deposited in the Czech Collection of Microorganisms (CCM) as Ent. casseliflavus CCM 4868, 4869, 4870 and 4871. Conclusions:Enterococcus casseliflavus associated with garden snails can be subdivided into groups. Significance and Impact of the Study:Enterococcus casseliflavus differs from other enterococcal species in that it is typically associated with plants, soil, water and invertebrate animals. The different groups that can be found in these widely occurring bacteria are possibly source-specific ecovars, as exemplified by the Ent. casseliflavus inhabiting the intestines of snails. [source] Safety and Functional Aspects of Preselected Enterococci for Probiotic Use in Iberian Dry-Fermented SausagesJOURNAL OF FOOD SCIENCE, Issue 7 2009Santiago Ruiz-Moyano ABSTRACT:, The purpose of this study was to investigate enterococci for potential probiotic use in Iberian dry-fermented sausages. A total of 15 strains isolated from Iberian dry-fermented sausages, human feces, and pig feces were evaluated for their safety and functional characteristics including biogenic amine (BA) production, antibiotic susceptibility, hemolysis, virulence determinants, cell adhesion, and antimicrobial activity against foodborne pathogens. The strain,Enterococcus faecium,SE906 was able to establish itself on the intestinal epithelium, inhibiting such pathogenic bacteria as,Listeria monocytogenes in vitro. This strain was also considered safe to be used for its low aminogenic potential, and its antibiotic resistance pattern and virulence determinants, being identified as a potential probiotic meat starter culture suitable for manufacture of dry-fermented Iberian sausages. [source] Virulence, phenotype and genotype characteristics of endodontic Enterococcus spp.MOLECULAR ORAL MICROBIOLOGY, Issue 1 2005C. M. Sedgley Background/aims:, Enterococci have been implicated in persistent root canal infections but their role in the infection process remains unclear. This study investigated the virulence, phenotype and genotype of 33 endodontic enterococcal isolates. Methods:, Phenotypic tests were conducted for antibiotic resistance, clumping response to pheromone, and production of gelatinase, hemolysin and bacteriocin. Genotype analysis involved polymerase chain reaction amplification of virulence determinants encoding aggregation substances asa and asa373, cytolysin activator cylA, gelatinase gelE, gelatinase-negative phenotype ef1841/fsrC, adherence factors esp and ace, and endocarditis antigen efaA. Physical DNA characterization involved pulsed-field gel electrophoresis of genomic DNA, and plasmid analysis. Results:, Potential virulence traits expressed included production of gelatinase by Enterococcus faecalis (n = 23), and response to pheromones in E. faecalis culture filtrate (n = 16). Fourteen strains produced bacteriocin. Five strains were resistant to tetracycline and one to gentamicin, whereas all were susceptible to ampicillin, benzylpenicillin, chloramphenicol, erythromycin, fusidic acid, kanamycin, rifampin, streptomycin and vancomycin. Polymerase chain reaction products encoding efaA, ace, and asa were detected in all isolates; esp was detected in 20 isolates, cylA in six isolates, but asa373 was never detected. The gelatinase gene (gelE) was detected in all isolates of E. faecalis (n = 31) but not in Enterococcus faecium (n = 2); a 23.9 kb deletion sequence corresponding to the gelatinase-negative phenotype was detected in six of the eight E. faecalis isolates that did not produce gelatinase. Pulsed-field gel electrophoresis and plasmid analyses revealed genetic polymorphism with clonal types evident. Plasmid DNA was detected in 25 strains, with up to four plasmids per strain and a similar (5.1 kb) plasmid occurring in 16 isolates. Conclusions:, Phenotypic and genotypic evidence of potential virulence factors were identified in endodontic Enterococcus spp., specifically production of gelatinase and response to pheromones. [source] Infectious complications after kidney transplantation: current epidemiology and associated risk factorsCLINICAL TRANSPLANTATION, Issue 4 2006George J Alangaden Abstract:, Background:, The impact of newer immunosuppressive and antimicrobial prophylactic agents on the pattern of infectious complications following kidney transplantation has not been well studied. Methods:, This is an observational study in 127 adult recipients transplanted from 2001 to 2004. Patients received thymoglobulin (ATG) (50%) or basiliximab (50%) for induction and were maintained on mycophenolate mofetil, either tacrolimus (73%) or sirolimus (SRL) (27%), and prednisone (79%). Antimicrobial prophylaxis included perioperative cefazolin, trimethoprim/sulfamethaxazole for six months, valganciclovir for three months and nystatin for two months. Regression models were used to examine the association of various factors with infections. Results:, We observed 127 infections in 65 patients, consisting of urinary tract infection (UTI) (47%), viral infections (17%), pneumonia (8%) and surgical wound infections (7%). UTI was the most common infection in all post-transplant periods. Enterococcus spp. (33%) and Escherichia coli (21%) were the most prevalent uropathogens. Of six patients with cytomegalovirus infection, none had tissue-invasive disease. There were no cases of pneumocystis pneumonia or BK nephropathy. Six patients developed fungal infections. Two deaths due to disseminated Rhizopus and Candida albicans accounted for a 1.5% infection-related mortality. Retransplantation and ureteral stents were independently associated with UTI (OR = 4.5 and 2.9, p = 0.06 and 0.03, respectively), as were ATG and SRL with bacterial infections (OR = 3.3 and 2.5, p = 0.009 and 0.047, respectively). Conclusion:, This study suggests that the use of newer immunosuppressive agents in recent years is associated with some changes in the epidemiology of post-transplant infections. Enterococci have become the predominant uropathogen. Invasive fungal infections, although rare, are often fatal. [source] Cutaneous infections in the elderly: diagnosis and managementDERMATOLOGIC THERAPY, Issue 3 2003Jeffrey M. Weinberg ABSTRACT:, Over the past several years there have been many advances in the diagnosis and treatment of cutaneous infectious diseases. This review focuses on the three major topics of interest in the geriatric population: herpes zoster and postherpetic neuralgia (PHN), onychomycosis, and recent advances in antibacterial therapy. Herpes zoster in adults is caused by reactivation of the varicella-zoster virus (VZV) that causes chickenpox in children. For many years acyclovir was the gold standard of antiviral therapy for the treatment of patients with herpes zoster. Famciclovir and valacyclovir, newer antivirals for herpes zoster, offer less frequent dosing. PHN refers to pain lasting ,2 months after an acute attack of herpes zoster. The pain may be constant or intermittent and may occur spontaneously or be caused by seemingly innocuous stimuli such as a light touch. Treatment of established PHN through pharmacologic and nonpharmacologic therapy will be discussed. In addition, therapeutic strategies to prevent PHN will be reviewed. These include the use of oral corticosteroids, nerve blocks, and treatment with standard antiviral therapy. Onychomycosis, or tinea unguium, is caused by dermatophytes in the majority of cases, but can also be caused by Candida and nondermatophyte molds. Onychomycosis is found more frequently in the elderly and in more males than females. There are four types of onychomycosis: distal subungual onychomycosis, proximal subungual onychomycosis, white superficial onychomycosis, and candidal onychomycosis. Over the past several years, new treatments for this disorder have emerged which offer shorter courses of therapy and greater efficacy than previous therapies. The treatment of bacterial skin and skin structure infections in the elderly is an important issue. There has been an alarming increase in the incidence of gram-positive infections, including resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and drug-resistant pneumococci. While vancomycin has been considered the drug of last defense against gram-positive multidrug-resistant bacteria, the late 1980s saw an increase in vancomycin-resistant bacteria, including vancomycin-resistant enterococci (VRE). More recently, strains of vancomycin-intermediate resistant S. aureus (VISA) have been isolated. Gram-positive bacteria, such as S. aureus and Streptococcus pyogenes are often the cause of skin and skin structure infections, ranging from mild pyodermas to complicated infections including postsurgical wound infections, severe carbunculosis, and erysipelas. With limited treatment options, it has become critical to identify antibiotics with novel mechanisms of activity. Several new drugs have emerged as possible therapeutic alternatives, including linezolid and quinupristin/dalfopristin. [source] Human enteric viruses in groundwater indicate offshore transport of human sewage to coral reefs of the Upper Florida KeysENVIRONMENTAL MICROBIOLOGY, Issue 4 2010J. Carrie Futch Summary To address the issue of human sewage reaching corals along the main reef of the Florida Keys, samples were collected from surface water, groundwater and coral [surface mucopolysaccharide layers (SML)] along a 10 km transect near Key Largo, FL. Samples were collected semi-annually between July 2003 and September 2005 and processed for faecal indicator bacteria (faecal coliform bacteria, enterococci and Clostridium perfringens) and human-specific enteric viruses (enterovirus RNA and adenovirus DNA) by (RT)-nested polymerase chain reaction. Faecal indicator bacteria concentrations were generally higher nearshore and in the coral SML. Enteric viruses were evenly distributed across the transect stations. Adenoviruses were detected in 37 of 75 samples collected (49.3%) whereas enteroviruses were only found in 8 of 75 samples (10.7%). Both viruses were detected twice as frequently in coral compared with surface water or groundwater. Offshore, viruses were most likely to be found in groundwater, especially during the wet summer season. These data suggest that polluted groundwater may be moving to the outer reef environment in the Florida Keys. [source] Enterococcus faecalis with the gelatinase phenotype regulated by the fsr operon and with biofilm-forming capacity are common in the agricultural environmentENVIRONMENTAL MICROBIOLOGY, Issue 6 2009Lilia Macovei Summary The prevalence of gelatinase activity and biofilm formation among environmental enterococci was assessed. In total, 396 enterococcal isolates from swine and cattle faeces and house flies from a cattle farm were screened for gelatinase activity. The most prevalent phenotype on Todd,Hewitt agar with 1.5% skim milk was the weak protease (WP) (72.2% of isolates), followed by the strong protease (SP) 18.7%, and no protease (NP) (9.1%). The majority of WP isolates was represented by Enterococcus hirae (56.9%), followed by Enterococcus faecium (25.9%), Enterococcus casseliflavus (10.4%), Enterococcus gallinarum (5.2%) and Enterococcus saccharolyticus (1.7%). All WP isolates were negative for gelE (gelatinase) and sprE (serine protease) as well as the fsrABDC operon that regulates the two proteases, and only four isolates (7.0%) formed biofilms in vitro. All SP isolates were Enterococcus faecalis positive for the fsrABDC, gelE, sprE genes and the majority (91.2%) formed a biofilm. Diversity of NP isolates was relatively evenly distributed among E. hirae, E. faecium, E. casseliflavus, E. gallinarum, Enterococcus durans, E. saccharolyticus and Enterococcus mundtii. All NP isolates were negative for the fsr operon and only four E. hirae (11.1%) formed a biofilm. Of further interest was the loss of the gelatinase phenotype (18.9% of isolates) from SP isolates after 4 month storage at 4,8°C and several passages of subculture. Results of reverse transcription PCR analysis indicated that mRNA was produced for all the genes in the frs operon and sequencing of the gelE gene did not reveal any significant mutations. However, gelatinase was not detectable by Western blot analysis. Our study shows that E. faecalis with the complete fsr operon and the potential to form a biofilm are relatively common in the agricultural environment and may represent a source/reservoir of clinically relevant strains. In addition, many environmental enterococci, especially E. hirae, produce an unknown WP that can hydrolyse casein but does not contribute to biofilm formation. The stability of the gelatinase phenotype in E. faecalis and its regulation will require additional studies. [source] Bacterial population analysis of human colon and terminal ileum biopsies with 16S rRNA-based fluorescent probes: Commensal bacteria live in suspension and have no direct contact with epithelial cellsINFLAMMATORY BOWEL DISEASES, Issue 10 2005Laurens A van der Waaij PhD Abstract Background: The commensal intestinal microflora has important metabolic and perhaps also immune modulatory functions. Evidence has accumulated that the microflora plays a role in the pathogenesis of inflammatory bowel disease. Therefore, there is a growing interest in the intestinal microflora and its interaction with the host. Presumably, this interaction takes place at the mucus layer. In this study, we investigated the microflora that is present at the mucus layer and addressed the following questions. Does a specific mucus-adherent microflora exist? Is there direct contact between commensal bacteria and epithelial cells? Methods: Snap-frozen biopsies were taken of 5 colon regions and of the terminal ileum in 9 subjects with a normal colon. Fecal samples were also collected. Bacteria were detected in cryosections with fluorescent in situ hybridization (FISH) with 16S ribosomal (r)RNA-targeted probes for all bacteria and specific probes for the major representatives of anaerobic microflora (bifidobacteria, Bacteroides, clostridia, atopobia) and aerobic microflora (Enterobacteriaceae, enterococci, streptococci, lactobacilli). Results: With this sensitive technique, bacteria were only observed at the luminal side of the intestinal mucus layer. Very few microcolonies were present at the mucus layer, and the composition of the bacterial microflora present in the feces was similar to that at the mucus layer of the terminal ileum and colon regions. Conclusions: We did not observe direct contact between bacteria and epithelial cells. The equal distribution of bacterial species suggests that intestinal commensal bacteria live in suspension in the lumen and that there is no specific mucus-adherent microflora. [source] Technological characterization of the natural lactic acid bacteria of artisanal Turkish White Pickled cheeseINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 2 2008ELIF DAGDEMIR The aim of this study was to characterize the lactic acid bacteria (LAB) isolated from White Pickled cheeses produced with traditional methods; and to improve the quality of cheesemaking with a selection of bacterial cultures from artisanal White cheeses. LAB were isolated and identified from 30 White Pickled cheese samples collected from various cities in Turkey. Also, the numbers of several microbial groups (total aerobic mesophilic bacteria, LAB, enterococci, coliforms, moulds and yeasts) of cheese samples were enumerated. Lactobacilli, lactococci and enterococci were the most abundant microbial groups. The numbers of Enterococcus and Lactobacillus isolates were higher than those of the other LAB. Enterococcus faecalis (24.43%), Enterococcus faecium (17.61%) and Lactobacillus fermentum (19.88%) isolates were the most frequently isolated species. Lactococcus strains showed the highest acidifying activity, followed by Enterococcus and Lactobacillus strains. Proteolytic activity of Enterococcus faecalis strains was higher than that of the other enterococci species, except Enterococcus avium strains. Within lactobacilli strains, the highest mean proteolytic activity was that of Lactobacillus bifermentans, Lactobacillus brevis and Lactobacillus casei strains. [source] Systemic Inflammatory Response Syndrome in Nosocomial Bloodstream Infections with Pseudomonas aeruginosa and Enterococcus Species: Comparison of Elderly and Nonelderly PatientsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2006Alexandre R. Marra MD OBJECTIVES: To determine whether the systemic inflammatory response syndrome (SIRS), clinical course, and outcome of monomicrobial nosocomial bloodstream infection (BSI) due to Pseudomonas aeruginosa or Enterococcus spp. is different in elderly patients than in younger patients. DESIGN: Historical cohort study. SETTING: An 820-bed tertiary care facility. PARTICIPANTS: One hundred twenty-seven adults with P. aeruginosa or enterococcal BSI. MEASUREMENTS: SIRS scores were determined 2 days before the first positive blood culture through 14 days afterwards. Elderly patients (,65, n=37) were compared with nonelderly patients (<65, n=90). Variables significant for predicting mortality in univariate analysis were entered into a logistic regression model. RESULTS: No difference in SIRS was detected between the two groups. No significant difference was noted in the incidence of organ failure, 7-day mortality, or overall mortality between the two groups. Univariate analysis revealed that Acute Physiology And Chronic Health Evaluation (APACHE) II score of 15 or greater at BSI onset; adjusted APACHE II score (points for age excluded) of 15 or greater at BSI onset; and respiratory, cardiovascular, renal, hematological, and hepatic failure were predictors of mortality. Age, sex, use of empirical antimicrobial therapy, and infection with imipenem-resistant P. aeruginosa or vancomycin-resistant enterococci did not predict mortality. Multivariate analysis revealed that hematological failure (odds ratio (OR)=8.1, 95% confidence interval (CI)=2.78,23.47), cardiovascular failure (OR=4.7, 95% CI=1.69,13.10), and adjusted APACHE II , 15 at BSI onset (OR=3.1, 95% CI=1.12,8.81) independently predicted death. CONCLUSION: Elderly patients did not differ from nonelderly patients with respect to severity of illness before or at the time of BSI. Elderly patients with pseudomonal or enterococcal BSIs did not have a greater mortality than nonelderly patients. [source] Antimicrobial Resistance and Aging: Beginning of the End of the Antibiotic Era?JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2002Thomas T. Yoshikawa MD Throughout the history of mankind, infectious diseases have remained a major cause of death and disability. Although industrialized nations, such as the United States, have experienced significant reductions in infection-related mortality and morbidity since the beginning of the "antibiotic era," death and complications from infectious diseases remain a serious problem for older persons. Pneumonia is the major infection-related cause of death in older persons, and urinary tract infection is the most common bacterial infection seen in geriatric patients. Other serious and common infections in older people include intra-abdominal sepsis, bacterial meningitis, infective endocarditis, infected pressure ulcers, septic arthritis, tuberculosis, and herpes zoster. As a consequence, frequent prescribing of antibiotics for older patients is common practice. The large volume of antibiotics prescribed has contributed to the emergence of highly resistant pathogens among geriatric patients, including methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci, and multiple-drug-resistant gram-negative bacilli. Unless preventive strategies coupled with newer drug development are established soon, eventually clinicians will be encountering infections caused by highly resistant pathogens for which no effective antibiotics will be available. Clinicians could then be experiencing the same frustrations of not being able to treat infections effectively as were seen in the "pre-antibiotic era." [source] Mechanisms of antimicrobial resistance and genetic relatedness among enterococci isolated from dogs and cats in the United StatesJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010C.R. Jackson Abstract Aims:, In this study, mechanisms of antimicrobial resistance and genetic relatedness among resistant enterococci from dogs and cats in the United States were determined. Methods and Results:, Enterococci resistant to chloramphenicol, ciprofloxacin, erythromycin, gentamicin, kanamycin, streptomycin, lincomycin, quinupristin/dalfopristin and tetracycline were screened for the presence of 15 antimicrobial resistance genes. Five tetracycline resistance genes [tet(M), tet(O), tet(L), tet(S) and tet(U)] were detected with tet(M) accounting for approx. 60% (130/216) of tetracycline resistance; erm(B) was also widely distributed among 96% (43/45) of the erythromycin-resistant enterococci. Five aminoglycoside resistance genes were also detected among the kanamycin-resistant isolates with the majority of isolates (25/36; 69%) containing aph(3,)-IIIa. The bifunctional aminoglycoside resistance gene, aac(6,)-Ie -aph(2,)-Ia, was detected in gentamicin-resistant isolates and ant(6)-Ia in streptomycin-resistant isolates. The most common gene combination among enterococci from dogs (n = 11) was erm(B), aac(6,)-Ie- aph(2,)-Ia, aph(3,)-IIIa, tet(M), while tet(O), tet(L) were most common among cats (n = 18). Using pulsed-field gel electrophoresis (PFGE), isolates clustered according to enterococcal species, source and antimicrobial gene content and indistinguishable patterns were observed for some isolates from dogs and cats. Conclusion:, Enterococci from dogs and cats may be a source of antimicrobial resistance genes. Significance and Impact of the Study:, Dogs and cats may act as reservoirs of antimicrobial resistance genes that can be transferred from pets to people. Although host-specific ecovars of enterococcal species have been described, identical PFGE patterns suggest that enterococcal strains may be exchanged between these two animal species. [source] Application of microbial source tracking methods in a Gulf of Mexico field settingJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2009A. Korajkic Abstract Aims:, Microbial water quality and possible human sources of faecal pollution were assessed in a Florida estuary that serves shellfishing and recreational activities. Methods and Results:, Indicator organisms (IO), including faecal coliforms, Escherichia coli and enterococci, were quantified from marine and river waters, sediments and oysters. Florida recreational water standards were infrequently exceeded (6,10% of samples); however, shellfishing standards were more frequently exceeded (28%). IO concentrations in oysters and overlaying waters were significantly correlated, but oyster and sediment IO concentrations were uncorrelated. The human-associated esp gene of Enterococcus faecium was detected in marine and fresh waters at sites with suspected human sewage contamination. Lagrangian drifters, used to determine the pathways of bacterial transport and deposition, suggested that sediment deposition from the Ochlockonee River contributes to frequent detection of esp at a Gulf of Mexico beach. Conclusions:, These data indicate that human faecal pollution affects water quality in Wakulla County and that local topography and hydrology play a role in bacterial transport and deposition. Significance and Impact of the Study:, A combination of IO enumeration, microbial source tracking methods and regional hydrological study can reliably inform regulatory agencies of IO sources, improving risk assessment and pollution mitigation in impaired waters. [source] Prevalence, species distribution and antimicrobial resistance of enterococci isolated from dogs and cats in the United StatesJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2009C.R. Jackson Abstract Aims:, The contribution of dogs and cats as reservoirs of antimicrobial resistant enterococci remains largely undefined. This is increasingly important considering the possibility of transfer of bacteria from companion animals to the human host. In this study, dogs and cats from veterinary clinics were screened for the presence of enterococci. Methods and Results:, A total of 420 enterococci were isolated from nasal, teeth, rectal, belly and hindquarters sites of 155 dogs and 121 cats from three clinics in Athens, GA. Eighty per cent (124 out of 155) of the dogs and 60% (72 out of 121) of the cats were positive for enterococci. From the total number of dog samples (n = 275), 32% (n = 87) were from hindquarter, 31% (n = 86) were rectal, and 29% (n = 79) were from the belly area. The majority of isolates originated from rectal samples (53 out of 145; 37%) from cats. The predominant species identified was Enterococcus faecalis (105 out of 155; 68%) from dogs and E. hirae (63 out of 121; 52%) from cats. Significantly more E. faecalis were isolated from rectal samples than any other enterococcal species (P < 0·05) for both dogs and cats suggesting site specific colonization of enterococcal species. The highest levels of resistance were to ciprofloxacin in E. faecium (9 out of 10; 90%), chloramphenicol resistance in E. faecalis (17 out of 20; 85%) and gentamicin resistance in E. faecalis (19 out of 24; 79%) from dog samples and nitrofurantoin resistance in E. faecium (15 out of 19; 79%) from cats. Multi-drug resistance (MDR) (resistance ,2 antimicrobials) was observed to as few as two and as many as eight antimicrobials regardless of class. Conclusion:, This study demonstrated that dogs and cats are commonly colonized with antimicrobial resistant enterococci. Significance and Impact of the Study:, Dogs and cats may act as reservoirs of antimicrobial resistance genes that can be transferred from pets to people. [source] Evaluation of novel fluorogenic substrates for the detection of glycosidases in Escherichia coli and enterococciJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2006J.D. Perry Abstract Aims:, Enzyme substrates based on 4-methylumbelliferone are widely used for the detection of Escherichia coli and enterococci in water, by detection of , -glucuronidase and , -glucosidase activity respectively. This study aimed to synthesize and evaluate novel umbelliferone-based substrates with improved sensitivity for these two enzymes. Methods and Results:, A novel , -glucuronide derivative based on 6-chloro-4-methylumbelliferone (CMUG) was synthesized and compared with 4-methylumbelliferyl- , - d -glucuronide (MUG) using 42 strains of E. coli in a modified membrane lauryl sulfate broth. Over 7 h of incubation, the fluorescence generated from the hydrolysis of CMUG by E. coli was over twice that from MUG, and all of the 38 glucuronidase-positive strains generated a higher fluorescence with CMUG compared with MUG. Neither substrate caused inhibition of bacterial growth in any of the tested strains. Four , -glucosidase substrates were also synthesized and evaluated in comparison with 4-methylumbelliferyl- , - d -glucoside (MU-GLU) using 42 strains of enterococci in glucose azide broth. The four substrates comprised , -glucoside derivatives of umbelliferone-3-carboxylic acid and its methyl, ethyl and benzyl esters. Glucosides of the methyl, ethyl and benzyl esters of umbelliferone-3-carboxylic acid, were found to be superior to MU-GLU for the detection of enterococci, especially after 18 h of incubation, while umbelliferone-3-carboxylic acid- , - d -glucoside was inferior. However, the variability in detectable , -glucosidase activity among the different strains of enterococci in short-term assays using the three carboxylate esters (7 h incubation) may compromise their use for rapid detection and enumeration of these faecal indicator bacteria. Conclusions:, The , -glucuronidase substrate CMUG appears to be a more promising detection system than the various , -glucosidase substrates tested. Significance and Impact of the Study:, The novel substrate CMUG showed enhanced sensitivity for the detection of , -glucuronidase-producing bacteria such as E. coli, with a clear potential for application in rapid assays for the detection of this indicator organism in natural water and other environmental samples. [source] Occurrence of bacterial indicators and bacteriophages infecting enteric bacteria in groundwater in different geographical areasJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2006F. Lucena Abstract Aims:, The aim of this research was to determine the suitability of coliphages (bacteriophages) for assessing the microbial quality of groundwater. Methods and Results:, The number of several bacterial indicators (faecal coliforms, Escherichia coli, enterococci and spores of sulfite-reducing clostridia) and bacteriophages (somatic coliphages, F-specific RNA bacteriophages and bacteriophages infecting Bacteroides fragilis) were determined in groundwater of aquifers in various geographical areas. Results show that the relative abundance, determined as percentages of positive detections, of the bacterial indicators and bacteriophages varies depending on the aquifer. Conclusions:, A single bacterial indicator may not be enough to assess microbiological quality in certain aquifers. One bacterial indicator and a bacteriophage parameter provide more information than two bacterial indicators. Significance and Impact of the Study:, Coliphages (CPH) provide different information from that provided by bacterial indicators on the microbial quality of groundwater in different geographical areas. Easy, fast and inexpensive methods for the detection of CPH are feasible in both industrialized and developing countries. [source] Comparison of 16S rRNA sequencing with conventional and commercial phenotypic techniques for identification of enterococci from the marine environmentJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006D.F. Moore Abstract Aims:, To compare accuracy of genus and species level identification of presumptive enterococci isolates from the marine environment using conventional biochemical testing, four commercial identification systems and 16S rRNA sequence analysis. Methods and Results:, Ninety-seven environmental bacterial isolates identified as presumptive enterococci on mEI media were tested using conventional and Enterococcus genus screen biochemical tests, four commercial testing systems and 16S rRNA sequencing. Conventional and Enterococcus genus screen biochemical testing, 16S rRNA sequencing and two commercial test systems achieved an accuracy of ,94% for Enterococcus genus confirmation. Conventional biochemical testing and 16S rRNA sequencing achieved an accuracy of ,90% for species level identification. Conclusions:, For confirmation of Enterococcus genus from mEI media, conventional or genus screen biochemical testing, 16S rRNA sequencing and the four commercial systems were correct 79,100% of the time. For speciation to an accuracy of 90% or better, either conventional biochemical testing or 16S rRNA sequencing is required. Significance and Impact of the Study:, Accurate identification of presumptive environmental Enterococcus isolates to genus and species level is an integral part of laboratory quality assurance and further characterization of Enterococcus species from pollution incidents. This investigation determines the ability of six different methods to correctly identify environmental isolates. [source] Decrease of enteric micro-organisms from rural sewage sludge during their composting in straw mixtureJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2005A.-M. Pourcher Abstract Aims:, To study the decrease of enteric micro-organisms including viable nematode eggs, enteroviruses, faecal indicators (Escherichia coli and enterococci) and pathogenic bacteria (Listeria monocytogenes, Salmonella sp. and Clostridium perfringens) of a rural sewage sludge when it is composted for 7 months in mixture with straw. Methods and Results:, Numbers of the test organisms and the physico-chemical parameters were measured on a monthly basis on the mixture, on the compost after being turned, and on the pile in three positions representing the part by which air is incoming, the bottom of the pile and the part through which air is outgoing. The lowest temperature in the pile was observed at the bottom, where it did not exceed 50°C against 66°C in the two other areas. There were no significant differences between the three areas in terms of micro-organism survival. Infectious enteroviruses were inactivated rapidly and were not found after the first turning whereas some genomes were detected until after the third turning. Escherichia coli and enterococci presented a similar survival rate and their number decreased by 4 log10 whereas Salmonella decayed at a greater rate than L. monocytogenes. The numbers of C. perfringens decreased gradually to reach a final concentration in the mature compost of about 102 CFU g,1 dry matter (d.m.), which was similar to that of the faecal indicators. Conclusions:, The hygienic effect of sludge composting in mixture with straw results in a significant reduction of enteric micro-organisms, the concentration of the faecal indicators in the final product being <64 most probable number g,1 d.m. The concentrations of Salmonella, enteroviruses and viable nematode eggs in the final product were not detectable which is in accordance with the French legislation. Significance and Impact of the Study:, The results which pointed out the different behaviour of the test micro-organisms reflect the difficulty to propose a relevant indicator of hygienization. Otherwise, they show that composting is an efficient means for hygienization of sludge of rural wastewater treatment, where the straw is available close to their place of production. [source] Peracetic acid as an alternative wastewater disinfectant to chlorine dioxideJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002S. Stampi Aims: The aim of this study was to compare the efficiency of peracetic acid with that of chlorine dioxide in the disinfection of wastewater from a sewage treatment plant (serving about 650 000 inhabitants) that has been using peracetic acid as a disinfectant since 1998. Methods and Results: A total of 23 samplings were made, each consisting of three samples: from secondary effluent, effluent disinfected with 2 mg l,1 of peracetic acid and effluent disinfected with 2·2 mg l,1 of chlorine dioxide (contact time 20 min). For each sample, measurements were made of the heterotrophic plate count at 36°C, total and faecal coliforms, Escherichia coli, enterococci, pH, suspended solids and chemical oxygen demand (COD). During the first phase of the experiment the peracetic acid was seen to be less efficient than chlorine dioxide. To improve the disinfectant action a system of mechanical agitation was added which led to a greater efficiency in the inactivation of bacteria of faecal origin. Conclusions: Both products were found to be influenced by the level of microbial contamination, the amount of suspended solids and COD but not by the pH of the effluent before disinfection. The immediate mixing of the wastewater and disinfectant caused a greater reduction in enterococci. Significance and Impact of the Study: Since peracetic acid was seen to produce a high abatement of micro-organisms, it can be considered as a valid alternative to chlorine dioxide in the disinfection of wastewaters. [source] Microbial interaction in cooked cured meat products under vacuum or modified atmosphere at 4°CJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2002J. Metaxopoulos Aims: To investigate the antagonistic activity of two lactic acid strains against the spoilage microflora in cooked cured meat products, vacuum or modified atmosphere packed at 4°C and to determine the inhibitory capacity of their bacteriocins. Methods and Results: Frankfurter-type sausages and sliced cooked cured pork shoulder were inoculated with Leuconostoc mesenteroides L124 and Lactobacillus curvatus L442 or with their bacteriocins. The microbial, physico-chemical (pH, l - and d -lactate, acetate and ammonia) and colour changes were studied. Results under vacuum packaging showed that in the uninoculated samples of the pork product the spoilage microflora grew but in the inoculated ones the spoilage microorganisms (e.g. Brochothrix thermosphacta and enterococci) reduced during the storage. This observation was more pronounced in the samples with the addition of bacteriocins. In the frankfurter-type sausages the spoilage microflora did not grow in the uninoculated and inoculated samples. In the modified atmosphere enriched in CO2 the population of spoilage microflora remained at low levels in both products, indicating that CO2 has an effect on thespoilage microorganisms' growth. In the pork product the concentrations of acetate and d -lactate increased while l -lactate decreased, but in the frankfurter-type sausages increase of acetate and d -lactate was not observed. Conclusions: Lactic acid strains had an effect on the spoilage microflora growth but did not affect, negatively, the organoleptic properties of the products. These strains may be used as biopreservative cultures or their bacteriocins could be an important contribution to microbiological quality of meat products. Significance and Impact of Study: Establishment of biopreservation as a method for extension of shelf life of meat products. [source] Characterization of yellow-pigmented and motile enterococci isolated from intestines of the garden snail Helix aspersaJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002Aims: Enterococci associated with garden snails (Helix aspersa) were studied in order to obtain reliable species identification and characterization. Methods and Results: Twelve yellow-pigmented and motile enterococci, isolated from the intestines of garden snails, were phenotypically close to Enterococcus casseliflavus, but they showed certain unusual biochemical characteristics. tRNA intergenic length polymorphism analysis (tDNA-PCR) divided all strains studied into two groups, in full agreement with biochemical test results. 16S rDNA sequencing, DNA base composition analysis and DNA-DNA hybridization results showed unambiguously that the enterococci studied belonged to the species Ent. casseliflavus. The representative strains of described ecovars were deposited in the Czech Collection of Microorganisms (CCM) as Ent. casseliflavus CCM 4868, 4869, 4870 and 4871. Conclusions:Enterococcus casseliflavus associated with garden snails can be subdivided into groups. Significance and Impact of the Study:Enterococcus casseliflavus differs from other enterococcal species in that it is typically associated with plants, soil, water and invertebrate animals. The different groups that can be found in these widely occurring bacteria are possibly source-specific ecovars, as exemplified by the Ent. casseliflavus inhabiting the intestines of snails. [source] Characterization of lactic acid bacteria strains on the basis of neutral volatile compounds produced in wheyJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2001G. Mauriello G. MAURIELLO, L. MOIO, G. MOSCHETTI, P. PIOMBINO, F. ADDEO AND S. COPPOLA. 2001. Aims: Seventy-eight strains of lactic acid bacteria belonging to five genera and showing six different phenotype combinations of Lac (lactose fermentation), Prt (proteolytic activity) and Cit (citrate degradation) characters were investigated for their main flavouring properties with the aim to detect variability among and within the groups. Methods and Results: High resolution gas chromatography,mass spectrometry analysis of neutral volatile compounds produced in whey showed that, considering both neo-formation compounds and substances quantified in the whey cultures at different concentrations in comparison to the extract from sterile whey, the groups of lactococci, enterococci, thermophilic streptococci and mesophilic lactobacilli produced a higher number of volatiles than thermophilic lactobacilli and leuconostocs. Applying principal component analysis (PCA) to the results, enterococci, mesophilic lactobacilli and thermophilic streptococci showed a broad diversity, while lactococci included rather similar strains as well as strains with special flavouring properties. Applying PCA to thermophilic streptococci and enterococci, to lactococci and enterococci, to lactococci and thermophilic streptococci, or to mesophilic and thermophilic lactobacilli, the strains gathered consistently with their systematic position. Conclusions: The study evidenced strains producing some volatile compounds responsible for food flavouring. Flavouring properties were variable among the systematic groups and in some cases different within the same bacterial group. Significance and Impact of the Study: The potential of the findings is discussed with reference to the development of flavouring adjuncts for the dairy industry. [source] The fate of stormwater-associated bacteria in constructed wetland and water pollution control pond systemsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2000C.M. Davies The performances of a constructed wetland and a water pollution control pond were compared in terms of their abilities to reduce stormwater bacterial loads to recreational waters. Concentrations of thermotolerant coliforms, enterococci and heterotrophic bacteria were determined in inflow and outflow samples collected from each system over a 6-month period. Bacterial removal was significantly less effective in the water pollution control pond than in the constructed wetland. This was attributed to the inability of the pond system to retain the fine clay particles (< 2 µm) to which the bacteria were predominantly adsorbed. Sediment microcosm survival studies showed that the persistence of thermotolerant coliforms was greater in the pond sediments than in the wetland sediments, and that predation was a major factor influencing bacterial survival. The key to greater bacterial longevity in the pond sediments appeared to be the adsorption of bacteria to fine particles, which protected them from predators. These observations may significantly affect the choice of treatment system for effective stormwater management. [source] Seasonal, sexual and developmental differences in hoopoe Upupa epops preen gland morphology and secretions: evidence for a role of bacteriaJOURNAL OF AVIAN BIOLOGY, Issue 2 2009Manuel Martín-Vivaldi The uropygial glands of birds serve multiple functions, and there is great interspecific variability in the composition and properties of their secretions. A special case is the secretion in the hoopoes Upupa epops, and green woodhoopoes Phoeniculus purpureus, which, contrary to the commonly white and odourless secretions, are dark with pungent odour. Recently, bacteria have been isolated from glands of both woodhoopoes and hoopoes and here we test the hypothesis that bacteria are responsible of some of the special properties of glands and secretions of this group of birds. We explore natural seasonal changes and intersexual differences in the properties of hoopoe glands and secretions, check the natural occurrence of bacteria within secretions, and analyse the effect of experimental injection of antibiotics on uropygial gland properties. Male glands underwent no seasonal changes, and their secretions were invariably white and odourless, very similar to female glands outside the breeding season. However, in comparison to the uropygial gland of non-breeding females, those of incubating females showed a marked increase in size and volume of secretion produced, which became dark and pungent. All these parameters increased until the hatching date and returned to values similar to those in the prelaying phase towards the end of the nestling period. Nestling glands produced secretions similar to those of females in colour and odour. Gland size of both females and nestlings predicted the amount of secretion produced. Microscopic techniques confirmed the presence of bacteria at high density and in active division in all dark secretions examined. The antibiotic treatment significantly reduced the load of enterococci in nestling glands, did not affect size of glands, but diminished the volume of secretion, which was lighter in colour than that of control nestlings. In nesting females, the experimental injection of antibiotic affected some measurements of gland size and secretion colour. Because the experiment did not affect general health estimates (immunocompetence, body condition or growing) of nestlings, our results suggest that some of the special properties of hoopoe glands are mediated by the presence of symbiotic bacteria. [source] Genetic characterization of vancomycin-resistant enterococci isolates from wild rabbitsJOURNAL OF BASIC MICROBIOLOGY, Issue 5 2009Nicholas Figueiredo Abstract The presence of van A-containing E. faecium isolates was demonstrated in three of 77 faecal samples (3.9%) of wild rabbits recovered in Portugal. Enterococcal strains with intrinsic vancomycin resistance (van C-1 or van C-2/3 gene) were found in five (6.5%) and three (3.9%) faecal samples, respectively. The mechanisms of resistance for other antibiotics were studied in these vancomycin-resistant isolates. All van A strains showed resistance for tetracycline [with the presence of tet (L) gene, associated or not with tet (M) gene] and for erythromycin [with the presence of the erm (B) gene]. Two isolates were resistant to ciprofloxacin and one to ampicillin. Two van C-1 strains and one van C-2/3 strain were tetracycline resistant [containing the tet (M) gene associated with tet (L) gene] and erythromycin resistant [with erm (B) gene]. Two van C-1 and two van C-2/3 strains were also ciprofloxacin resistant and one van C-1 strain was, additionally, resistant to quinupristin-dalfopristin. The two remaining isolates (van C-1, van C-2/3) did not show resistance for any additional antibiotic. The intestinal tract of wild rabbits could be a reservoir of van A-containing enterococci. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||||||||