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1.
Sci Rep ; 9(1): 16561, 2019 11 12.
Article in English | MEDLINE | ID: mdl-31719601

ABSTRACT

Assam tea or Miang is a local name of Camellia sinensis var. assamica in northern Thailand. By the local wisdom, Assam tea leaves are used as the raw material in tea fermentation to produce "Fermented Miang" consumed by people in northern Thailand and the countries nearby. In this study, twenty-eight bacterial isolates were obtained from Assam tea leaf samples collected from Nan province, Thailand. Bacterial isolates were identified within 6 genera including Bacillus, Floricoccus, Kocuria, Lysinibacillus, Micrococcus and Staphylococcus. Among these, the strain ML061-4 shared 100.0 and 99.4% similarity of 16S rRNA and rpoB gene sequence with F. penangensis JCM 31735T, respectively. This is the first discovery of F. penangensis in Thailand. F. penangensis ML061-4 exhibited probiotic characteristics including lactic acid production (9.19 ± 0.10 mg/ml), antibacterial activities (Escherichia coli ATCC 25922 and E. coli O157:H7 DMST 12743), acid and bile salt tolerance (71.1 and 54.9%, respectively), autoaggregation (97.0%), coaggregation (66.0% with E. coli O157:H7), cell surface hydrophobicity (90.0%), bacterial adhesion (82.9% with Lactobacillus plantarum FM03-1), competitive inhibition (17.8% with E. coli O157:H7) and competitive exclusion (34.9% with E. coli O157:H7). Overall, the data suggested that F. penangensis ML061-4 had a great potential to be a probiotic.


Subject(s)
Bacterial Proteins/genetics , Camellia sinensis/microbiology , Genes, Bacterial , Probiotics/pharmacology , Sequence Analysis, DNA , Streptococcaceae/genetics , Bacterial Adhesion/drug effects , Hydrophobic and Hydrophilic Interactions , Lactic Acid/metabolism , Microbial Sensitivity Tests , Phylogeny , Streptococcaceae/drug effects , Streptococcaceae/isolation & purification , Streptococcaceae/ultrastructure
2.
Photodiagnosis Photodyn Ther ; 24: 102-108, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30240927

ABSTRACT

BACKGROUND: To our knowledge, there is a lack of evidence on the effect of Antimicrobial Photodynamic Therapy (aPDT) by the application of curcumin against complex biofilms of dental caries lesions. This study aimed to evaluate the viability, vitality, and acid metabolism of infected dentin caries microcosms treated with curcumin-mediated aPDT. METHODS: After microcosm biofilms growing anaerobically on bovine dentin disks immersed in McBain medium with 1% sucrose at 37 °C for 5 days, the biofilms were treated by the association of DMSO water solution or 600 µmol L-1 curcumin with 0, 37.5 or 75 J cm-2 blue LED (455 nm). Then, the colony-forming units (CFU) counts of total microorganisms, total streptococci, mutans streptococci, and total lactobacilli were determined by plating. The lactic acid concentration was analyzed by enzymatic spectrophotometry method, while the vitality of intact biofilms was evaluated by confocal laser scanning microscope (CLSM). Statistical analysis was performed by Kruskal Wallis and post-hoc Dunn's tests (P < 0.05). RESULTS: Curcumin alone did not affect the viability of microorganisms and the vitality of intact biofilms. However, 75 J cm-2 LED alone decreased the total microorganisms and total lactobacilli counts. The combination of curcumin and LED reduced significantly the counts of all microorganism groups and the vitality of intact biofilms. Differences were not observed between the lactic acid concentrations of distinct groups. CONCLUSIONS: Therefore, curcumin-mediated aPDT was effective in reducing the viability and the vitality of infected dentin caries microcosms, without interfering in their acidogenicity.


Subject(s)
Curcumin/pharmacology , Dental Caries/drug therapy , Dentin/drug effects , Photochemotherapy/methods , Photosensitizing Agents/pharmacology , Animals , Biofilms/drug effects , Cattle , Dentin/microbiology , Dose-Response Relationship, Drug , Lactic Acid/biosynthesis , Lactobacillaceae/drug effects , Microscopy, Confocal , Streptococcaceae/drug effects
3.
Digestion ; 97(2): 195-204, 2018.
Article in English | MEDLINE | ID: mdl-29316555

ABSTRACT

BACKGROUND: Gut dysbiosis associated with the use of proton-pump inhibitors (PPIs) has been found to lead to the occurrence of infectious and inflammatory adverse events. A longitudinal observational cohort study has demonstrated the heightened risk of death associated with PPI use. SUMMARY: We evaluated meta-analyses to determine the association between PPI use and infectious and inflammatory diseases. Meta-analyses showed that PPI use is a potential risk for the development of enteric infections caused by Clostridium difficile, as well as small intestinal bacterial overgrowth, spontaneous bacterial peritonitis, community-acquired pneumonia, hepatic encephalopathy, and adverse outcomes in inflammatory bowel disease. We also examined changes in the composition and function of the gut microbiota with the use of PPIs. PPI use significantly increased the presence of Streptococcaceae and Enterococcaceae, which are risk factors for C. difficile infection, and decreased that of Faecalibacterium, a commensal anti-inflammatory microorganism. Key Message: High-throughput, microbial 16S rRNA gene sequencing has allowed us to investigate the association between the gut microbiome and PPI use. Future prospective comparison studies are necessary to confirm this association, and to develop new strategies to prevent complications of PPI use.


Subject(s)
Clostridioides difficile/pathogenicity , Clostridium Infections/microbiology , Dysbiosis/microbiology , Gastrointestinal Microbiome/drug effects , Intestinal Diseases/microbiology , Proton Pump Inhibitors/adverse effects , Clostridioides difficile/genetics , Clostridioides difficile/isolation & purification , DNA, Bacterial/isolation & purification , Enterococcaceae/drug effects , Enterococcaceae/genetics , Enterococcaceae/isolation & purification , Faecalibacterium/drug effects , Faecalibacterium/genetics , Faecalibacterium/isolation & purification , Humans , Intestines/drug effects , Intestines/microbiology , Meta-Analysis as Topic , RNA, Ribosomal, 16S/genetics , Risk Factors , Sequence Analysis, DNA , Streptococcaceae/drug effects , Streptococcaceae/genetics , Streptococcaceae/isolation & purification
4.
Int J Antimicrob Agents ; 37(3): 235-9, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21295447

ABSTRACT

The aims of this study were to determine the in vitro activity profile of ceftobiprole, a pyrrolidinone cephalosporin, against a large number of bacterial pathogens and to propose zone diameter breakpoints for clinical categorisation according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) minimum inhibitory concentration (MIC) breakpoints. MICs of ceftobiprole were determined by broth microdilution against 1548 clinical isolates collected in eight French hospitals. Disk diffusion testing was performed using 30 µg disks according to the method of the Comité de l'Antibiogramme de la Société Française de Microbiologie (CA-SFM). The in vitro activity of ceftobiprole, expressed by MIC(50/90) (MICs for 50% and 90% of the organisms, respectively) (mg/L), was as follows: meticillin-susceptible Staphylococcus aureus, 0.25/0.5; meticillin-resistant S. aureus (MRSA), 1/2; meticillin-susceptible coagulase-negative staphylococci (CoNS), 0.12/0.5; meticillin-resistant CoNS, 1/2; penicillin-susceptible Streptococcus pneumoniae, ≤ 0.008/0.03; penicillin-resistant S. pneumoniae, 0.12/0.5; viridans group streptococci, 0.03/0.12; ß-haemolytic streptococci, ≤ 0.008/0.016; Enterococcus faecalis, 0.25/1; Enterococcus faecium, 64/128; Enterobacteriaceae, 0.06/32; Pseudomonas aeruginosa, 4/16; Acinetobacter baumannii, 0.5/64; Haemophilus influenzae, 0.03/0.12; and Moraxella catarrhalis, 0.25/0.5. According to the regression curve, zone diameter breakpoints could be 28, 26, 24 and 22 mm for MICs of 0.5, 1, 2 and 4 mg/L respectively. In conclusion, this study confirms the potent in vitro activity of ceftobiprole against many Gram-positive bacteria, including MRSA but not E. faecium, whilst maintaining a Gram-negative spectrum similar to the advanced-generation cephalosporins such as cefepime. Thus ceftobiprole appears to be well suited for the empirical treatment of a variety of healthcare-associated infections.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Enterobacteriaceae/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Streptococcaceae/drug effects , Disk Diffusion Antimicrobial Tests , Drug Resistance, Bacterial , France , Hospitals, Teaching , Humans , Microbial Sensitivity Tests
5.
Curr Med Res Opin ; 25(6): 1461-7, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19419343

ABSTRACT

OBJECTIVE: To determine the proportion of subjects with oropharyngeal streptococci resistant to either levofloxacin or azithromycin prior to and during antibacterial exposure, and to follow temporal changes in the proportion of resistant and susceptible isolates through 6 weeks post-exposure. This randomized, open-label, single-center study is registered with ClinicalTrials.gov (identifier: NCT00821782). RESEARCH DESIGN AND METHODS: A total of 143 healthy volunteers (levofloxacin, n = 71; azithromycin, n = 72) without antibacterial exposure in the previous 90 days received either levofloxacin 750 mg once daily for 5 days or azithromycin 500 mg once daily on day 1 and 250 mg once daily on days 2 through 5. Oropharyngeal cultures were obtained pre-exposure, at day 5, and at 2, 4, and 6 weeks post-dosing. Bacterial strains were identified and the minimum inhibitory concentrations for levofloxacin and azithromycin were determined. RESULTS: At study entry 117 streptococci were isolated from 72 subjects randomized to azithromycin and 53 (45.3%) were azithromycin-resistant. None of the 121 streptococci isolated from 71 subjects randomized to.levofloxacin were colonized by a levofloxacin-resistant microorganism prior to dosing. At the end of dosing, the number of subjects with resistant streptococci (S. mitis, S. salivarius, S. sanguis, or alpha streptococcus species [spp.]) increased in azithromycin-exposed subjects and resistant isolates remained through 6 weeks post-dosing. In contrast, a small number of levofloxacin-resistant streptococci were observed at the end of dosing but decreased by week 2 post-dosing and continued to decrease through the 6-week evaluation period (p < 0.001 azithromycin vs. levofloxacin for S. mitis, S. salivarius, S. sanguis and alpha streptococcus spp. at week 6). Limitations of this study included the fact that, since previous antibiotic use was self-reported, genetic typing was not done. The results of this study may not be completely generalizable, because subjects in this study received study drug under directly-observed conditions, thus ensuring compliance. CONCLUSIONS: Both antibacterial agents were well tolerated. Levofloxacin 750 mg administered for 5 days was associated with less microbial resistance than that observed with azithromycin in healthy subjects.


Subject(s)
Azithromycin/pharmacology , Drug Resistance, Multiple, Bacterial/physiology , Levofloxacin , Ofloxacin/pharmacology , Oropharynx/microbiology , Streptococcal Infections/microbiology , Adolescent , Adult , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Azithromycin/administration & dosage , Dose-Response Relationship, Drug , Drug Resistance, Multiple, Bacterial/drug effects , Female , Humans , Male , Microbial Sensitivity Tests , Microbial Viability/drug effects , Ofloxacin/administration & dosage , Oropharynx/drug effects , Streptococcaceae/drug effects , Streptococcaceae/physiology , Young Adult
6.
J Craniomaxillofac Surg ; 37(7): 392-7, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19473851

ABSTRACT

Hospital-acquired infections and antibiotic-resistant bacteria continue to be major health concerns worldwide. Particularly problematic is methicillin-resistant Staphylococcus aureus (MRSA) and its ability to cause severe soft tissue, bone or implant infections. First used by the Australian Aborigines, Tea tree oil and Eucalyptus oil (and several other essential oils) have each demonstrated promising efficacy against several bacteria and have been used clinically against multi-resistant strains. Several common and hospital-acquired bacterial and yeast isolates (6 Staphylococcus strains including MRSA, 4 Streptococcus strains and 3 Candida strains including Candida krusei) were tested for their susceptibility for Eucalyptus, Tea tree, Thyme white, Lavender, Lemon, Lemongrass, Cinnamon, Grapefruit, Clove Bud, Sandalwood, Peppermint, Kunzea and Sage oil with the agar diffusion test. Olive oil, Paraffin oil, Ethanol (70%), Povidone iodine, Chlorhexidine and hydrogen peroxide (H(2)O(2)) served as controls. Large prevailing effective zones of inhibition were observed for Thyme white, Lemon, Lemongrass and Cinnamon oil. The other oils also showed considerable efficacy. Remarkably, almost all tested oils demonstrated efficacy against hospital-acquired isolates and reference strains, whereas Olive and Paraffin oil from the control group produced no inhibition. As proven in vitro, essential oils represent a cheap and effective antiseptic topical treatment option even for antibiotic-resistant strains as MRSA and antimycotic-resistant Candida species.


Subject(s)
Anti-Infective Agents, Local/pharmacology , Bacterial Infections/drug therapy , Candidiasis/drug therapy , Cross Infection/drug therapy , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents, Local/chemistry , Cross Infection/prevention & control , Drug Resistance, Microbial , Drug Resistance, Multiple/drug effects , Humans , Microbial Sensitivity Tests , Oils, Volatile/chemistry , Plant Oils/chemistry , Single-Blind Method , Staphylococcaceae/drug effects , Streptococcaceae/drug effects
7.
J Dent ; 36(8): 600-5, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18502558

ABSTRACT

OBJECTIVES: Toothbrushes are rapidly contaminated with different microorganisms, which colonize the oral cavity and interdental spaces. This can represent a possible cause of infection or reinfection. In this study, the ozone experimental effect upon toothbrushes microflora was estimated microbiologically before and after saturation with ozone gas. METHODS: Fifty used toothbrushes coming from children and adults were entered our study. Microorganisms were enumerated and identified. Bristles from each brush were soaked in ozone saturated PBS solution for 5, 10, 15, 20 and 30 min and the total microbial population was reassessed. RESULTS: Counts of microorganisms isolated per brush varied between 10(2) and 10(7) CFU. Candida albicans was present in used toothbrushes. No obligate anaerobes were isolated. Members of Streptococcaceae family were regularly found (65.2%) belonging to the following species: Streptococcus pyogenes, S. mutans, S. mitis, S. oralis, S. sobrinus, S. viridans, S. salivarius, S. sanguis, Aerococcus viridans. A. viridans and S. mutans were more frequently isolated on children toothbrushes while Staphylococcus aureus and S. epidermidis were found on adults brushes. Escherichia coli, Pseudomonas sp. and Enterococcus sp., were also recovered. We found that the ozone treatment decreased gradually the microbial load. However, a bacterial re-growth was effective following short ozonation period. Decontamination was complete after an extended exposure to ozone for 30 min. CONCLUSIONS: Ozone application was found to remove the toothbrushes bristles microbiota following conventional brushing. Maximum decontamination efficacy of ozone treatment was observed after 30 min while exposure for short time periods seems to be inefficient which probably reflect the low dose of ozone used in this study.


Subject(s)
Bacteria/drug effects , Dental Disinfectants/therapeutic use , Ozone/therapeutic use , Toothbrushing/instrumentation , Adult , Aged , Candida albicans/drug effects , Child , Colony Count, Microbial , Enterococcus/drug effects , Escherichia coli/drug effects , Humans , Middle Aged , Pseudomonas/drug effects , Staphylococcus aureus/drug effects , Staphylococcus epidermidis/drug effects , Streptococcaceae/drug effects , Streptococcus/drug effects , Streptococcus mitis/drug effects , Streptococcus mutans/drug effects , Streptococcus oralis/drug effects , Streptococcus pyogenes/drug effects , Streptococcus sanguis/drug effects , Streptococcus sobrinus/drug effects , Time Factors , Viridans Streptococci/drug effects
8.
Fish Shellfish Immunol ; 25(1-2): 181-7, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18499476

ABSTRACT

Two antimicrobial peptides from haemocytes of the American lobster, Homarus americanus H. Milne Edwards 1837, were isolated and partially characterised - the first such description for this species. CAP-2, an approximately 12kDa peptide, contained amino acid sequences corresponding to the predicted sequence for Hoa-crustin. Crustins are whey acidic protein (WAP) domain - containing peptides isolated from crustacean haemocytes. CAP-2 did not have any activity towards the Gram positive coccus Aerococcus viridans unlike carcinin, a crustin from Carcinus maenas haemocytes, which may partially explain the lobster's susceptibility to this bacterium. A second peptide, CAP-1, was a multimer composed of 4-6kDa subunits with similarities to amphibian temporins. CAP-1 may represent a novel group of antimicrobial peptides for marine invertebrates and has been tentatively named 'homarin'. Homarin had bacteriostatic activity against some Gram negative bacteria and both protozoastatic and protozoacidal activity against two cultured scuticociliate parasites Mesanophrys chesapeakensis and Anophryoides haemophila, the latter a significant pathogen of H. americanus.


Subject(s)
Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/isolation & purification , Hemocytes/chemistry , Nephropidae/chemistry , Amino Acid Sequence , Animals , Antimicrobial Cationic Peptides/pharmacology , Ciliophora/drug effects , Microbial Sensitivity Tests , Molecular Sequence Data , Parasitic Sensitivity Tests , Sequence Alignment , Streptococcaceae/drug effects
9.
Clin Microbiol Infect ; 14(2): 124-9, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18076671

ABSTRACT

In-vitro MICs and minimum bactericidal concentrations (MBCs) of daptomycin, linezolid, tigecycline, vancomycin and teicoplanin against Gram-positive bacteria were determined using the broth microdilution method for ten blood isolates each of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), including two vancomycin-intermediate S. aureus (VISA), vancomycin-resistant Enterococcus faecium and Enterococcus faecalis. One strain of VISA was tested in a time-kill synergism assay of daptomycin combined with oxacillin, imipenem, rifampicin and isepamicin. Daptomycin showed excellent in-vitro bactericidal activity against all the isolates tested, with no tolerance or synergism effects when combined with other agents, except with rifampicin against VISA. Vancomycin had better bactericidal activity against MRSA and MSSA than did teicoplanin. Linezolid had the poorest bactericidal activity against the isolates tested, with 100% tolerance by the MSSA and VRE isolates, and 80% tolerance by the MRSA isolates. Tolerance towards tigecycline was exhibited by 40% of the MRSA isolates, 100% of the MSSA and vancomycin-resistant E. faecalis isolates, and 90% of the vancomycin-resistant E. faecium isolates.


Subject(s)
Anti-Infective Agents/pharmacology , Gram-Positive Bacterial Infections/microbiology , Gram-Positive Cocci/drug effects , Acetamides/pharmacology , Daptomycin/pharmacology , Drug Resistance, Bacterial , Drug Therapy, Combination , Glycopeptides/pharmacology , Gram-Positive Bacterial Infections/drug therapy , Humans , Linezolid , Microbial Sensitivity Tests/methods , Minocycline/analogs & derivatives , Minocycline/pharmacology , Oxazolidinones/pharmacology , Staphylococcus aureus/drug effects , Streptococcaceae/drug effects , Streptococcaceae/isolation & purification , Taiwan , Teicoplanin/pharmacology , Tigecycline , Time Factors , Vancomycin/pharmacology
10.
Lett Appl Microbiol ; 45(2): 190-3, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17651217

ABSTRACT

AIMS: To investigate the effects of two prebiotics and trehalose on the production of bacteriocins. METHODS AND RESULTS: Four carbohydrates [dextrose, fructo-oligosaccharides (FOS), raffinose, and trehalose] were used as the sole carbon source in a simple broth. Five bacteriocin-producing strains of bacteria, including those producing nisin, enteriocin, and other bacteriocins, were used, and their inhibitory activities when grown on each carbohydrate were determined. The inhibitory activity assay was performed using the agar well diffusion method, and Lactobacillus sakei JCM 1,157(T) was used as the indicator strain. Effective enhancement of bacteriocin production was observed with FOS and trehalose incubation. CONCLUSIONS: The results suggest that FOS and trehalose can effectively enhance the production of the five kinds of bacteriocins evaluated in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: This study offers useful information for not only a new application of FOS and trehalose, but also the potential improvement of food preservation.


Subject(s)
Bacteriocins/biosynthesis , Lactobacillus , Oligosaccharides/pharmacology , Streptococcaceae , Trehalose/pharmacology , Bacteriocins/pharmacology , Biotechnology/methods , Food Preservation/methods , Lactobacillus/drug effects , Lactobacillus/growth & development , Lactobacillus/metabolism , Microbial Sensitivity Tests , Oligosaccharides/metabolism , Streptococcaceae/drug effects , Streptococcaceae/growth & development , Streptococcaceae/metabolism , Trehalose/metabolism
11.
J Clin Microbiol ; 45(9): 3053-7, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17596355

ABSTRACT

We present here the biochemical and genetic characterization and antimicrobial susceptibility of 58 isolates of Aerococcus viridans isolated in pure culture from different clinical specimens of normally sterile body sites of pigs. A. viridans isolates were commonly susceptible to beta-lactam antimicrobials and exhibited a great genetic heterogeneity as determined by pulsed-field gel electrophoresis typing. The results indicate that A. viridans might be included in the list of possible etiological agents causing disease in pigs.


Subject(s)
Gram-Positive Bacterial Infections/veterinary , Streptococcaceae/drug effects , Streptococcaceae/genetics , Swine Diseases/microbiology , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Typing Techniques , Carbohydrate Metabolism , Cluster Analysis , DNA Fingerprinting , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Gram-Positive Bacterial Infections/microbiology , Microbial Sensitivity Tests , Polymorphism, Genetic , Streptococcaceae/isolation & purification , Streptococcaceae/physiology , Swine
13.
Appl Environ Microbiol ; 73(3): 730-9, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17122388

ABSTRACT

The antibiotic resistances of 45 lactic acid bacteria strains belonging to the genera Lactobacillus, Streptococcus, Lactococcus, Pediococcus, and Leuconostoc were investigated. The objective was to determine antibiotic resistances and to verify these at the genetic level, as is currently suggested by the European "qualified presumption of safety" safety evaluation system for industrial starter strains. In addition, we sought to pinpoint possible problems in resistance determinations. Primers were used to PCR amplify genes involved in beta-lactam antibiotic, chloramphenicol, tetracycline, and erythromycin resistance. The presence of ribosomal protection protein genes and the ermB gene was also determined by using a gene probe. Generally, the incidences of erythromycin, chloramphenicol, tetracycline, or beta-lactam resistances in this study were low (<7%). In contrast, aminoglycoside (gentamicin and streptomycin) and ciprofloxacin resistances were higher than 70%, indicating that these may constitute intrinsic resistances. The genetic basis for ciprofloxacin resistance could not be verified, since no mutations typical of quinolone resistances were detected in the quinolone determining regions of the parC and gyrA genes. Some starter strains showed low-level ampicillin, penicillin, chloramphenicol, and tetracycline resistances, but no known resistance genes could be detected. Although some strains possessed the cat gene, none of these were phenotypically resistant to chloramphenicol. Using reverse transcription-PCR, these cat genes were shown to be silent under both inducing and noninducing conditions. Only Lactobacillus salivarius BFE 7441 possessed an ermB gene, which was encoded on the chromosome and which could not be transferred in filter-mating experiments. This study clearly demonstrates problems encountered with resistance testing, in that the breakpoint values are often inadequately identified, resistance genes may be present but silent, and the genetic basis and associated resistance mechanisms toward some antibiotics are still unknown.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Drug Resistance, Bacterial , Lactobacillus/drug effects , Probiotics , Streptococcaceae/drug effects , Amino Acid Sequence , Animals , Cheese/microbiology , DNA Gyrase/chemistry , DNA Gyrase/genetics , DNA Topoisomerase IV/chemistry , DNA Topoisomerase IV/genetics , Drug Resistance, Bacterial/genetics , Lactobacillus/genetics , Meat Products/microbiology , Microbial Sensitivity Tests/methods , Microbial Sensitivity Tests/standards , Molecular Sequence Data , Sequence Analysis, DNA , Streptococcaceae/classification , Streptococcaceae/genetics , Yogurt/microbiology
14.
Dis Aquat Organ ; 69(2-3): 197-203, 2006 Apr 06.
Article in English | MEDLINE | ID: mdl-16724563

ABSTRACT

Phagocytic responses in circulating hemocytes of the lobster Homarus americanus were measured before and after treatment of lobsters with 2 different immunogens: (1) lipolysaccharide (LPS) or endotoxin from a non-pathogenic Pseudomonas perolens, and (2) a vancomycin/live Gram-positive pathogen (Aerococcus viridans [var.] homari) combination, essentially attenuated cells, shown previously to induce a high degree of resistance to this pathogen. The responses elicited by each of the immunogens were markedly different. Hemocytes drawn from LPS-treated lobsters showed significant, largely non-specific, increases in phagocytic responses over baseline values against sheep red blood cells and an array of test bacteria, with the notable exception of the pathogen. In marked contrast, induction with the vancomycin/live pathogen combination resulted in highly significant and specific increases in phagocytic responses to the pathogen and to the related, (but avirulent) strains of the pathogen, as well as inducing in the lobsters the usual high degree of resistance to the pathogen. These results suggest that quantitative and qualitative variations in phagocytic and resistance levels induced in at least 1 crustacean genus are determined largely by the particular characteristics of the immunogen.


Subject(s)
Hemocytes/immunology , Nephropidae/immunology , Phagocytosis/immunology , Animals , Anti-Bacterial Agents/pharmacology , Endotoxins/administration & dosage , Endotoxins/immunology , Endotoxins/pharmacology , Hemocytes/drug effects , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/immunology , Mucins/immunology , Nephropidae/drug effects , Phagocytosis/drug effects , Pseudomonas/immunology , Streptococcaceae/drug effects , Streptococcaceae/immunology , Vancomycin/pharmacology
15.
Drug Dev Ind Pharm ; 32(2): 229-38, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16537203

ABSTRACT

Gelatin microparticles containing propolis ethanolic extractive solution were prepared by spray-drying technique. Particles with regular morphology, mean diameter ranging of 2.27 microm to 2.48 microm, and good entrapment efficiency for propolis were obtained. The in vitro antimicrobial activity of microparticles was evaluated against microorganisms of oral importance (Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus, Candida albicans, and Lactobacillus casei). The utilized techniques were diffusion in agar and determination of minimum inhibitory concentration. The choice of the method to evaluate the antimicrobial activity of microparticles showed be very important. The microparticles displayed activity against all tested strains of similar way to the propolis, showing greater activity against the strains of E. salivarius, S. sanguinis, S. mitis, and C. albicans.


Subject(s)
Anti-Infective Agents/administration & dosage , Anti-Infective Agents/therapeutic use , Gelatin/chemistry , Propolis/administration & dosage , Propolis/therapeutic use , Candida albicans/drug effects , Drug Carriers , Ethanol/chemistry , Lacticaseibacillus casei/drug effects , Microbial Sensitivity Tests , Particle Size , Streptococcaceae/drug effects
16.
J Dairy Sci ; 88(10): 3710-20, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16162546

ABSTRACT

Environmental bacteria have emerged over the past few years to become significant causes of mastitis. Bacteria in this group are often reported by practicing veterinarians to be increasingly resistant to intramammary therapy and responsible for elevated bulk tank somatic cell counts. The purpose of this study was to determine the extent of association of the minimum inhibitory concentrations for selected antimicrobial agents with environmental bacteria isolated from bulk tank milk on California dairies and their housing facilities, husbandry practices, and antimicrobic-use strategies. Bulk tank milk samples were collected from 2 dairy cooperatives that had their milk cultured at the Milk Quality Laboratory, University of California Davis, Veterinary Medicine Teaching and Research Center in Tulare, CA. Samples were collected from July 2001 through March 2002 on 88 d; and 404 environmental bacteria isolated from 93 dairies were found. Minimum inhibitory concentrations were determined on 337 of the isolates for 10 antimicrobial agents. Cluster analysis was performed on the minimum inhibitory concentration values for each organism, and 4 antimicrobial clusters with varying degrees of resistance were found.A 69-question survey questionnaire was completed on-farm for 49 of the 73 dairies that had at least 3 environmental bacterial isolates. The questionnaire sought information on housing facilities, milking management, mastitis prevention, antimicrobial usage strategies, and owner/veterinary involvement in disease control and prevention. Multinomial logistic regression analysis found significant associations between the antimicrobial agent-resistance cluster groups and some of the housing and bedding practices, failure to dry udders before milking, and antimicrobial treatment of nonmastitis conditions. No association was noted for antimicrobial agent treatment of mastitis and the resistance cluster patterns.


Subject(s)
Anti-Infective Agents/administration & dosage , Cluster Analysis , Dairying/methods , Environment , Microbial Sensitivity Tests/veterinary , Milk/microbiology , Animals , Bacteria/drug effects , Bacteria/isolation & purification , Cattle , Enterococcus/drug effects , Enterococcus/isolation & purification , Female , Lactococcus/drug effects , Lactococcus/isolation & purification , Logistic Models , Mastitis, Bovine/prevention & control , Streptococcaceae/drug effects , Streptococcaceae/isolation & purification , Streptococcus/drug effects , Streptococcus/isolation & purification , Surveys and Questionnaires
17.
Lett Appl Microbiol ; 41(2): 119-24, 2005.
Article in English | MEDLINE | ID: mdl-16033507

ABSTRACT

AIMS: To determine the effect of diet acidification and an in-feed antibiotic growth promotant (Tylosin, Ty) on selected culturable bacterial populations in the gastrointestinal tract (GIT) of mice. METHODS AND RESULTS: Female C57Bl mice were given a standard diet supplemented with Acid Pak (AP) or Ty in the drinking water. After 21 days, lumen and adherent populations of Enterobacteriaceae, enterococci/streptococci, and lactic acid bacteria (LAB) from the ileum, caecum, colon and faeces were enumerated. General intestinal health was assessed by the frequency of haemolytic bacteria in the different intestinal compartments. Contrary to expectations, AP and Ty significantly increased haemolytic bacteria in the lumen of the caecum and colon (P<0.05). The small but significant growth-enhancing effect of Ty (P<0.05) was associated with decreases in enterococci/streptococci and surprisingly, LAB, as well as increases in coliforms. AP, which failed to improve growth rates, reduced coliforms, had limited effects on enterococci/streptococci, and specifically failed to promote the growth of LAB populations in all intestinal compartments. Ty supplementation was also associated with a significant increase in macrolide-resistant enterococci throughout the GIT. CONCLUSIONS: Dietary acidification is less effective than Ty in modulating the population dynamics of selected culturable populations of enteric bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The mouse can provide a useful experimental model to examine the effects of new dietary supplements, formulations or regimes on changes in microbial population dynamics, including monitoring for antibiotic resistance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Gastrointestinal Tract/microbiology , Probiotics/pharmacology , Tylosin/pharmacology , Animals , Anti-Bacterial Agents/administration & dosage , Colony Count, Microbial , Diet , Dietary Supplements , Drug Resistance, Bacterial , Enterobacteriaceae/drug effects , Enterobacteriaceae/isolation & purification , Feces/microbiology , Female , Hydrogen-Ion Concentration , Mice , Mice, Inbred C57BL , Probiotics/administration & dosage , Streptococcaceae/drug effects , Streptococcaceae/isolation & purification , Tylosin/administration & dosage
19.
Can J Microbiol ; 51(1): 51-8, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15782234

ABSTRACT

In the production of the Spanish traditional blue-veined Cabrales cheese, lactic acid bacteria strains free of antibiotic resistance that have a transferrable capacity are necessary as components of a specific starter. To select for these bacteria, the minimum inhibitory concentration (MIC) of 12 antibiotics and 2 mixtures (containing beta-lactamase inhibitor and penicillin) were determined by microbroth and agar dilution techniques in 146 strains belonging to the genera Lactococcus, Enterococcus, Lactobacillus, and Leuconostoc. The antibiotic-resistance profiles of Lactococcus and Enterococcus species were different from those of Lactobacillus and Leuconostoc, but clear genus- or species-associated patterns were not observed. Cefoxitin and metronidazole were not effective against bacteria of these genera. The MICs of beta-lactam antibiotics for lactobacilli and leuconostoc isolates were higher than those for lactococci and enterococci, but no strain was clinically resistant. All lactobacilli and leuconostoc isolates were resistant to high levels of vancomycin, a type of resistance not seen among the tested members of the genera Lactococcus and Enterococcus. The majority of the observed resistance appeared to be either intrinsic or nonspecific, although some strains of Lactococcus lactis, Enterococcus spp., and Lactobacillus spp. were resistant to antibiotics, such as chloramphenicol, erythromycin, clindamycin, or tetracycline.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cheese/microbiology , Lactobacillus/drug effects , Streptococcaceae/drug effects , Drug Resistance, Bacterial , Lactic Acid/metabolism , Lactobacillus/isolation & purification , Microbial Sensitivity Tests , Streptococcaceae/isolation & purification
20.
J Clin Microbiol ; 42(9): 4323-6, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15365035

ABSTRACT

Abiotrophia and Granulicatella species have been associated with various infections. Antimicrobial susceptibility data for these nutritionally variant streptococcus-like organisms, especially for pediatric isolates, are very limited. Little is known about the genetic bases of their resistance mechanisms. We report the results of identification to bacterial species level, antimicrobial susceptibility testing, macrolide resistance testing, and detection of genes encoding that resistance for a collection of 15 pediatric clinical isolates from normally sterile sites. Our results indicate that the prevalence of beta-lactam and macrolide resistance is high and that both erm and mef are found in these isolates.


Subject(s)
Lactobacillaceae/isolation & purification , Streptococcaceae/isolation & purification , Base Sequence , Child , Child, Preschool , Clindamycin/pharmacology , DNA Primers , Erythromycin/pharmacology , Female , Gram-Positive Bacterial Infections , Humans , Infant , Lactobacillaceae/drug effects , Macrolides/pharmacology , Male , Microbial Sensitivity Tests , Streptococcaceae/drug effects
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