Assessment of Efficacy of BLIS-Producing Probiotic K12 for the Prevention of Group A Streptococcus Pharyngitis: a Short Communication.

The neutral outcome of the recently reported school-based trial of probiotic K12 (The effect of the oral probiotic Streptococcus salivarius K12 on group A streptococcus pharyngitis: a pragmatic trial in schools) can be attributed at least partially to several readily identifiable confounding factors. Mainly, the execution and outcome were negatively impacted by (a) the suboptimal efficacy and frequency of K12 administration, (b) the failure both clinically and microbiologically to adequately diagnose and distinguish active group A streptococci (GAS) pharyngitis from harmless GAS carriage, and (c) the exceptionally low occurrence of GAS in this population at the time of the probiotic intervention due to recent high-intensity antibiotic exposure.

Assessment of acoustic pulse therapy (APT), a non-antibiotic treatment for dairy cows with clinical and subclinical mastitis.

Clinical and subclinical mastitis affects 30% of cows and is regarded as the most significant economic burden on the dairy farm reducing milk yield and quality and increasing culling rate. A proprietary Acoustic Pulse Therapy (APT) device was developed specifically for treating dairy cows. The APT device was designed to produce deep penetrating acoustic pulses that are distributed over a large treated area at a therapeutic level. This paper presents findings from a clinical assessment of this technology for the treatment of dairy cows with subclinical and clinical mastitis. In subclinical mastitis, a group of 116 cows from 3 herds were identified with subclinical intramammary infection and enrolled in the study; 78 cows were assigned to the treatment group and 38 cows to the control group. Significant differences (P<0.001) were found where 70.5% of the cows in the treatment group returned to normal milk production, compared with only 18.4% of the control group. Daily milk yields of the treated cows increased significantly (P<0.05) and the percentage of cows with log somatic cell count under 5.6 cells/mL was significantly higher (P<0.001). Milk of the infected quarters appeared normal with lactose greater than 4.8%, but this difference was not significant. Of the treated cows with identified bacteria, 52.6% of the quarters were cured, while in the control group only 25.0% (P<0.001). Specifically, all cows identified with Escherichia coli in the treatment group were cured, with 66.6% cured with no intervention in the control. Spontaneous cure of glands infected with coagulase negative staphylococci (CNS) and Streptococci was low while treatment successfully increased the cure of CNS from 13.3% to 53.8% and that of Streptococci from 18.2% to 36.4%. Of the 4 cows identified with Staphylococcus aureus, 3 were cured. The clinical mastitis study group included 29 infected cows that were submitted either to a gold standard antibiotic treatment subgroup of 16 cows (n = 16) or to an APT treatment subgroup of 13 cows (n = 13). A cure of 18.7% was shown for the antibiotic treatment, of which logSCC returned to <5.6 cell/mL and 56.2% were culled. A cure of 76.9% was shown for the APT treatment with only one cow culled (7.7%).

Pharmacokinetics of Penicillin G in Preterm and Term Neonates.

Group B streptococci are common causative agents of early-onset neonatal sepsis (EOS). Pharmacokinetic (PK) data for penicillin G have been described for extremely preterm neonates but have been poorly described for late-preterm and term neonates. Thus, evidence-based dosing recommendations are lacking. We describe the PK of penicillin G in neonates with a gestational age (GA) of ≥32 weeks and a postnatal age of <72 h. Penicillin G was administered intravenously at a dose of 25,000 or 50,000 IU/kg of body weight every 12 h (q12h). At steady state, PK blood samples were collected prior to and at 5 min, 1 h, 3 h, 8 h, and 12 h after injection. Noncompartmental PK analysis was performed with WinNonlin software. With those data in combination with data from neonates with a GA of ≤28 weeks, we developed a population PK model using NONMEM software and performed probability of target attainment (PTA) simulations. In total, 16 neonates with a GA of ≥32 weeks were included in noncompartmental analysis. The median volume of distribution (V) was 0.50 liters/kg (interquartile range, 0.42 to 0.57 liters/kg), the median clearance (CL) was 0.21 liters/h (interquartile range, 0.16 to 0.29 liters/kg), and the median half-life was 3.6 h (interquartile range, 3.2 to 4.3 h). In the population PK analysis that included 35 neonates, a two-compartment model best described the data. The final parameter estimates were 10.3 liters/70 kg and 29.8 liters/70 kg for V of the central and peripheral compartments, respectively, and 13.2 liters/h/70 kg for CL. Considering the fraction of unbound penicillin G to be 40%, the PTA of an unbound drug concentration that exceeds the MIC for 40% of the dosing interval was >90% for MICs of ≤2 mg/liter with doses of 25,000 IU/kg q12h. In neonates, regardless of GA, the PK parameters of penicillin G were similar. The dose of 25,000 IU/kg q12h is suggested for treatment of group B streptococcal EOS diagnosed within the first 72 h of life. (This study was registered with the EU Clinical Trials Register under EudraCT number 2012-002836-97.).

Metabolic-Activity-Based Assessment of Antimicrobial Effects by D2O-Labeled Single-Cell Raman Microspectroscopy.

To combat the spread of antibiotic resistance, methods that quantitatively assess the metabolism-inhibiting effects of drugs in a rapid and culture-independent manner are urgently needed. Here using four oral bacteria as models, we show that heavy water (D2O)-based single-cell Raman microspectroscopy (D2O-Raman) can probe bacterial response to different drugs using the Raman shift at the C-D (carbon-deuterium vibration) band in 2040 to 2300 cm-1 as a universal biomarker for metabolic activity at single-bacterial-cell resolution. The "minimum inhibitory concentration based on metabolic activity" (MIC-MA), defined as the minimal dose under which the median ΔC-D-ratio at 8 h of drug exposure is ≤0 and the standard deviation (SD) of the ΔC-D ratio among individual cells is ≤0.005, was proposed to evaluate the metabolism-inhibiting efficacy of drugs. In addition, heterogeneity index of MIC-MA (MIC-MA-HI), defined as SD of C-D ratio among individual cells, quantitatively assesses the among-cell heterogeneity of metabolic activity after drug regimens. When exposed to 1× MIC of sodium fluoride (NaF), 1× MIC of chlorhexidine (CHX), or 60× MIC of ampicillin, the cariogenic oral pathogen Streptococcus mutans UA159 ceased propagation yet remained metabolically highly active. This underscores the advantage of MIC-MA over the growth-based MIC in being able to detect the "nongrowing but metabolically active" (NGMA) cells that underlie many latent or recurring infections. Moreover, antibiotic susceptible and resistant S. mutans strains can be readily discriminated at as early as 0.5 h. Thus, D2O-Raman can serve as a universal method for rapid and quantitative assessment of antimicrobial effects based on general metabolic activity at single-cell resolution.

Short communication: an in vitro assessment of the antibacterial activity of plant-derived oils.

Nonantibiotic treatments for mastitis are needed in organic dairy herds. Plant-derived oils may be useful but efficacy and potential mechanisms of action of such oils in mastitis therapy have not been well documented. The objective of the current study was to evaluate the antibacterial activity of the plant-derived oil components of Phyto-Mast (Bovinity Health LLC, Narvon, PA), an herbal intramammary product, against 3 mastitis-causing pathogens: Staphylococcus aureus, Staphylococcus chromogenes, and Streptococcus uberis. Plant-derived oils evaluated were Thymus vulgaris (thyme), Gaultheria procumbens (wintergreen), Glycyrrhiza uralensis (Chinese licorice), Angelica sinensis, and Angelica dahurica. Broth dilution testing according to standard protocol was performed using ultrapasteurized whole milk instead of broth. Controls included milk only (negative control), milk + bacteria (positive control), and milk + bacteria + penicillin-streptomycin (antibiotic control, at 1 and 5% concentrations). Essential oil of thyme was tested by itself and not in combination with other oils because of its known antibacterial activity. The other plant-derived oils were tested alone and in combination for a total of 15 treatments, each replicated 3 times and tested at 0.5, 1, 2, and 4% to simulate concentrations potentially achievable in the milk within the pre-dry-off udder quarter. Thyme oil at concentrations ≥2% completely inhibited bacterial growth in all replications. Other plant-derived oils tested alone or in various combinations were not consistently antibacterial and did not show typical dose-response effects. Only thyme essential oil had consistent antibacterial activity against the 3 mastitis-causing organisms tested in vitro. Further evaluation of physiological effects of thyme oil in various preparations on mammary tissue is recommended to determine potential suitability for mastitis therapy.

Species-level assessment of the molecular basis of fluoroquinolone resistance among viridans group streptococci causing bacteraemia in cancer patients.

Viridans group streptococci (VGS) are a major cause of bacteraemia in neutropenic cancer patients, particularly those receiving fluoroquinolone prophylaxis. In this study, we sought to understand the molecular basis for fluoroquinolone resistance in VGS causing bacteraemia in cancer patients by assigning 115 VGS bloodstream isolates to specific species using multilocus sequence analysis (MLSA), by sequencing the quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE, and by testing strain susceptibility to various fluoroquinolones. Non-susceptibility to one or more fluoroquinolones was observed for 78% of isolates, however only 68.7% of patients were receiving fluoroquinolone prophylaxis. All but one of the determinative QRDR polymorphisms occurred in GyrA or ParC, yet the pattern of determinative QRDR polymorphisms was significantly associated with the fluoroquinolone prophylaxis received. By combining MLSA and QRDR data, multiple patients infected with genetically indistinguishable fluoroquinolone-resistant Streptococcus mitis or Streptococcus oralis strains were discovered. Together these data delineate the molecular mechanisms of fluoroquinolone resistance in VGS isolates causing bacteraemia and suggest possible transmission of fluoroquinolone-resistant S. mitis and S. oralis isolates among cancer patients.

Assessment of the susceptibility of lactic acid bacteria to biocides.

Biocides are antimicrobial compounds that are widely used in the food industry and medical environments. In this study, we determined the Minimum Inhibitory Concentrations (MICs) by the microdilution method of four different biocides for a large collection of LAB of different origins. The tested isolates belong to 11 species of the Lactobacillus genus and to Streptococcus thermophilus, Streptococcus salivarius and Lactococcus garvieae. The results obtained in this study indicate that low susceptibilities to benzalkonium chloride (BC), triclosan (Tr), chlorhexidine (Ch), and sodium hypochlorite (SH) are not frequent among LAB. Moreover, no systematic co-tolerance between two or more tested biocides was found; that is, strains displaying high MIC values and thus low sensitivity to one of the biocides did not show higher MIC values for the other biocides.

Semiparametric bayesian testing procedure for noninferiority trials with binary endpoints.

A semiparametric testing approach based on the Bayes factor is developed for non-inferiority trials with binary endpoints. The proposed method is shown to work for a broad class of hypotheses by accommodating a variety of dissimilarity measures between two binomial parameters. Two of the unique features of the proposed testing procedure include: (i) construction of a flexible class of conjugate priors using a mixture of beta densities to maintain approximate equality of prior probabilities of the competing hypotheses; and (ii) automatic determination of the cutoff value of the Bayes factor to facilitate the decision making process. In contrast to the use of Jeffreys's rule of thumb, two forms of total weighted average error criteria are used to determine the cutoff value. Through several simulation studies it is demonstrated that the proposed Bayesian procedure has competitive frequentist properties of controlling type I error as compared to the default frequentist test and meanwhile the proposed criterion improves the statistical power, especially in small samples. The method is further illustrated using the data from a streptococcal pharyngitis clinical trial.

Optimal dosage regimen of meropenem for pediatric patients based on pharmacokinetic/pharmacodynamic considerations.

A population pharmacokinetic (PK) model for meropenem in Japanese pediatric patients with various infectious diseases was developed based on 116 plasma concentrations from 50 pediatric patients. The population PK parameters developed in this analysis are useful for calculation of the percent time above minimum inhibitory concentration (%T>MIC) and for optimal dosing of meropenem in pediatric patients. After dosing at 20 mg/kg t.i.d. by 0.5-h infusion (approved standard dose for pediatric patients in Japan), the target value of 50%T>MIC was achieved, indicating that 20 mg/kg t.i.d. by 0.5-h infusion is effective for susceptible bacteria. In contrast, for bacteria with higher MICs such as Pseudomonas aeruginosa (MIC ≥ 2 µg/mL), the probability of target attainment of 50%T>MIC was 60.7% at a dose of 40 mg/kg t.i.d. by 0.5-h infusion (highest dose approved for pediatric patients in Japan). The simulations described in this article indicated that 40 mg/kg t.i.d. with a longer infusion duration (e.g., 4 h) is more effective against bacteria with a MIC higher than 2 µg/mL. The predicted probability of target attainment for 50%T>MIC (97.0%) was well correlated not only to the microbiological efficacy rate (97.0%) but also to the clinical efficacy rate (95.9%) in the present phase 3 study.

Microbial culture and checkerboard DNA-DNA hybridization assessment of bacteria in root canals of primary teeth pre- and post-endodontic therapy with a calcium hydroxide/chlorhexidine paste.

AIM: To investigate the root canal microbiota of primary teeth with apical periodontitis and the in vivo antimicrobial effects of a calcium hydroxide/chlorhexidine paste used as root canal dressing. DESIGN: Baseline samples were collected from 30 root canals of primary teeth with apical periodontitis. Then, the root canals were filled with a calcium hydroxide paste containing 1% chlorhexidine for 14 days and the second bacteriologic samples were taken prior to root canal filling. Samples were submitted to microbiologic culture procedure to detect root canal bacteria and processed for checkerboard DNA-DNA hybridization. RESULTS: Baseline microbial culture revealed high prevalence and cfu number of anaerobic, black-pigmented bacteroides, Streptococcus, and aerobic microorganisms. Following root canal dressing, the overall number of cfu was dramatically diminished compared to initial contamination (P <0.05), although prevalence did not change (P > 0.05). Of 35 probes used for checkerboard DNA-DNA hybridization, 31 (88.57%) were present at baseline, and following root canal dressing, the number of positive probes reduced to 13 (37.14%). Similarly, the number of bacterial cells diminished folowing application of calcium hydroxide/chlorhexidine root canal dressing (P = 0.006). CONCLUSION: Apical periodontitis is caused by a polymicrobial infection, and a calcium hydroxide/chlorhexidine paste is effective in reducing the number of bacteria inside root canals when applied as a root canal dressing.

Antimicrobial properties of stem bark extracts from Phyllanthus muellerianus (Kuntze) Excell.

ETHNOPHARMACOLOGICAL RELEVANCE: The plants of the genus Phyllanthus (Euphorbiaceae) are widely distributed in most tropical and subtropical countries, and have long been used in folk medicine to treat several diseases. Particularly, Phyllanthus muellerianus (Kuntze) Excell, commonly called "mbolongo" in Cameroon, is used by pygmies baka as a remedy for tetanus and wound infections. AIM OF THE STUDY: To investigate the antimicrobial properties of Phyllanthus muellerianus (Kuntze) Excell (family Euphorbiaceae) stem bark used in Cameroon by baka pygmies as a remedy for wound healing and tetanus. MATERIALS AND METHODS: Aqueous and methanol extracts with and without defatting treatment, were prepared and their activity against Clostridium sporogenes ATCC 3584, Staphylococcus aureus ATCC 6538, Streptococcus mutans ATCC 25175, Streptococcus pyogenes ATCC 19615, Escherichia coli ATCC 10536, Candida albicans ATCC 10231, was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal-fungicidal concentration (MBC-MFC) by the macrodilution method. RESULTS: Water extract showed a weak activity against Clostridium sporogenes (MIC 900 µg/mL) and resulted inactive at the tested concentrations against all the other microorganisms. The defatted methanol extract, inactive against Staphylococcus aureus, Escherichia coli, Candida albicans, exhibited a very interesting activity against Clostridium sporogenes and Streptococcus pyogenes (MIC 100 µg/mL and 300 µg/mL, respectively), which seems to validate the use of this plant in pygmies traditional medicine for the treatment of tetanus and wound infections. The activity found against Streptococcus mutans (300 µg/mL), aetiological agent of caries, may suggest a possible use of this plant as natural remedy to prevent dental diseases. CONCLUSIONS: The activity against streptococci and Clostridium sporogenes ATCC 3584, showed by stem bark extracts of Phyllanthus muellerianus, traditionally used by baka pygmies to treat wound infections and tetanus, is reported for the first time.

Ceftriaxone plus gentamicin or ceftriaxone alone for streptococcal endocarditis in Japanese patients as alternative first-line therapies.

This study included 31 patients who had definite or possible infectious endocarditis as defined by the modified Duke's criteria Of these patients, 27 were treated with ceftriaxone plus gentamycin combination therapy and four with ceftriaxone monotherapy. Of these 31 cases, 29 had infections with Streptococcus species, and showed good responses to penicillin G and cefotaxime. Excluding one patient who died because of the underlying disease, all patients achieved clinical cure after treatment with either of the two regimens, showing no recurrence during a follow-up period of 6 months after completion of drug treatment. Although valve replacement was performed in 10 patients during the follow-up period, there were no recurrences in any of these patients 6 months postoperatively. Ceftriaxone allows a simple regimen of once-daily administration. Although indications are limited, ceftriaxone therapy is feasible on an outpatient basis, offering favorable medical economics. Consistent with previous reports, the therapeutic effect of ceftriaxone was equivalent to that of penicillin G in this study, showing this agent to be an alternative first-line drug for infectious endocarditis.

Assessment of the in vitro efficacy of the novel antimicrobial peptide CECT7121 against human Gram-positive bacteria from serious infections refractory to treatment.

BACKGROUND: Resistant Gram-positive bacteria are causing increasing concern in clinical practice. This work investigated the efficacy of AP-CECT7121 (an antimicrobial peptide isolated from an environmental strain of Enterococcus faecalis CECT7121) against various pathogenic Gram-positive bacteria. METHODS: Strains were isolated from intensive care unit patients unresponsive to standard antibiotic treatments. Inhibitory activity of AP-CECT7121 was assessed using the agar-well diffusion method. The most resistant isolates from each species screened (Enterococcus faecium, Enterococcus faecalis,Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Clostridium perfringens and Clostridium difficile) were further examined in time-killing curve studies. RESULTS: These bactericidal kinetic experiments demonstrated a rapid killing effect with no viable bacteria being detected within 30 and 90 min for enterococcal and streptococcal strains and 180 min for community-acquired methicillin-resistant S. aureus and C. perfringens: viable counts for C. difficile were threefold decreased after 90 min. CONCLUSIONS: AP-CECT7121 may provide a novel strategy for treating potentially fatal clinical infections in hospitalized patients.

Application of patient population-derived pharmacokinetic-pharmacodynamic relationships to tigecycline breakpoint determination for staphylococci and streptococci.

Correctly determined susceptibility breakpoints are important to both the individual patient and to society at large. A previously derived patient population pharmacokinetic model and Monte Carlo simulation (9999 patients) were used to create a likelihood distribution of tigecycline exposure, as measured by the area under the concentration-time curve at 24 h (AUC(24)). Each resultant AUC(24) value was paired with a clinically relevant fixed MIC value ranging from 0.12 to 2 mg/L. For each AUC(24)-MIC pair, the probability of microbiologic response was calculated using an exposure-response relationship, which was derived from patients with complicated skin and skin structure infections that involved Staphylococcus aureus or streptococci or both. The median probability of microbiologic success was 94% or greater for MIC values up to and including 0.25 mg/L. The median probability of microbiologic success was 66% or less for MIC values of 0.5 mg/L or greater. These data support a susceptibility breakpoint of 0.25 mg/L for S. aureus and streptococci.

Pharmacokinetic-pharmacodynamic modeling of dalbavancin, a novel glycopeptide antibiotic.

Dalbavancin is a novel glycopeptide with a 2-dose, once-weekly dosing regimen that is being developed for the treatment of complicated skin and skin structure infections caused by gram-positive bacteria. Monte Carlo simulations were performed for dalbavancin using population pharmacokinetic data and minimum inhibitory concentrations (MICs) for clinical trial isolates. The time-dependent target was the maintenance of free drug concentrations above the MIC for 14 days (t>MIC). The concentration-dependent target was an area under the concentration-time curve (AUC)/MIC ratio of approximately 1000 for Staphylococcus aureus and 100 for Streptococcus sp. These targets were used to estimate susceptibility breakpoints for dalbavancin. For S aureus, the estimated susceptibility breakpoint was MIC. For Streptococcus sp, the estimated susceptibility breakpoint was at least 2 mug/mL. Because dalbavancin MIC(90)s for these species are well below these values, the analysis supports the use of once-weekly dosing regimens of dalbavancin in the treatment of complicated skin and skin structure infections.

Safety assessment of the oral cavity probiotic Streptococcus salivarius K12.

Streptococcus salivarius is a prominent member of the oral microbiota and has excellent potential for use as a probiotic targeting the oral cavity. In this report we document safety data relating to S. salivarius K12, including assessment of its antibiogram, metabolic profiles, and virulence determinants, and we examine the microbial composition of saliva following the dosing of subjects with K12.

Assessment of accuracy of disk diffusion tests for the determination of antimicrobial susceptibility of common bovine mastitis pathogens: a novel approach.

A novel approach was used to assess disk diffusion accuracy for determination of antibiotic susceptibility of various bovine mastitis pathogens (Escherichia coli, Staphylococcus aureus, Staphylococcus chromogenes, and Streptococcus dysgalactiae). MIC and disk diffusion diameters were compared for 587 bovine mastitis bacterial isolates collected in Israel and 3,186 drug-organism combinations. Results were analyzed by ROC curves, Bayesian statistics, and standard descriptive methods. Low correlation was observed between results of disk diffusion and MIC for S. dysgalactiae and all antimicrobial agents, S. aureus and erythromycin and neomycin, and E. coli and gentamicin, neomycin, and polymyxin B. On a few occasions in which correlation was satisfactory, accepted susceptibility breakpoints to some of the antimicrobial agents resulted in high discrepancies with MIC results and new breakpoints were suggested-e.g., 21 mm for S. aureus susceptibility to penicillin G instead of 29 mm recommended by the National Committee for Clinical Laboratory Standards (NCCLS) and <21 mm, resistant, 21-25 mm, intermediate, and >25 mm, susceptible for susceptibility of E. coli to trimethoprim/sulfamethoxazole. Thus, this approach enabled determination of the most accurate breakpoints that best fitted the specific prevalence of susceptibility in Israel. Thus, we suggest its adoption by microbiology diagnostic laboratories for the provision of accurate antimicrobial susceptibility results when using the disk diffusion test.

Assessment of enzymatic cleaning agents and disinfectants against bacterial biofilms.

PURPOSE: Microbial biofilm has become difficult to control by antibiotic and biocide regimes that are effective against suspended bacteria. Their colonization of surfaces can be a problem and is generally controlled through cleaning and disinfection. This study was undertaken to examine the efficacy of the disinfectants including Bio-Ow, Econase CE, Gamanase GC 140, IndiAge 44L, Mannanase AMB, Multifect P-3000, Neutrase, Pandion, Paradigm, Pectinex Ultra SP-L, Promozyme, Resinase A2X, Spezyme AA300, Spezyme GA300 and Vinozym EC, and the proteinase against bacterial biofilms. METHODS: The effectiveness of 20 commercial disinfectants against Pseudomonas aeruginosa (P. aeruginosa) biofilms using a fluorometric technique was examined. Additionally the disinfectants were also tested against Lactobacillus bulgaricus (L. bulgaricus), Lactobacillus lactis (L. lactis) and Streptococcus thermophilus (S. thermophilus) isolates using microtitration tray based turbidimetric techniques. Escherichia coli (E. coli) was used as the test bacteria in the fluorometric control method. RESULTS: Among the first group of the enzymatic cleaning agents tested, four disinfectants (Pandion, Resinase A2X, Spezyme GA300 and Paradigm) were the most potent against bacterial biofilms after 30 min incubation time (residual bacterial count less than 10(3) CFU (colony forming units)/ml). However, only Resinase A2X and Paradigm showed a good effect on bacterial biofilms after 15 min incubation time. Proteinase disinfectants (alkalase, chymotrypsin, cryotin and krilltrypsin) from the second group of the disinfectants showed a good effect against P. aeruginosa biofilm when tested in the absence of milk. The performance of the disinfectants was reduced in the presence of milk. The minimum inhibitory concentration (MIC) of the cleaning agents was determined as the lowest concentration inhibiting bacterial growth. The MIC was tested on Lactobacillus bulgaricus (L. bulgaricus), Lactobacillus lactis (L. lactis) and Streptococcus thermophilus (S. thermophilus) isolates. The minimum inhibitory concentrations (MIC) for Paradigm against S. thermophilus and L. Lactis were lower than L. Bulgaricus. Whereas, the MIC of Pandion against L. bulgaricus was lower than MIC against L. lactis. Resinase A2X had no inhibitory effect on bacterial growth when the concentration was less than or equal to 2.4 mg/ml and Spezyme GA 300 concentration less than or equal to 7.3 mg/ml. Minimum inhibitory concentration of Pandion against L. bulgaricus was 2.7 microg/ml and against L. lactis 5.3 microg/ml. Growth of S. thermophilus was inhibited in all concentration of Pandion tested. CONCLUSIONS: The choice of disinfectant or cleaning agent along with the optimum concentration and the time of action is very important when destroying microbes. It is also important that the resistances of microbes to different disinfectants and cleaning agents be taken into account when planning the cleaning process

Effect of cavitation on chemical disinfection efficiency.

This study brings out the potential efficacy of hybrid techniques for water disinfection. The techniques studied include hydrodynamic cavitation, acoustic cavitation and treatment with chemicals like hydrogen peroxide and ozone. The hybrid techniques which combine hydrodynamic cavitation, acoustic cavitation and hydrogen peroxide appear to be an attractive alternative to any one technique on its own for the reduction in the heterotropic plate count bacteria as well as indicator microorganisms like the total coliforms, fecal coliforms and fecal streptococci.

Multicentre assessment of linezolid antimicrobial activity and spectrum in Europe: report from the Zyvox antimicrobial potency study (ZAPS-Europe).

OBJECTIVE: To evaluate the in vitro spectrum and activity of linezolid, a recent oxazolidinone, according to well-controlled surveillance data from 42 medical centers in 13 countries throughout Europe. METHODS: Participants tested the susceptibility of 125 clinical strains of enterococcal and staphylococcal species against 13 drugs using reference broth microdilution trays or the standardized disk diffusion method of the National Committee for Clinical Laboratory Standards (NCCLS). Streptococcal species (n = 25 at each center) were tested against six drugs using E test (AB BIODISK, Solna, Sweden). Quality assurance testing was conducted using NCCLS-recommended strains and verification of resistance to linezolid and other selected agents was performed by retesting strains at the regional (Europe) and international (USA) monitor sites. RESULTS: A total of 5598 strains from throughout Europe (91% compliance) were tested. Vancomycin resistance was reported in only 0.6 and 3.0% of Enterococcus faecalis and E. faecium, respectively. Penicillin resistance occurred in 25.1% of Streptococcus pneumoniae; 4.9% at the high-level (> or =2 mg/L). The MIC90 for linezolid was 1 mg/L for streptococci and 2 mg/L for enterococci and staphylococci. Using the US FDA- and EUCAST-recommended susceptible breakpoints for linezolid, there were no confirmed reports of linezolid resistance [minimum inhibitory concentration (MIC), > or =8 mg/L]. The distribution of linezolid MIC values was unimodal and varied between 0.25 and 1 mg/L for streptococci (>90% of isolates), and between 1 and 2 mg/L for staphylococci (>90%) and enterococci (>95%). There were no differences in linezolid susceptibility in the vancomycin-, oxacillin-, or penicillin-resistant subsets of strains when compared to susceptible organism populations. CONCLUSIONS: Compared to the North American component of this study, there was substantially less vancomycin resistance among E. faecium isolates (Europe 3.0% vs. North America 63.4%). While the occurrence of penicillin-resistant S. pneumoniae in Europe and North America was similar (25.1% vs. 29.7%), the recovery of high-level penicillin-resistant strains was nearly three-fold higher in North America (4.9% vs. 13.2%). Only linezolid was universally active against all the tested Gram-positive isolates at