Exploring the signature gut and oral microbiome in individuals of specific Ayurveda prakriti.

Diagnosis and treatment of various diseases in Ayurveda, the Indian system of medicine, relies on 'prakriti' phenotyping of individuals into predominantly three constitutions, kapha, pitta and vata. Recent studies propose that microbiome play an integral role in precision medicine. A study of the relationship between prakriti - the basis of personalized medicine in Ayurveda and that of gut microbiome, and possible biomarker of an individual's health, would vastly improve precision therapy. Towards this, we analyzed bacterial metagenomes from buccal (oral microbiome) and fecal (gut microbiome) samples of 272 healthy individuals of various predominant prakritis. Major bacterial genera from gut microbiome included Prevotella, Bacteroides and Dialister while oral microbiome included Streptococcus, Neisseria, Veilonella, Haemophilus, Porphyromonas and Prevotella. Though the core microbiome was shared across all individuals, we found prakriti specific signatures such as preferential presence of Paraprevotella and Christensenellaceae in vata individuals. A comparison of core gut microbiome of each prakriti with a database of 'healthy' microbes identified microbes unique to each prakriti with functional roles similar to the physiological characteristics of various prakritis as described in Ayurveda. Our findings provide evidence to Ayurvedic interventions based on prakriti phenotyping and possible microbial biomarkers that can stratify the heterogenous population and aid in precision therapy.

Evaluating the technological properties of lactic acid bacteria in Wagyu cattle milk.

This paper reveals the technological properties of lactic acid bacteria isolated from raw milk (colostrum and mature milk) of Wagyu cattle raised in Okayama Prefecture, Japan. Isolates were identified based on their physiological and biochemical characteristics as well as 16S rDNA sequence analysis. Streptococcus lutetiensis and Lactobacillus plantarum showed high acid and diacetyl-acetoin production in milk after 24 h of incubation at 40 and 30°C, respectively. These strains are thought to have potential for use as starter cultures and adjunct cultures for fermented dairy products.

Group A streptococcal bacteremias in Southwest Finland 2007-2018: epidemiology and role of infectious diseases consultation in antibiotic treatment selection.

The incidence of invasive group A streptococcal (GAS) infections has shown a fluctuating but increasing trend in Finland. The impact of infectious diseases specialist consultation (IDSC) on the antimicrobial therapy of GAS bacteremia has not been studied earlier. A retrospective study on adult GAS bacteremia in The Hospital District of Southwest Finland (HDSWF) was conducted from 2007 to 2018. Data on incidence of bacteremic GAS cases were gathered from the National Infectious Disease Register. Clinical data were obtained by reviewing the electronic patient records. The overall incidence of GAS bacteremia in HDSWF was 3.52/100,000, but year-to-year variation was observed with the highest incidence of 7.93/100,000 in 2018. A total of 212 adult GAS bacteremia cases were included. A record of IDSC was found (+) in 117 (55.2%) cases, not found (-) in 71 (33.5%) cases and data were not available in 24 (11.3%) cases. Among IDSC+ cases, 57.3% were on penicillin G treatment whereas in the group IDSC- only 22.5%, respectively (OR = 4.61, 95% CI 2.37-8.97; p < 0.001). The use of clindamycin as adjunctive antibiotic was more common among IDSC+ (54.7%) than IDSC- (21.7%) (OR = 4.51, 95% CI 2.29-8.87; p < 0.001). There was an increasing trend in incidence of GAS bacteremia during the study period. Narrow-spectrum beta-lactam antibiotics were chosen, and adjunctive clindamycin was more commonly used, if IDSC took place. This highlights the importance of availability of IDSC but calls for improved practice among infectious diseases specialists by avoiding combination therapy with clindamycin in non-severe invasive GAS infections.

The upper-airway microbiota and loss of asthma control among asthmatic children.

The airway microbiome has an important role in asthma pathophysiology. However, little is known on the relationships between the airway microbiome of asthmatic children, loss of asthma control, and severe exacerbations. Here we report that the microbiota's dynamic patterns and compositions are related to asthma exacerbations. We collected nasal blow samples (n = 319) longitudinally during a clinical trial at 2 time-points within one year: randomization when asthma is under control, and at time of early loss of asthma control (yellow zone (YZ)). We report that participants whose microbiota was dominated by the commensal Corynebacterium + Dolosigranulum cluster at RD experience the lowest rates of YZs (p = 0.005) and have longer time to develop at least 2 episodes of YZ (p = 0.03). The airway microbiota have changed from randomization to YZ. A switch from the Corynebacterium + Dolosigranulum cluster at randomization to the Moraxella- cluster at YZ poses the highest risk of severe asthma exacerbation (p = 0.04). Corynebacterium's relative abundance at YZ is inversely associated with severe exacerbation (p = 0.002).

Noninferiority field trial for evaluation of efficacy of ciprofloxacin associated with internal teat sealant as dry-off protocol.

The aim of this study was to compare the efficacy of two dry-off protocols: (a) dry cow therapy using ciprofloxacin hydrochloride 400 mg followed by the administration of an internal teat sealant composed of 4 g of bismuth subnitrate, and (b) a positive control using dry cow therapy with 250 mg cephalonium followed by the administration of 2.6 g bismuth subnitrate internal teat sealant. A total of 578 Holstein cows selected from 7 commercial herds were randomly allocated into two groups at drying off: (a) ciprofloxacin hydrochloride 400 mg (CH) associated with ITS, n = 1112 mammary quarters/296 cows, or (b) positive control (PC) = cephalonium (250 mg) associated with ITS, n = 1058 mammary quarters/282 cows). A total of 1787 out of 2170 mammary quarters (82%) had negative culture at drying off. The microorganisms most frequently isolated at drying off were CNS (5.62%), Strep. uberis (1.9%), Corynebacterium spp. (1.8%), and Staphylococcus aureus (1.01%). A total of 465 mammary quarters experienced new intramammary infections (NIMIs), and the main microorganisms causing NIMI were CNS (21.94%), Strep. uberis (17.2%), and Pseudomonas spp. (9.7%). The CH protocol was not inferior to PC, as the cure risk of mammary quarters CH-treated was at the noninferiority limit. However, the mammary quarters treated by CH protocol had 24% and 31% lower risk of overall NIMI and NIMI caused by major pathogens, respectively, than mammary quarters dried with the PC protocol. In addition, the mammary quarters treated with CH protocol had a lower risk of CM through the first 60 DIM than those treated with PC protocol. Both DCT protocols showed similar odds of microbiological cure, but the CH protocol had greater prevention against NIMI during dry-off period.

Effects of Lactobacillus reuteri-containing lozenges on healing after surgical removal of mandibular third molars: a randomised controlled trial.

We investigated the effect of probiotic supplements on oral wound healing, swelling, pain and discomfort after surgical removal of mandibular third molars. A second aim was to evaluate if the intervention could influence the concentrations of oxytocin in saliva. Sixty-four consecutive volunteers (18-34 years) were enrolled to a double-blind randomised placebo-controlled trial with two parallel arms. Following surgery, the patients were asked to take three lozenges per day containing two strains of Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo for two weeks. The clinical healing and extra-oral swelling were scored two weeks post-operatively. Samples of wound exudate were cultivated for the presence of Staphylococcus aureus and ß-haemolytic streptococci. Salivary oxytocin concentrations were analysed from pre- and post-surgery samples using ELISA technique. Compliance and the subjective perception of swelling, pain and discomfort were reported daily through visual analogue scales in a logbook. All patients except three completed the protocol and the postoperative course was uneventful in most cases. Minor extra-oral swellings were noted in five patients, but none required antibiotic treatment. At the 2-week follow-up, there were no significant differences in clinical wound healing index, extra-oral swelling, bacterial growth or salivary oxytocin levels between the groups. The self-reported data unveiled, however, a significantly reduced sense of swelling, in particular during the second week after surgery in the probiotic test group (P<0.05). Likewise, significantly fewer nights with disturbed sleep and fewer days with sick-leave from work were reported among the participants in the test group (P<0.05). No differences were found in the post-operative use of analgesics. In conclusion, we found no significant influence of probiotic supplements on objective wound healing after surgical extraction of impacted mandibular third molars. However, since the patients' perceived significant post-operative ameliorations, further studies are needed to explore the patient's value of the intervention.

Bloodstream infections in hospitalized adults with dengue fever: Clinical characteristics and recommended empirical therapy.

BACKGROUND: Dengue is an important mosquito-borne tropical viral disease and dual infection, though rare, has been regarded as a risk factor for severe disease and mortality. However, few studies focused on bloodstream infections (BSIs) and empirical antibiotic therapy rarely addressed. METHODS: Dengue patients with concurrent or subsequent BSIs between July 1 and December 31, 2015 were included. Clinical information, laboratory data, and drug susceptibility data were collected. RESULTS: Totally 80 patients, with an in-hospital mortality rate of 32.5%, were included and categorized into three groups. 32 patients in Group I (BSI onset within 48 h after admission), 32 in Group II (between 48 h and one week), and 16 in Group III (more than one week). Patients in Group I were older (mean age: 75.6 vs. 72.6 or 69.6 years; P = 0.01) and had a higher Charlson comorbidity index (3.1 vs. 1.8 or 1.9; P = 0.02) than those in Group II or III. Streptococcus species (28.9%, 11/38) and Escherichia coli (23.7%, 9/38) were major pathogens in Group I. Enterobacteriaceae (38.2%, 13/34) isolates predominated in Group II. Fatal patients more often received inappropriate empirical antibiotic than the survivors (61.5% vs. 35.2%; P = 0.03). According to susceptibility data, pathogens in Group I and II shared similar susceptibility profiles, and levofloxacin, cefepime, or piperacillin/tazobactam, can be empirically prescribed for those hospitalized within one week. CONCLUSIONS: BSI pathogens vary among dengue patients. For adults with dengue and suspected BSI hospitalized within one week, empirical antimicrobial agents are recommended.

Effects of dietary supplementation with essential oils and organic acids on the growth performance, immune system, fecal volatile fatty acids, and microflora community in weaned piglets.

The present study was conducted to assess the effects of a mixture of essential oils and organic acids on the growth performance, immune system, major fecal volatile fatty acids (VFAs), and microflora community in the weaned piglets. We also evaluated the antibacterial activity of the essential oil mixture on Escherichia coli and Staphylococcus aureus. Three hundred weaned piglets (Duroc × Landrace × Yorkshire) were randomly divided into the following 3 treatment groups: basal diet (C), basal diet supplemented with the mixture of essential oils and organic acids (T1), and basal diet supplemented with antibiotics (T2). The mixture of essential oils and organic acids comprised of cinnamaldehyde (15%), thymol (5%), citric acid (10%), sorbic acid (10%), malic acid (6.5%), and fumaric acid (13.5%). In vitro studies showed that the mixture of essential oils extremely damaged the cell structure of pathogenic bacteria by deforming the membranes and disorganizing the intracellular components. In vivo studies revealed that diet supplementation with a mixture of essential oils and organic acids improved the final body weight and ADG of piglets (P < 0.05), increased the concentration of serum complement 4 (P < 0.05), and enhanced the fecal level of isovaleric acid (P < 0.05) compared with controls on day 28. Result of high-throughput sequencing revealed that: 1) a total of 1,177 and 1,162 observed taxonomic units (OTUs) were shared between all treatment groups on day 14 and 28, respectively; 2) the T1 exhibited higher (P < 0.05) beta diversity (unweighted UniFrac distance) than control and antibiotics treatment on day 28; 3) the samples in principle component analysis plot and tree of relative abundance were separated from each other based on dietary treatments and age; 4) Firmicutes and Bacteroidetes were the most 2 dominate phyla; Lactobacillus and Streptococcus were the 2 top species among the recognized microbiota; 5) T1 had higher (P < 0.05) relative abundance of Lactobacillus mucosae than control and antibiotics treatment on day 28. To conclude, the mixture of cinnamaldehyde and citric acids damaged the structure of pathogens in vitro; the mixture of essential oils and organic acids improved the growth performance, increased the fecal concentration of isovaleric acid, and modulated the microflora community in weaned piglets.

Isolation of Fully Vancomycin-Resistant Streptococcus thoraltensis from the Nasal Cavity of a Healthy Young Adult.

BACKGROUND: Streptococcus thoraltensis was first isolated from pigs and rabbits. Later, isolation from human oral and nasal cavities and from throat and oropharynx was documented. S. thoraltensis was isolated from patients with periodontitis, tonsillopharyngitis, and chorioamnionitis suggesting a possible pathological role in human infections. All S. thoraltensis isolates of animal and human origins were sensitive to vancomycin. METHODS: Standard microbiological identification methods, biochemical analysis, and antibiotic susceptibility testing using disk diffusion and E methods were used. Automatic species identification and antibiotic susceptibility testing were carried out using the Vitek 2 compact system. Molecular analysis of vancomycin resistance gene was carried out using a PCR with specific primers for vanA. RESULTS: We report a healthy young female adult, aged 19 years, with history of exposure to pet rabbit who had nasal colonization with S. thoraltensis. Identification of S. thoraltensis was based on traditional microbiological methods (culture, Gram stain, and biochemical tests), and the Vitek 2 compact system with 97% confidence rate. Antibiotic susceptibility testing of the isolate indicated resistance to most antibiotics, including penicillins, cephalosporins, methicillin, and glycopeptides. The minimal inhibitory concentration for vancomycin and teicoplanin was exceptionally high (>256 µg/mL). Molecular analysis indicated the absence of vanA gene in S. thoraltensis. CONCLUSION: We report for the first time the isolation of a fully vancomycin-resistant S. thoraltensis independent of vanA from a healthy human anterior nasal cavity. The pathological role of this newly identified organism with an exceptionally rare resistance pattern in human infections is yet to be identified.

Role of chemical and herbal dentifrices against indigenous oral Pathogens.

The oral cavity has its own significant micro-flora but under unhygienic conditions can cause infections or diseases like gingivitis, caries, plaque and gum bleeding. Out of more than 700 oral microbial species, some opportunistic pathogens such as Staphylococcus aureus, Streptococcus spp. and Candida albicans are more prevalent. In this study, the antimicrobial activities of various toothpastes (dilutions ranging from 1:1-1:128) against above mentioned pathogens were assessed. The pathogens were isolated from clinical samples using various differential and selective media and identified through microscopic examination, cultural characteristics and biochemical tests using both conventional and API kit system (Biomerieux, France). Antimicrobial activities of selected dentifrice formulations against identified microbes were determined using agar well diffusion and Minimum Inhibitory Concentration assays. Statistical analysis of the data on different variables has been performed by Analysis of Variance and Mean ±SD using SPSS software. From the collected samples Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius, Streptococcus intermedius and Candida albicans were isolated and identified. All the selected toothpastes showed significant (p<0.01) antimicrobial activity against the bacterial and fungal isolates. Variable results (inhibitory zone diameters ranging from 35.10±8.00 to 2.40±5.37) were found when mean of different dilutions were compared. Conventional dentifrices exhibited more inhibition as compared to herbal products.

Characterization of microbial community structure and metabolic potential using Illumina MiSeq platform during the black garlic processing.

Black garlic is a distinctive garlic deep-processed product made from fresh garlic at high temperature and controlled humidity. To explore microbial community structure, diversity and metabolic potential during the 12days of the black garlic processing, Illumina MiSeq sequencing technology was performed to sequence the 16S rRNA V3-V4 hypervariable region of bacteria. A total of 677,917 high quality reads were yielded with an average read length of 416bp. Operational taxonomic units (OTU) clustering analysis showed that the number of species OTUs ranged from 148 to 1974, with alpha diversity increasing remarkably, indicating the high microbial community abundance and diversity. Taxonomic analysis indicated that bacterial community was classified into 45 phyla and 1125 distinct genera, and the microbiome of black garlic samples based on phylogenetic analysis was dominated by distinct populations of four genera: Thermus, Corynebacterium, Streptococcus and Brevundimonas. The metabolic pathways were predicted for 16S rRNA marker gene sequences based on Kyoto Encyclopedia of Genes and Genomes (KEGG), indicating that amino acid metabolism, carbohydrate metabolism and membrane transport were important for the black garlic fermentation process. Overall, the study was the first to reveal microbial community structure and speculate the composition of functional genes in black garlic samples. The results contributed to further analysis of the interaction between microbial community and black garlic components at different stages, which was of great significance to study the formation mechanism and quality improvement of black garlic in the future.

Septic keratitis in dogs, cats, and horses in Switzerland: associated bacteria and antibiotic susceptibility.

OBJECTIVE: To evaluate the most common bacterial pathogens associated with septic keratitis in veterinary patients from Switzerland. The second objective was to analyze antibiotic susceptibility test results of the identified bacterial pathogens. The third objective was to evaluate potential breed predispositions to septic keratitis. PROCEDURES: Two hundred and fifty-five cultures and antibiotic susceptibility reports from dogs, cats, and horses with septic keratitis that were presented to the University of Zurich Veterinary Medical Teaching Hospital between 2009 and 2013 were reviewed. Odds ratios for the risk of having a septic keratitis were estimated for all dog and cat breeds compared to the general nonbrachycephalic hospital population. RESULTS: Ninety-six, 29, and 31 positive cultures were obtained from 89 canine, 28 feline, and 29 equine eyes, respectively. Repeat sampling accounted for the differences in numbers. Negative culture results were obtained in 50, 31, and 18 cases. Staphylococci and streptococci accounted for 66% of the isolates in dogs and 80% of the isolates in cats and horses. Staphylococcus spp. had a higher percentage of fluoroquinolone-resistant isolates compared to previous reports. Brachycephalic breeds had elevated odds ratios for the presence of septic keratitis. CONCLUSION: Identified bacterial pathogens and their prevalence as well as the elevated odds ratios for septic keratitis in brachycephalics are roughly consistent with previous studies. Based on systemic breakpoint data, resistance to commonly used topical antibiotics, including the second-generation fluoroquinolones, was found.

Antibacterial Efficacy of Mouthwash Prepared from Pomegranate, Grape Seed and Guava Extracts against Oral Streptococci: An in Vivo Study.

BACKGROUND: Pomegranate, Grape seed and Guava extracts have much been reviewed in Ayurveda and has been proven to have antibacterial action Aim: The objective of the study is to investigate and compare the mouthwash prepared from pomegranate, grape seed and guava extracts on salivary streptococci levels at the end of 48 hr and 7 days, of twice a day usage. STUDY DESIGN: 40 school going children aged 8-10 yrs, randomly allocated into 4 groups (n=10 for experimental group) were asked to rinse with a) Mouthwash prepared from Pomegranate extract, 15 ml twice a day b) Mouthwash prepared from Grape seed extract, 15 ml twice a day, c) Mouthwash prepared from guava extract, 15 ml twice a day, d) Control- Distil water, twice a day. The oral streptococci colony forming units/ml (CFU/ml) was assessed by inoculating the salivary samples on blood agar media at the end of 48 hrs, and 7 days. RESULTS AND CONCLUSION: the aqueous extracts of the chosen herbal plants showed an acceptable antibacterial efficacy against oral streptococci.

Empiric antibiotic protocols for cancer patients with neutropenia: a single-center study of treatment efficacy and mortality in patients with bacteremia.

BACKGROUND: There are several empiric antibiotic treatment options for febrile neutropenia, yet there is no universally-accepted initial protocol. We aimed to assess the performance of a protocol (piperacillin, gentamicin and cefazolin) introduced over 40 years ago and compare its coverage against bacteria isolated from blood of neutropenic patients with that of various commonly used antibiotic treatment protocols. METHODS: Adults with neutropenia admitted between 2003 and 2012 to the hemato-oncologic departments and in whom blood cultures were taken on admission were included. Appropriateness of several common antibiotic protocols was assessed based on the susceptibility of the blood isolates. Crude mortality rates were computed by the susceptibility of bacteria isolated from patients' blood to the actual treatment given. RESULTS: In total, 180 admissions of neutropenic patients (95 in patients who had fever above 38 °C) with positive blood cultures were analyzed. The actual antibiotic regimen prescribed was deemed appropriate in 82% of bacteremia episodes. The recommended institutional protocol was used in 62% of bacteremia episodes in neutropenic patients. This protocol would have been appropriate in 85% of all neutropenic bacteremia episodes and 89% of episodes in febrile neutropenia patients compared with piperacillin/tazobactam (79%, P = 0.13 and 76%, P = 0.002, respectively) and imipenem (93%, P = 0.004 and 92%, P = 0.74, respectively). Isolation of bacteria resistant to the actual antibiotic treatment given was associated with higher mortality at one week and at 30 days. CONCLUSION: Common current antibiotic regimens provide similar coverage among febrile neutropenic patients, whereas broad spectrum antibiotic combinations maximize coverage among neutropenic patients.

Persistence of antimicrobial resistance in respiratory streptococci.

OBJECTIVES: To assess whether persistence of antimicrobial resistance (i.e. non-susceptible resistance status) after treatment with penicillins or cephalosporins versus macrolides or tetracyclines differs and to compare the results obtained using routinely collected data with findings reported in prospective studies. METHODS: Routinely collected microbiological data from 14 voluntary participating laboratories (2005) containing information on resistance status and individual antimicrobial consumption patterns (mid 2004-2005) were analysed using a generalised estimating equation (GEE) approach. The link function was adjusted to acknowledge that the proportion of resistant isolates in the population not treated with antibiotics [baseline resistance (BR)] is not necessarily zero. To optimise the comparability of this study with prospective studies, the analysis was repeated after removal of 14 isolates from patients who did not survive 2005. RESULTS: BR estimates were unstable and their confidence intervals were wide, which called for a sensitivity analysis using an adjusted GEE model with three different BR estimates. All models indicated that the proportion of susceptible isolates differed by treatment group and increased significantly over time, with this increase being independent of treatment group. Persistence of resistance after exposure to macrolides or tetracyclines was approximately three times as long as after exposure to penicillins or cephalosporins. CONCLUSIONS: Resistance following treatment with macrolides or tetracyclines persists longer than following treatment with penicillins or cephalosporins, which confirms the findings from prospective studies and suggests the use of routinely collected data as a valuable alternative to determine such differences in persistence of resistance.

Evaluation of the antimicrobial efficacy of Minthostachys verticillata essential oil and limonene against Streptococcus uberis strains isolated from bovine mastitis.

Bovine mastitis is a disease that causes great economic losses per year, being Streptococcus uberis the main environmental pathogen involved. The aim of the present study was to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of Minthostachys verticillata essential oil and limonene for S. uberis strains isolated from bovine mastitis. In addition, the effect of MIC on biofilm formation was analyzed. MIC values for the essential oil ranged from 14.3 to 114.5mg/ml (1.56-12.5%v/v) and MBC between 114.5 and 229mg/ml (12.5-25%v/v). MICs for limonene ranged from 3.3 to 52.5mg/ml (0.39-6.25%v/v) and MBC was 210mg/ml (25%v/v). Both compounds showed antibacterial activity and affected the biofilm formation of most of the strains tested. In conclusion, these compounds could be used as an alternative and/or complementary therapy for bovine mastitis caused by S. uberis.

Evaluación de la eficacia antimicrobiana del aceite esencial de Minthostachys verticillata y limoneno contra cepas de Streptococcus uberis aislados de mastitis bovina / Evaluation of the antimicrobial efficacy of Minthostachys verticillata essential oil and limonene against Streptococcus uberis strains isolated from bovine mastitis

Bovine mastitis is a disease that causes great economic losses per year, being Streptococcus uberis the main environmental pathogen involved. The aim of the present study was to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of Minthostachys verticillata essential oil and limonene for S. uberis strains isolated from bovine mastitis. In addition, the effect of MIC on biofilm formation was analyzed. MIC values for the essential oil ranged from 14.3 to 114.5 mg/ml (1.56-12.5% v/v) and MBC between 114.5 and 229 mg/ml (12.5-25% v/v). MICs for limonene ranged from 3.3 to 52.5 mg/ml (0.39-6.25% v/v) and MBC was 210 mg/ml (25% v/v). Both compounds showed antibacterial activity and affected the biofilm formation of most of the strains tested. In conclusion, these compounds could be used as an alternative and/or complementary therapy for bovine mastitis caused by S. uberis.

La mastitis bovina es una enfermedad que causa grandes pérdidas económicas por año, Streptococcus uberis es el principal patógeno ambiental involucrado. El objetivo del presente estudio fue determinar la concentración inhibitoria mínima (CIM) y la concentración bactericida mínima (CBM) del aceite esencial de Minthostachys verticillata y del limoneno sobre cepas de S. uberis aisladas de mastitis bovina. Además, se analizó el efecto del aceite esencial y el limoneno en la CIM determinada en caso sobre la formación de biofilm de estas cepas. Los valores de CIM del aceite esencial oscilaron entre 14,3 y 114,5 mg/ml (1,56%-12,5% v/v) y los de CBM entre 114,5 y 229 mg/ml (12,5%-25% v/v). Las CIM del limoneno oscilaron entre 3,3 y 52,5 mg/ml (0,39% - 6,25% v/v) y la CBM fue de 210 mg/ml (25% v/v). Ambos compuestos mostraron actividad antibacteriana y afectaron la formación de biofilm de la mayoría de las cepas. En conclusión, estos compuestos podrían ser utilizados como terapia alternativa o complementaria para la mastitis bovina causada por S. uberis.

Short communication: Iodine concentrations in serum, milk, and tears after feeding Ascophyllum nodosum to dairy cows-A pilot study.

Kelp (Ascophyllum nodosum) is rich in iodine and often fed by organic dairy producers as a mineral supplement to support animal health. A commonly held belief is that kelp supplementation decreases susceptibility to infectious bovine keratoconjunctivitis due to increased iodine concentrations in tears. Whereas serum and milk iodine concentrations are positively correlated and modulated by oral iodine supplementation, nothing is known about the iodine concentration of tears. Therefore, the 3 objectives of this pilot study were to determine (1) the iodine content of tears, milk, and serum of cows after being fed kelp for 30d; (2) the trace mineral and thyroid status of cows before (d 0) and after being fed kelp for 30d; and (3) the in vitro growth rate of bacteria in tears (Moraxella bovis) or milk (Staphylococcus aureus, Escherichia coli, Streptococcus uberis) collected from cows fed no kelp (d 0) or kelp (d 30). Cows (n=3/treatment) were individually fed 56g of kelp per day (n=3/treatment) or not (n=3/no treatment) for 30 d. Daily feed intake of the TMR was recorded and weekly TMR, kelp, milk, blood and tear samples were collected and analyzed for iodine. The feed samples were pooled and further analyzed for other minerals. On d 0 and 30, liver biopsies and blood samples were collected and analyzed for mineral content and thyroid hormone concentrations, respectively. An inhibition test used milk and tear-soaked plates from kelp-fed cows (d 0 and 30) as well as 1 and 7.5% iodine as positive and distilled water as negative control. As expected, serum iodine concentrations were positively correlated with milk and tear iodine concentrations. Whereas the iodine concentrations in serum increased significantly in the kelp-fed cows during the 30-d study, milk and tear iodine concentrations increased only numerically in these cows compared with the control group. Liver mineral profiles were comparable between groups and generally did not change over the course of the study. Thyroid hormones remained overall within the reference range throughout the trial. Neither milk nor tears from kelp-fed cows inhibited in vitro growth of any of the plated bacteria. In summary, serum iodine concentration was correlated with the iodine concentration in milk and tears and feeding kelp increased only the serum iodine levels of cows in this trial. Bacterial growth was not inhibited in milk and tears of kelp-fed cattle in vitro, and prevention of infectious bovine keratoconjunctivitis would not be based solely on increased iodine concentrations in tears.

Impact of amoxicillin therapy on resistance selection in patients with community-acquired lower respiratory tract infections: a randomized, placebo-controlled study.

OBJECTIVES: To determine the effect of amoxicillin treatment on resistance selection in patients with community-acquired lower respiratory tract infections in a randomized, placebo-controlled trial. METHODS: Patients were prescribed amoxicillin 1 g, three times daily (n = 52) or placebo (n = 50) for 7 days. Oropharyngeal swabs obtained before, within 48 h post-treatment and at 28-35 days were assessed for proportions of amoxicillin-resistant (ARS; amoxicillin MIC ≥2 mg/L) and -non-susceptible (ANS; MIC ≥0.5 mg/L) streptococci. Alterations in amoxicillin MICs and in penicillin-binding-proteins were also investigated. ITT and PP analyses were conducted. RESULTS: ARS and ANS proportions increased 11- and 2.5-fold, respectively, within 48 h post-amoxicillin treatment compared with placebo [ARS mean increase (MI) 9.46, 95% CI 5.57-13.35; ANS MI 39.87, 95% CI 30.96-48.78; P < 0.0001 for both]. However, these differences were no longer significant at days 28-35 (ARS MI -3.06, 95% CI -7.34 to 1.21; ANS MI 4.91, 95% CI -4.79 to 14.62; P > 0.1588). ARS/ANS were grouped by pbp mutations. Group 1 strains exhibited significantly lower amoxicillin resistance (mean MIC 2.8 mg/L, 95% CI 2.6-3.1) than group 2 (mean MIC 9.3 mg/L, 95% CI 8.1-10.5; P < 0.0001). Group 2 strains predominated immediately post-treatment (61.07%) and although decreased by days 28-35 (30.71%), proportions remained higher than baseline (18.70%; P = 0.0004). CONCLUSIONS: By utilizing oropharyngeal streptococci as model organisms this study provides the first prospective, experimental evidence that resistance selection in patients receiving amoxicillin is modest and short-lived, probably due to 'fitness costs' engendered by high-level resistance-conferring mutations. This evidence further supports European guidelines that recommend amoxicillin when an antibiotic is indicated for community-acquired lower respiratory tract infections.

Autoinducer-2 detection among commensal oral streptococci is dependent on pH and boric acid.

Autoinducer-2, considered a universal signaling molecule, is produced by many species of bacteria; including oral strains. Structurally, autoinducer-2 can exist bound to boron (borated autoinducer-2). Functionally, autoinducer-2 has been linked to important bacterial processes such as virulence and biofilm formation. In order to test production of autoinducer-2 by a given bacterial strain, a bioassay using marine bioluminescent bacteria Vibrio harveyi as a reporter for autoinducer-2 has been designed. We hypothesize that pH adjustment and addition of boron are required for optimal bioluminescence and accurate autoinducer-2 detection. Using this reporter strain we tested autoinducer-2 activity from two oral commensal species, Streptococcus gordonii DL1 and Streptococcus oralis 34. Spent broth was collected and adjusted to pH 7.5 and supplemented with boric acid prior to measuring autoinducer- 2 activity. Results show that low pH inhibits bioluminescence of the reporter strain, but pH 7.5 allows for bioluminescence induction and proper readings of autoinducer-2 activity. Addition of boric acid also has a positive effect on bioluminescence allowing for a more sensitive detection of autoinducer-2 activity. Our data suggests that although autoinducer-2 is present in spent broth, low pH and/or low levels of boric acid become an obstacle for proper autoinducer-2 detection. For proper autoinducer-2 detection, we propose a protocol using this bioassay to include pH adjustment and boric acid addition to spent broth. Studies on autoinducer-2 activity in several bacteria species represent an important area of study as this universal signaling molecule is involved in critical bacterial phenotypes such as virulence and biofilm formation.