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Rationale/Objectives: Antibiotic selection for in-hospital treatment of pulmonary exacerbations (PEx) in people with cystic fibrosis (CF) is typically guided by previous respiratory culture results or past PEx antibiotic treatment. In the absence of clinical improvement during PEx treatment, antibiotics are frequently changed in search of a regimen that better alleviates symptoms and restores lung function. The clinical benefits of changing antibiotics during PEx treatment are largely uncharacterized. Methods: This was a retrospective cohort study using the Cystic Fibrosis Foundation Patient Registry Pediatric Health Information System. PEx were included if they occurred in children with CF from 6 to 21 years old who had been treated with intravenous antibiotics between January 1, 2006, and December 31, 2018. PEx with lengths of stay <5 or >21 days or for which treatment was delivered in an intensive care unit were excluded. An antibiotic change was defined as the addition or subtraction of any intravenous antibiotic between Hospital Day 6 and the day before hospital discharge. Inverse probability of treatment weighting was used to adjust for disease severity and indication bias, which might influence a decision to change antibiotics. Results: In all, 4,099 children with CF contributed 18,745 PEx for analysis, of which 8,169 PEx (43.6%) included a change in intravenous antibiotics on or after Hospital Day 6. The mean change in pre- to post-treatment percent predicted forced expiratory volume in 1 second (ppFEV1) was 11.3 (standard error, 0.21) among events in which an intravenous antibiotic change occurred versus 12.2 (0.18) among PEx without an intravenous antibiotic change (P = 0.001). Similarly, the odds of return to ≤90% of baseline ppFEV1 were less for PEx with antibiotic changes than for those without changes (odds ratio [OR], 0.89 [95% confidence interval (CI), 0.80--0.98]). The odds of returning to ≤100% of baseline ppFEV1 did not differ between PEx with versus without antibiotic changes (OR, 0.94 [95% CI, 0.86--1.03]). In addition, PEx treated with intravenous antibiotic changes were associated with higher odds of future PEx (OR, 1.17 [95% CI, 1.12--1.22]). [ABSTRACT FROM AUTHOR]

Rationale: Pulmonary exacerbations (PExs) are associated with significant morbidity in people with cystic fibrosis (CF). Severe PExs are treated with intravenous antibiotics, including tobramycin. CF care guidelines recommend continuing chronic maintenance medications during PEx treatment. Azithromycin (AZM) is one of the most widely prescribed chronic medications for CF in the United States. Recent evidence has identified a potential antagonistic relationship between AZM and tobramycin.Objectives: To determine whether, among PEx treated with intravenous tobramycin, concomitant AZM use is associated with worse clinical outcomes.Methods: Retrospective cohort study using the CF Foundation Patient Registry-Pediatric Health Information System (CFFPR-PHIS)-linked dataset. People with CF age 6-21 years were included if they were hospitalized between 2006 and 2016 for a PEx. Inverse probability of treatment weighing was used to minimize the effects of confounders, including indication bias. Associations of concomitant treatment with AZM and lung function outcomes were determined using linear mixed-effect models and generalized estimating equations. Cox proportional hazard regression models were used to evaluate associations with time to next PEx.Results: Among the 10,660 people with CF included in the CFFPR-PHIS-linked dataset, 2,294 children and adolescents with 5,022 PExs that had intravenous tobramycin use were identified. A little less than half (n = 2,247; 45%) of all PExs were treated concomitantly with AZM and intravenous tobramycin. AZM use both at the most recent outpatient clinic encounter and during PEx treatment in combination with intravenous tobramycin was associated with a significantly lower absolute improvement in percentage-predicted forced expiratory volume in 1 second (ppFEV1) (-0.93%; 95% confidence interval [CI], -1.78 to -0.07; P = 0.033), a lesser odds of returning to 90% or more of baseline ppFEV1 (odds ratio, 0.79; 95% CI, 0.68-0.93; P = 0.003), and a shorter time to next PEx requiring intravenous antibiotics (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < 0.001) compared with intravenous tobramycin use without concomitant AZM.Conclusions: Concomitant AZM and intravenous tobramycin use for in-hospital PEx treatment was associated with poorer clinical outcomes than treatment with intravenous tobramycin without AZM. These results support the hypothesis that an antagonistic relationship between these two medications might exist. [ABSTRACT FROM AUTHOR]

Abstract: The enterococcal bacteriocin (enterocin) AS-48 is a broad-spectrum cyclic peptide. Enterocin AS-48 was tested against Bacillus coagulans in three vegetable canned foods: tomato paste (pH 4.64), syrup from canned peaches (pH 3.97), and juice from canned pineapple (pH 3.65). When vegetative cells of B. coagulans CECT (Spanish Type Culture Collection) 12 were inoculated in tomato paste supplemented with 6μg/ml AS-48 and stored at different temperatures, viable cell counts were reduced by approximately 2.37 (4°C), 4.3 (22°C) and 3.0 (37°C) log units within 24h storage. After 15-days storage, no viable cells were detected in any sample. Strain B. coagulans CECT 561 showed a poor survival in tomato paste, but surviving cells were also killed by AS-48. The bacteriocin was also very active against B. coagulans CECT 12 vegetative cells in juice from canned pineapple stored at 22°C, and slightly less active in syrup from canned peaches. In food samples supplemented with 1.5% lactic acid, enterocin AS-48 (6μg/ml) rapidly reduced viable counts of vegetative cells below detection limits within 24h storage. Addition of glucose and sucrose (10% and 20%) significantly increased bacteriocin activity against vegetative cells of B. coagulans CECT 12. Enterocin AS-48 had no significant effect on B. coagulans CECT 12 spores. However, the combined application of AS-48 and heat (80–95°C for 5min) significantly increased the effect of thermal treatments on spores. [Copyright &y& Elsevier]

Aims: To determine the activity of enterocin AS-48 against ropy-forming Bacillus licheniformis from cider. Methods and Results: Enterocin AS-48 was tested on B. licheniformis LMG 19409 from ropy cider in MRS-G broth, fresh-made apple juice and in two commercial apple ciders (A and B). Bacillus licheniformis was rapidly inactivated in MRS-G by 0·5 μg ml−1AS-48 and in fresh-made apple juice by 3 μg ml−1. Concentration-dependent inactivation of this bacterium in two commercial apple ciders (A and B) stored at 4, 15 and 30°C for 15 days was also demonstrated. Counts from heat-activated endospores in cider A plus AS-48 decreased very slowly. Application of combined treatments of heat (95°C) and enterocin AS-48 reduced the time required to achieved complete inactivation of intact spores in cider A to 4 min for 6 μg ml−1 and to 1 min for 12 μg ml−1. D and z values also decreased as the bacteriocin concentration increased. Conclusion: Enterocin AS-48 can inhibit ropy-forming B. licheniformis in apple cider and increase the heat sensitivity of spores. Significance and Impact of the Study: Results from this study support the potential use of enterocin AS-48 to control B. licheniformis in apple cider. [ABSTRACT FROM AUTHOR]

Aims: To characterize bacteriocin production, antimicrobial spectrum and plasmid content in bacteriocinogenic enterococci from foods. Methods and Results: Bacteriocinogenic Enterococcus faecium (14 isolates) and Enterococcus faecalis (three isolates) showed two different patterns of bacteriocin production in liquid broth: exponential-phase and stationary-phase production. Bacteriocin concentrates from all enterococci were inactivated by trypsin, but seldom by heat (100–117°C), extremes of pH (2·0 to 9·0) or reducing agents (such as dithiothreitol). All bacteriocin concentrates were active against Listeria innocua and Listeria monocytogenes, and most were also active against many Ent. faecalis and Ent. faecium isolates. Enterococci clustered in three main groups according to their plasmid content (which included plasmids from 2·0 to 53 kb). Several isolates from different foods showed almost identical plasmid profiles. The enterocin P structural gene ( entP) was detected by hybridization on plasmids of c. 19, 26 and/or 35–38 kb. Conclusions: Enterococci from food show different patterns of bacteriocin production and different plasmid content in spite of carrying similar bacteriocin-encoding genes. Significance and Impact of the Study: This study provides information on the diversity of bacteriocinogenic enterococci from food sources carrying apparently similar enterocin genes. [ABSTRACT FROM AUTHOR]

mª.t. garcía, r. lucas, h. abriouel, n. ben omar, r. pérez, mª.j. grande, m. martínez-cañamero and a. gálvez. 2004.Activity of the bacteriocin EJ97 produced byEnterococcus faecalisEJ97 against strains of‘ Bacillus macroides/B. maroccanus’ isolated from spoiled zucchini purée was investigated.The influence of several factors like bacteriocin concentration, incubation temperature, pH, growth medium and chemical perservatives on bacteriocin activity was investigated. Enterocin EJ97 [2 arbitrary units (AU) per millilitre] had a marked bactericidal effect on strain INRA P53-2 after 4 h of incubation at 37°C, 24 h at 15°C or 48 h at 4°C. Activity was markedly reduced at pH values of 5·0 and 9·0, but was potentiated by sodium nitrite, sodium benzoate, sodium lactate and sodium tripolyphosphate. Inhibition of strain INRA P53-2 in a commercial vegetable purée required a 10-fold higher bacteriocin concentration. Strain EJ97 was able to grow and produce bacteriocin on vegetable purée, but no inhibition of strain INRA P53-2 was detected.The concentration-dependent bactericidal activity of enterocin EJ97 against strain INRA P53-2 was higher at 37°C and neutral pH, and was potentiated by chemical preservatives. Although enterocin EJ97 was less active in vegetable purée, the concentrations providing bactericidal activity in this food matrix are practical for commercial use.Enterocin EJ97 may have a potential for use in the prevention of food spoilage caused by‘ B. macroides/B. maroccanus’. [ABSTRACT FROM AUTHOR]