In VitroActivity of Ceftaroline-Avibactam against Gram-Negative and Gram-Positive Pathogens Isolated from Patients in Canadian Hospitals from 2010 to 2012: Results from the CANWARD Surveillance Study

ABSTRACTThein vitroactivities of ceftaroline-avibactam, ceftaroline, and comparative agents were determined for a collection of bacterial pathogens frequently isolated from patients seeking care at 15 Canadian hospitals from January 2010 to December 2012. In total, 9,758 isolates were tested by using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method (document M07-A9, 2012), with MICs interpreted by using CLSI breakpoints (document M100-S23, 2013). Ceftaroline-avibactam demonstrated potent activity (MIC90, ≤0.5 μg/ml) againstEscherichia coli,Klebsiella pneumoniae,Klebsiella oxytoca,Proteus mirabilis,Enterobacter cloacae,Enterobacter aerogenes,Serratia marcescens,Morganella morganii,Citrobacter freundii, andHaemophilus influenzae; >99% of isolates ofE. coli,K. pneumoniae,K. oxytoca,P. mirabilis,M. morganii,C. freundii, andH. influenzaewere susceptible to ceftaroline-avibactam according to CLSI MIC interpretative criteria for ceftaroline. Ceftaroline was less active than ceftaroline-avibactam against all species ofEnterobacteriaceaetested, with rates of susceptibility ranging from 93.9% (P. mirabilis) to 54.0% (S. marcescens). All isolates of methicillin-susceptibleStaphylococcus aureus(MIC90, 0.25 μg/ml) and 99.6% of methicillin-resistantS. aureusisolates (MIC90, 1 μg/ml) were susceptible to ceftaroline; the addition of avibactam to ceftaroline did not alter its activity against staphylococci or streptococci. All isolates ofStreptococcus pneumoniae(MIC90, 0.03 μg/ml),Streptococcus pyogenes(MIC90, ≤0.03 μg/ml), andStreptococcus agalactiae(MIC90, 0.015 μg/ml) tested were susceptible to ceftaroline. We conclude that combining avibactam with ceftaroline expanded its spectrum of activity to include most isolates ofEnterobacteriaceaeresistant to third-generation cephalosporins, including extended-spectrum β-lactamase (ESBL)- and AmpC-producingE. coliand ESBL-producingK. pneumoniae, while maintaining potent activity against staphylococci and streptococci.

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Activity of Ceftazidime-Avibactam against Fluoroquinolone-Resistant Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05136-14 ◽

2015 ◽

Vol 59 (6) ◽

pp. 3059-3065 ◽

Cited By ~ 14

Author(s):

C. Pitart ◽

F. Marco ◽

T. A. Keating ◽

W. W. Nichols ◽

J. Vila

Keyword(s):

Pseudomonas Aeruginosa ◽

Resistant Mutant ◽

Fluoroquinolone Resistance ◽

Cross Resistance ◽

Content Type ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method ◽

The Impact

ABSTRACTCeftazidime-avibactam and comparator antibiotics were tested by the broth microdilution method against 200Enterobacteriaceaeand 25Pseudomonas aeruginosastrains resistant to fluoroquinolones (including strains with the extended-spectrum β-lactamase [ESBL] phenotype and ceftazidime-resistant strains) collected from our institution. The MICs and mechanisms of resistance to fluoroquinolone were also studied. Ninety-nine percent of fluoroquinolone-resistantEnterobacteriaceaestrains were inhibited at a ceftazidime-avibactam MIC of ≤4 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference). Ceftazidime-avibactam was very active against ESBLEscherichia coli(MIC90of 0.25 mg/liter), ESBLKlebsiella pneumoniae(MIC90of 0.5 mg/liter), ceftazidime-resistant AmpC-producing species (MIC90of 1 mg/liter), non-ESBLE. coli(MIC90of ≤0.125 mg/liter), non-ESBLK. pneumoniae(MIC90of 0.25 mg/liter), and ceftazidime-nonresistant AmpC-producing species (MIC90of ≤0.5 mg/liter). Ninety-six percent of fluoroquinolone-resistantP. aeruginosastrains were inhibited at a ceftazidime-avibactam MIC of ≤8 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference), with a MIC90of 8 mg/liter. Additionally, fluoroquinolone-resistant mutants from each species tested were obtainedin vitrofrom two strains, one susceptible to ceftazidime and the other a β-lactamase producer with a high MIC against ceftazidime but susceptible to ceftazidime-avibactam. Thereby, the impact of fluoroquinolone resistance on the activity of ceftazidime-avibactam could be assessed. The MIC90values of ceftazidime-avibactam for the fluoroquinolone-resistant mutant strains ofEnterobacteriaceaeandP. aeruginosawere ≤4 mg/liter and ≤8 mg/liter, respectively. We conclude that the presence of fluoroquinolone resistance does not affectEnterobacteriaceaeandP. aeruginosasusceptibility to ceftazidime-avibactam; that is, there is no cross-resistance.

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In vitro activity of antimicrobial agents with and without sulbactam, EDTA and sulbactam-EDTA on ESBLs-producing Escherichia coli isolated from healthy Tibetan yaks

10.21203/rs.3.rs-39215/v1 ◽

2020 ◽

Author(s):

Baoguang Liu ◽

Xiaoling Yuan ◽

Yiheng Chen ◽

Xiaoshen Li ◽

Ming Bai ◽

...

Keyword(s):

Escherichia Coli ◽

Nasal Swab ◽

Antimicrobial Agents ◽

Synergistic Effects ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Third Generation Cephalosporins ◽

Enhance Activity

Abstract Background The spread of ESBLs-producing bacteria has been strikingly rapid in many regions of the world and it causes therapeutic difficulties in everyday practice. The aims of this study were to investigate the prevalence and susceptibilities of ESBLs-producing Escherichia coli isolates from healthy Tibetan yaks in China, to evaluate the activity of drug combinations on ESBLs-producing E. coli isolates. Methods From July 2018 to August 2019, a total of 750 nasal swab samples were tested for the presence of E. coli and ESBLs-producing strains. The MICs of 11 antimicrobial agents alone and combinations with sulbactam, EDTA or sulbactam-EDTA against 240 ESBLs-producing E.coli strains were determined by the broth microdilution method. Results Overall, 59.87% (n = 449) of the samples were positive for E. coli, 240 (53.45%) of 449 E. coli isolates were confirmed to be ESBLs-producing. The addition of sulbactam to the third generation cephalosporins, amikacin and fosfomycin for all isolates resulted in low MICs, increasing the level of susceptibility from 0, 0 and 0% to 50 ~ 87.5, 4.2 and 100% respectively. The addition of EDTA to fluoroquinolones, doxycycline, florfenicol, amikacin and fosfomycin, showed improved activities and resulted in low MICs, increasing the level of susceptibility from 0, 0, 8.3, 0 and 0% to 4.2 ~ 29.2, 33.3, 33.3, 66.7 and 45.8%, respectively. All other antibacterials (except fluoroquinolones, doxycycline and florfenicol), when combined with sulbactam-EDTA, were found to be more active than combinations only with sulbactam or with EDTA against most of isolates, with lower MIC50s and MIC90s. Conclusion In conclusion, ESBLs-producing E. coli isolates were widespread in healthy Tibetan yaks in China. ESBLs-producing E. coli isolates exhibited varying degrees of multidrug resistance. This study these findings suggested that sulbactam can enhance activity of β-lactams and some non-β-lactams of antimicrobial agents and had a synergistic effects with EDTA in improving activities of some families of antimicrobials.

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In Vitro Activity of Ceftaroline against Gram-Positive and Gram-Negative Pathogens Isolated from Patients in Canadian Hospitals in 2009

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01787-10 ◽

2011 ◽

Vol 55 (6) ◽

pp. 2837-2846 ◽

Cited By ~ 34

Author(s):

James A. Karlowsky ◽

Heather J. Adam ◽

Melanie R. DeCorby ◽

Philippe R. S. Lagacé-Wiens ◽

Daryl J. Hoban ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Klebsiella Oxytoca ◽

Canadian Hospital ◽

Gram Positive ◽

Gram Negative ◽

Content Type ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Recent Collection

ABSTRACTThein vitroactivities of ceftaroline and comparative agents were determined for a collection of the most frequently isolated bacterial pathogens from hospital-associated patients across Canada in 2009 as part of the ongoing CANWARD surveillance study. In total, 4,546 isolates from 15 sentinel Canadian hospital laboratories were tested using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Compared with other cephalosporins, including ceftobiprole, cefepime, and ceftriaxone, ceftaroline exhibited the greatest potency against methicillin-susceptibleStaphylococcus aureus(MSSA), with a MIC90of 0.25 μg/ml. Ceftaroline also demonstrated greater potency than ceftobiprole against community-associated methicillin-resistantS. aureus(MRSA) (MIC90, 0.5 μg/ml) and health care-associated MRSA (MIC90, 1 μg/ml) and was at least 4-fold more active than other cephalosporins againstStaphylococcus epidermidis; all isolates of MSSA and MRSA tested were susceptible to ceftaroline (MIC, ≤1 μg/ml). Against streptococci, includingStreptococcus pneumoniae, ceftaroline MICs (MIC90, ≤0.03 μg/ml) were comparable to those of ceftobiprole; however, against penicillin-nonsusceptible, macrolide-nonsusceptible, and multidrug-nonsusceptible isolates ofS. pneumoniae, ceftaroline demonstrated 2- to 4-fold and 4- to 16-fold more potent activities than those of ceftobiprole and ceftriaxone, respectively. All isolates ofS. pneumoniaetested were susceptible to ceftaroline (MIC, ≤0.25 μg/ml). Among Gram-negative isolates, ceftaroline demonstrated potent activity (MIC90, ≤0.5 μg/ml) againstEscherichia coli(92.2% of isolates were susceptible),Klebsiella pneumoniae(94.1% of isolates were susceptible),Proteus mirabilis(97.7% of isolates were susceptible), andHaemophilus influenzae(100% of isolates were susceptible). Ceftaroline demonstrated less potent activity (MIC90, ≥4 μg/ml) againstEnterobacterspp.,Acinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella oxytoca,Serratia marcescens, andStenotrophomonas maltophilia. Overall, ceftaroline demonstrated potentin vitroactivity against a recent collection of the most frequently encountered Gram-positive and Gram-negative isolates from patients attending hospitals across Canada in 2009.

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Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

International Journal of Antibiotics and Probiotics ◽

10.31405/ijap.1-2.17.03 ◽

2017 ◽

Vol 1 (2) ◽

pp. 48-60

Author(s):

A.G. Salmanov ◽

A.V. Rudenko

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Klebsiella Pneumoniae ◽

Staphylococcus Epidermidis ◽

Klebsiella Oxytoca ◽

Enterobacter Aerogenes ◽

Enterobacter Cloacae ◽

Proteus Vulgaris ◽

Providencia Rettgeri ◽

E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

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In VitroSynergistic Effect of Curcumin in Combination with Third Generation Cephalosporins against Bacteria Associated with Infectious Diarrhea

BioMed Research International ◽

10.1155/2014/561456 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 15

Author(s):

Nishanth Kumar Sasidharan ◽

Sreerag Ravikumar Sreekala ◽

Jubi Jacob ◽

Bala Nambisan

Keyword(s):

Synergistic Effect ◽

New Combination ◽

Normal Fibroblast ◽

Infectious Diarrhea ◽

Combination Drug ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Time Kill ◽

Third Generation Cephalosporins

Diarrhea is one of the leading causes of morbidity and mortality in humans in developed and developing countries. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of this infectious disease worldwide. Therefore, there exists a need to develop alternative natural or combination drug therapies. The aim of the present study was to investigate the synergistic effect of curcumin-1 in combination with three antibiotics against five diarrhea causing bacteria. The antibacterial activity of curcumin-1 and antibiotics was assessed by the broth microdilution method, checkerboard dilution test, and time-kill assay. Antimicrobial activity of curcumin-1 was observed against all tested strains. The MICs of curcumin-1 against test bacteria ranged from 125 to 1000 μg/mL. In the checkerboard test, curcumin-1 markedly reduced the MICs of the antibiotics cefaclor, cefodizime, and cefotaxime. Significant synergistic effect was recorded by curcumin-1 in combination with cefotaxime. The toxicity of curcumin-1 with and without antibiotics was tested against foreskin (FS) normal fibroblast and no significant cytotoxicity was observed. From our result it is evident that curcumin-1 enhances the antibiotic potentials against diarrhea causing bacteria inin vitrocondition. This study suggested that curcumin-1 in combination with antibiotics could lead to the development of new combination of antibiotics against diarrhea causing bacteria.

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In Vitro Activity of Eravacycline against Gram-Positive Bacteria Isolated in Clinical Laboratories Worldwide from 2013 to 2017

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01715-19 ◽

2019 ◽

Vol 64 (3) ◽

Cited By ~ 1

Author(s):

Ian Morrissey ◽

Stephen Hawser ◽

Sibylle H. Lob ◽

James A. Karlowsky ◽

Matteo Bassetti ◽

...

Keyword(s):

Antimicrobial Agents ◽

Clinical Isolates ◽

Gram Positive ◽

Content Type ◽

Gram Positive Bacteria ◽

Microdilution Method ◽

Clinical Laboratories ◽

Broth Microdilution Method ◽

Doubling Dilution

ABSTRACT Eravacycline is a novel, fully synthetic fluorocycline antibiotic being developed for the treatment of serious infections, including those caused by resistant Gram-positive pathogens. Here, we evaluated the in vitro activities of eravacycline and comparator antimicrobial agents against a recent global collection of frequently encountered clinical isolates of Gram-positive bacteria. The CLSI broth microdilution method was used to determine in vitro MIC data for isolates of Enterococcus spp. (n = 2,807), Staphylococcus spp. (n = 4,331), and Streptococcus spp. (n = 3,373) isolated primarily from respiratory, intra-abdominal, urinary, and skin specimens by clinical laboratories in 37 countries on three continents from 2013 to 2017. Susceptibilities were interpreted using both CLSI and EUCAST breakpoints. There were no substantive differences (a >1-doubling-dilution increase or decrease) in eravacycline MIC90 values for different species/organism groups over time or by region. Eravacycline showed MIC50 and MIC90 results of 0.06 and 0.12 μg/ml, respectively, when tested against Staphylococcus aureus, regardless of methicillin susceptibility. The MIC90 values of eravacycline for Staphylococcus epidermidis and Staphylococcus haemolyticus were equal (0.5 μg/ml). The eravacycline MIC90s for Enterococcus faecalis and Enterococcus faecium were 0.06 μg/ml and were within 1 doubling dilution regardless of the vancomycin susceptibility profile. Eravacycline exhibited MIC90 results of ≤0.06 μg/ml when tested against Streptococcus pneumoniae and beta-hemolytic and viridans group streptococcal isolates. In this surveillance study, eravacycline demonstrated potent in vitro activity against frequently isolated clinical isolates of Gram-positive bacteria (Enterococcus, Staphylococcus, and Streptococcus spp.), including isolates collected over a 5-year period (2013 to 2017), underscoring its potential benefit in the treatment of infections caused by common Gram-positive pathogens.

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Results from the China Antimicrobial Surveillance Network (CHINET) in 2017 of the In Vitro Activities of Ceftazidime-Avibactam and Ceftolozane-Tazobactam against Clinical Isolates of Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02431-18 ◽

2019 ◽

Vol 63 (4) ◽

Cited By ~ 19

Author(s):

Dandan Yin ◽

Shi Wu ◽

Yang Yang ◽

Qingyu Shi ◽

Dong Dong ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Clinical Isolates ◽

Surveillance Network ◽

Content Type ◽

Highly Active ◽

Microdilution Method ◽

Carbapenem Resistant ◽

Antimicrobial Surveillance ◽

Broth Microdilution Method

ABSTRACT The in vitro activities of ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C-T), and comparators were determined for 1,774 isolates of Enterobacteriaceae and 524 isolates of Pseudomonas aeruginosa collected by 30 medical centers from the China Antimicrobial Surveillance Network (CHINET) in 2017. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution method, and blaKPC and blaNDM were detected by PCR for all carbapenem-resistant Enterobacteriaceae (CRE). Ceftazidime-avibactam demonstrated potent activity against almost all Enterobacteriaceae (94.6% susceptibility; MIC50, ≤0.25 mg/liter; MIC90, ≤0.25 to >32 mg/liter) and good activity against P. aeruginosa (86.5% susceptibility; MIC50/90, 2/16 mg/liter). Among the CRE, 50.8% (189/372 isolates) were positive for blaKPC-2, which mainly existed in ceftazidime-avibactam-susceptible Klebsiella pneumoniae isolates (92.1%, 174/189). Among the CRE, 17.7% (66/372 isolates) were positive for blaNDM, which mainly existed in strains resistant to ceftazidime-avibactam (71.7%, 66/92). Ceftolozane-tazobactam showed good in vitro activity against Escherichia coli and Proteus mirabilis (MIC50/90, ≤0.5/2 mg/liter; 90.5 and 93.8% susceptibility, respectively), and the rates of susceptibility of K. pneumoniae (MIC50/90, 2/>64 mg/liter) and P. aeruginosa (MIC50/90, 1/8 mg/liter) were 52.7% and 88.5%, respectively. Among the CRE strains, 28.6% of E. coli isolates and 85% of K. pneumoniae isolates were still susceptible to ceftazidime-avibactam, but only 7.1% and 1.9% of them, respectively, were susceptible to ceftolozane-tazobactam. The rates of susceptibility of the carbapenem-resistant P. aeruginosa isolates to ceftazidime-avibactam (65.7%) and ceftolozane-tazobactam (68%) were similar. Overall, both ceftazidime-avibactam and ceftolozane-tazobactam were highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa recently collected across China, and ceftazidime-avibactam showed activity superior to that of ceftolozane-tazobactam against Enterobacteriaceae, whereas ceftolozane-tazobactam showed a better effect against P. aeruginosa.

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Arbekacin Activity against Contemporary Clinical Bacteria Isolated from Patients Hospitalized with Pneumonia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04839-14 ◽

2015 ◽

Vol 59 (6) ◽

pp. 3263-3270 ◽

Cited By ~ 17

Author(s):

Helio S. Sader ◽

Paul R. Rhomberg ◽

David J. Farrell ◽

Ronald N. Jones

Keyword(s):

The United States ◽

Multidrug Resistant ◽

Surveillance Program ◽

Content Type ◽

Microdilution Method ◽

Medical Centers ◽

Broth Microdilution Method ◽

Mrsa Strains ◽

Infection Types

ABSTRACTArbekacin is a broad-spectrum aminoglycoside licensed for systemic use in Japan and under clinical development as an inhalation solution in the United States. We evaluated the occurrence of organisms isolated from pneumonias in U.S. hospitalized patients (PHP), including ventilator-associated pneumonia (VAP), and thein vitroactivity of arbekacin. Organism frequency was evaluated from a collection of 2,203 bacterial isolates (339 from VAP) consecutively collected from 25 medical centers in 2012 through the SENTRY Antimicrobial Surveillance Program. Arbekacin activity was tested against 904 isolates from PHP collected in 2012 from 62 U.S. medical centers and 303 multidrug-resistant (MDR) organisms collected worldwide in 2009 and 2010 from various infection types. Susceptibility to arbekacin and comparator agents was evaluated by the reference broth microdilution method. The four most common organisms from PHP wereStaphylococcus aureus,Pseudomonas aeruginosa,Klebsiellaspp., andEnterobacterspp. The highest arbekacin MIC amongS. aureusisolates from PHP (43% methicillin-resistantS. aureus[MRSA]) was 4 μg/ml. AmongP. aeruginosaisolates from PHP, only one had an arbekacin MIC of >16 μg/ml (MIC50and MIC90, 1 and 4 μg/ml), and susceptibility rates for gentamicin, tobramycin, and amikacin were 88.0, 90.0, and 98.0%, respectively. Arbekacin (MIC50, 2 μg/ml) and tobramycin (MIC50, 4 μg/ml) were the most potent aminoglycosides tested againstAcinetobacter baumannii. AgainstEnterobacteriaceaefrom PHP, arbekacin and gentamicin (MIC50and MIC90, 0.25 to 1 and 1 to 8 μg/ml for both compounds) were generally more potent than tobramycin (MIC50and MIC90, 0.25 to 2 and 1 to 32 μg/ml) and amikacin (MIC50and MIC90, 1 to 2 and 2 to 32 μg/ml). Arbekacin also demonstrated potentin vitroactivity against a worldwide collection of well-characterized MDR Gram-negative and MRSA strains.

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Rosemary and Tea Tree Essential Oils Exert Antibiofilm Activities In Vitro against Staphylococcus aureus and Escherichia coli

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-337 ◽

2020 ◽

Vol 83 (7) ◽

pp. 1261-1267

Author(s):

TING LIU ◽

JINGFAN WANG ◽

XIAOMAN GONG ◽

XIAOXIA WU ◽

LIU LIU ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Essential Oil ◽

Biofilm Formation ◽

Gas Chromatography Mass Spectrometry ◽

Tea Tree ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method

ABSTRACT The purpose of the present study was to determine the bioactive compounds in rosemary essential oil (REO) and tea tree essential oil (TEO) and to investigate their antibacterial and antibiofilm activities against Staphylococcus aureus and Escherichia coli in vitro. The MIC and MBC assays were performed to assess the antibacterial activity of these two EOs against S. aureus and E. coli with the broth microdilution method. A crystal violet assay was used to ascertain the effects of EOs on the biofilm formation of the test strains, and a tetrazolium bromide (MTT) assay was used to measure the level of inactivation of mature biofilms by EOs. Gas chromatography–mass spectrometry revealed 15 compounds in REO and 27 compounds in TEO, representing 97.78 and 98.13% of the total EO, respectively. Eucalyptol and α-pinene were found in high concentrations in REO, and the two major compounds in TEO were 4-terpineol and terpinolene. The MICs of REO for the two S. aureus and E. coli test strains were both 0.5 mg/mL, and the MICs of TEO for the two strains were both 0.25 mg/mL. Therefore, these EOs can significantly inhibit the formation of biofilms and induced morphological biofilm changes, as verified by scanning electron microscopy. Both EOs had destructive effects on the mature biofilm of the two test strains. TEO was more inhibitory than REO for biofilm formation by the two test strains. HIGHLIGHTS

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Ceftaroline versus Isolates from Animal Bite Wounds: ComparativeIn VitroActivities against 243 Isolates, Including 156 Pasteurella Species Isolates

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01794-12 ◽

2012 ◽

Vol 56 (12) ◽

pp. 6319-6323 ◽

Cited By ~ 10

Author(s):

Ellie J. C. Goldstein ◽

Diane M. Citron ◽

C. Vreni Merriam ◽

Kerin L. Tyrrell

Keyword(s):

Pasteurella Multocida ◽

Active Agent ◽

Ceftaroline Fosamil ◽

Content Type ◽

Microdilution Method ◽

Bioactive Component ◽

Broth Microdilution Method ◽

Potential Clinical Utility ◽

Bite Wounds

ABSTRACTMore than 5 million Americans are bitten by animals, usually dogs, annually. Bite patients comprise ∼1% of all patients who visit emergency departments (300,000/year), and approximately 10,000 require hospitalization and intravenous antibiotics. Ceftaroline is the bioactive component of the prodrug ceftaroline fosamil, which is FDA approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs), including those containing methicillin-resistantStaphylococcus aureus(MRSA). There are noin vitrodata about the activity of ceftaroline againstPasteurella multocidasubsp.multocidaandPasteurella multocidasubsp.septica, otherPasteurellaspp., or other bite wound isolates. We therefore studied thein vitroactivity of ceftaroline against 243 animal bite isolates. MICs were determined using the broth microdilution method according to CLSI guidelines. Comparator drugs included cefazolin, ceftriaxone, ertapenem, ampicillin-sulbactam, azithromycin, doxycycline, and sulfamethoxazole-trimethoprim (SMX-TMP). Ceftaroline was the most active agent against all 5Pasteurellaspecies, includingP. multocidasubsp.multocidaandP. multocidasubsp.septica, with a maximum MIC of ≤0.008 μg/ml; more active than ceftriaxone and ertapenem (MIC90s, ≤0.015 μg/ml); and more active than cefazolin (MIC90, 0.5 μg/ml) doxycycline (MIC90, 0.125 μg/ml), azithromycin (MIC90, 0.5 μg/ml), ampicillin-sulbactam (MIC90, 0.125 μg/ml), and SMX-TMP (MIC90, 0.125 μg/ml). Ceftaroline was also very active against allS. aureusisolates (MIC90, 0.125 μg/ml) and otherStaphylococcusandStreptococcusspecies, with a maximum MIC of 0.125 μg/ml against all bite isolates tested. Ceftaroline has potential clinical utility against infections involvingP. multocida, otherPasteurellaspecies, and aerobic Gram-positive isolates, includingS. aureus.

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