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1

[Bacterial enteric pathogens' resistance to fluoroquinolones and last generation cephalosporines].  

PubMed

The increase of incidence of resistance to the antibiotics became the most worrisome subject within the clinical and research communities in the medical fields. Intrinsic resistance genetic mutations, horizontal transfer of mobile structures carrying genes coding for resistance to the antibiotics within the pan-microbial genome are representing the bacterial resistome which is bearing the genetic information regarding the defensive mechanisms developed by micro-organisms to protect themselves against antibiotics. Rice in the resistance of enteric bacteria, pathogens involved in a large number of human infections, to the cephalosporin of last generation and to the fluoroquinolones is a very actual subject in the medical area. Production of beta-lactamases with extended spectrum is the most important enzymatic defence system, developed by micro-organisms, consisting in the inactivation of beta-lactam antibiotics by destroying the beta-lactam ring. Enterobacteria are able to produce beta-lactamases of type TEM, SHV and/or CTX-M. Punctual mutations in nucleotide structure of bla genes, coding for beta-lactamases synthesis, are leading on production of a large diversity of enzymes with enlarged spectrum of activity (ESBL). At the beginning of 90's the first beta-lactamases resistance to clavulanic acid were detected and in our days more then 170 TEM, 120 SVH and 90 CTX-MESBLs are known. Escherichia coli strains are producing, firstly, TEM ESBLs, Klebsiella pneumoniae SHV ESBLs. and both are producing CTX-M type ESBLs, are resistant to the fluoroquinolones due to punctual mutations in nucleotide structure of gyr gene coding for gyrases production, enzymes involved in nucleic acids replication. Resistance to the antibiotics with extended activity is a public health threat due to their capacity of large spreading within bacterial population, when the coding structures are located on mobile genetic structures. The menace increase when genes coding for fluoroquinolones resistance (qnr) are identified on such of structures. PMID:21553476

Damian, Maria; Usein, Codru?a-Romanita; Palade, Andi Marian; B?ltoiu, M?d?lina; Condei, Maria; Ciontea, Simona; Tatu-Chi?oiu, Dorina

2010-01-01

2

Dramatic increase of third-generation cephalosporin-resistant E. coli in German intensive care units: secular trends in antibiotic drug use and bacterial resistance, 2001 to 2008  

Microsoft Academic Search

INTRODUCTION: The objective of the present study was to analyse secular trends in antibiotic consumption and resistance data from a network of 53 intensive care units (ICUs). METHODS: The study involved prospective unit and laboratory-based surveillance in 53 German ICUs from 2001 through 2008. Data were calculated on the basis of proportions of nonduplicate resistant isolates, resistance densities (that is,

Elisabeth Meyer; Frank Schwab; Barbara Schroeren-Boersch; Petra Gastmeier

2010-01-01

3

Regional intravenous versus systemic intravenous prophylactic administration of third-generation cephalosporins (ceftazidime and ceftriaxone) in elective foot surgery  

Microsoft Academic Search

The efficacy of a regional route for antibiotic prophylaxis in elective foot surgery was investigated in 20 patients and compared with the standard systemic intravenous method in 47 patients using two third-generation cephalosporins (ceftazidime and ceftriaxone). Each antibiotic (2 g) was given intravenously as the standard systemic prophylaxis at different intervals (10 min, 20 min, 2 h and 4 h)

E. Dounis; S. Tsourvakas; L. Kalyvas; P. Tzivelekis; E. Papakalou; H. Giamarellou

1995-01-01

4

Tetracycline derivatives and ceftriaxone, a cephalosporin antibiotic, protect neurons against apoptosis induced by ionizing radiation.  

PubMed

DNA damage induced by low doses of ionizing radiation causes apoptosis, which is partially mediated via the generation of free radicals. Both free radicals and apoptosis are involved in the majority of brain diseases, including stroke, Alzheimer's disease and amyotrophic lateral sclerosis. Because previous studies have shown that tetracycline derivatives doxycycline and minocycline have anti-inflammatory effects and are protective against brain ischemia, we studied whether minocycline and doxycycline or ceftriaxone, a cephalosporin antibiotic with the potential to inhibit excitotoxicity, protect neurons against ionizing radiation in primary cortical cultures. A single dose of 1 Gy significantly increased lactate dehydrogenase release, induced DNA fragmentation in neurons and triggered microglial proliferation. Treatment with minocycline (20 nM), doxycycline (20 nM) and ceftriaxone (1 microM) significantly reduced irradiation-induced lactate dehydrogenase release and DNA fragmentation. The most efficient protection was achieved by minocycline treatment, which also inhibited the irradiation-induced increase in microglial cell number. Our results suggest that some tetracycline derivatives, such as doxycycline and minocycline, and ceftriaxone, a cephalosporin derivative, protect neurons against apoptotic death. PMID:11579149

Tikka, T; Usenius, T; Tenhunen, M; Keinänen, R; Koistinaho, J

2001-09-01

5

In vitro activity of cefquinome, a new cephalosporin, compared with other cephalosporin antibiotics.  

PubMed

The in vitro activity of cefquinome, a new aminothiazolyl cephalosporin with a C-3 bicyclic pyridinium group, was compared with ceftazidime, cefpirome, and cefepime. Cefquinome inhibited members of the Enterobacteriaceae at less than or equal to 0.5 microgram/ml for Escherichia coli, Klebsiella pneumoniae, K. oxytoca, Citrobacter diversus, Salmonella Shigella, Proteus mirabilis, Morganella, and Providencia. Although most Citrobacter freundii and Enterobacter cloacae were inhibited by less than 2 micrograms/ml, some strains resistant to ceftazidime were resistant, [minimum inhibitory concentration (MIC) greater than 16 micrograms/ml]. Serratia marcescens were inhibited by less than 1 microgram/ml and Pseudomonas aeruginosa by 8 micrograms/ml similar to the activity of cefepime. The majority of Haemophilus influenzae and Neisseria gonorrhoeae were inhibited by less than 0.25 microgram/ml. Most enterococci had cefquinome MICs of 4-8 micrograms/ml. Cefquinome was extremely active against group-A streptococci and Streptococcus pneumoniae with MICs less than 0.12 microgram/ml. 90% of methicillin-susceptible Staphylococcus aureus 90% were inhibited by 2 micrograms/ml. Overall, the in vitro activity of cefquinome was comparable with aminothiazolyl cephalosporins. It inhibited some Enterobacter and Citrobacter freundii resistant to ceftazidime as did cefpirome and cefepime. Cefquinome was not destroyed by the common plasmid beta-lactamases TEM-1, TEM-2, SHV-1, or by the chromosomal beta-lactamases of Klebsiella, Branhamella, and Pseudomonas, but it was hydrolyzed by TEM-3, TEM-5, and TEM-9. Its activity was not adversely decreased in different medium or protein, and minimum bactericidal concentrations (MBCs) for most species except for Enterobacter were within a dilution of MICs. PMID:1611848

Chin, N X; Gu, J W; Fang, W; Neu, H C

1992-01-01

6

Increasing use of third-generation cephalosporins for pneumonia in the emergency department: may some prescriptions be avoided?  

PubMed

Third-generation cephalosporins are used to treat inpatients with community-acquired pneumonia. Some of these prescriptions may be avoided, i.e. replaced by agents less likely to promote ESBL-mediated resistance. Our objectives were to assess the recent trend of third-generation cephalosporins use for pneumonia in the emergency department, and the proportion of avoidable prescriptions. This was a retrospective study of patients treated for community-acquired pneumonia in an emergency department, and subsequently hospitalized in non ICU wards. Third-generation cephalosporin prescriptions were presumed unavoidable if they met both criteria: (i) age???65 yr or comorbid condition, and (ii) allergy or intolerance to penicillin, or failure of penicillin first-line therapy, or treatment with penicillin in three previous months. Prescriptions were otherwise deemed avoidable. The proportion of patients treated with a third generation cephalosporin increased significantly from 13.9 % (6.9-24.1 %) in 2002 to 29.5 % (18.5-42.6 %) in 2012 (OR?=?1.07 [1.01-1.14] , P?=?0.02). This increase was independent from other factors associated with the prescription of a third-generation cephalosporin (immunocompromising condition, antibacterial therapy in three previous months, fluid resuscitation and REA-ICU class). Treatment with third-generation cephalosporin was avoidable in 118 out of 147 patients (80.3 % [72.7-86.2 %]). On day 7 after admission in the ED, treatment with third-generation cephalosporins was stopped or de-escalated in, respectively, 17 % and 32 % of patients. Antibiotic stewardship programs should be implemented to restrict the third-generation cephalosporins use for pneumonia in the emergency department. PMID:24442608

Goffinet, N; Lecadet, N; Cousin, M; Peron, C; Hardouin, J-B; Batard, E; Montassier, E

2014-07-01

7

Ceftriaxone, an FDA-approved cephalosporin antibiotic, suppresses lung cancer growth by targeting Aurora B  

PubMed Central

Ceftriaxone, an FDA-approved third-generation cephalosporin antibiotic, has antimicrobial activity against both gram-positive and gram-negative organisms. Generally, ceftriaxone is used for a variety of infections such as community-acquired pneumonia, meningitis and gonorrhea. Its primary molecular targets are the penicillin-binding proteins. However, other activities of ceftriaxone remain unknown. Herein, we report for the first time that ceftriaxone has antitumor activity in vitro and in vivo. Kinase profiling results predicted that Aurora B might be a potential ‘off’ target of ceftriaxone. Pull-down assay data confirmed that ceftriaxone could bind with Aurora B in vitro and in A549 cells. Furthermore, ceftriaxone (500 µM) suppressed anchorage-independent cell growth by targeting Aurora B in A549, H520 and H1650 lung cancer cells. Importantly, in vivo xenograft animal model results showed that ceftriaxone effectively suppressed A549 and H520 lung tumor growth by inhibiting Aurora B. These data suggest the anticancer efficacy of ceftriaxone for the treatment of lung cancers through its inhibition of Aurora B. PMID:22962305

Li, Xiang; Li, Haitao; Li, Shengqing; Zhu, Feng; Dong, Zigang

2012-01-01

8

Cefdinir: An advanced-generation, broad-spectrum oral cephalosporin  

Microsoft Academic Search

Background: Cefdinir is an advanced-generation, broad-spectrum cephalosporin antimicrobial agent that has been approved for the treatment of community-acquired pneumonia, acute bacterial exacerbations of chronic bronchitis, acute maxillary sinusitis, pharyngitis\\/tonsillitis, acute bacterial otitis media, and uncomplicated skin and skin-structure infections in adult and pediatric patients.Objective: The purpose of this article was to review the in vitro antimicrobial activity, pharmacokinetics, clinical efficacy,

David R. P. Guay

2002-01-01

9

Feasibility and impact of an intensified antibiotic stewardship programme targeting cephalosporin and fluoroquinolone use in a tertiary care university medical center  

PubMed Central

Background Restricted use of third-generation cephalosporins and fluoroquinolones has been linked to a reduced incidence of hospital-acquired infections with multidrug-resistant bacteria. We implemented an intensified antibiotic stewardship (ABS) programme in the medical service of a university hospital center aiming at a reduction by at least 30% in the use of these two drug classes. Methods The ABS programme was focused on the 300-bed medical service. Prescription of third-generation cephalosporins was discouraged, whereas the use of penicillins was encouraged. Monthly drug use density was measured in WHO-ATC defined and locally recommended daily doses (DDD and RDD) per 100 patient days, to evaluate trends before (01/2008 to 10/2011) and after starting the intervention (1/2012 to 3/2013). The effect was analysed using interrupted time-series analysis with six non-intervention departments as controls. Results Following initiation of the ABS intervention, overall antibiotic use in the medical service declined (p?cephalosporins and fluoroquinolones (p?cephalosporin use reductions (p?cephalosporins from 16.3 to 10.3 (?37%) and for fluoroquinolones from 17.7 to 10.1 (?43%), respectively. During the same period, the use of penicillins increased (15.4 to 18.2; 18%). The changes in expenditures for antibiotics in the medical service compared to control services minus programme costs indicated initial net cost savings likely to be associated with the programme. Conclusion An intensified ABS programme targeting cephalosporin und fluoroquinolone use in the setting of a large academic hospital is feasible and effective. The intervention may serve as a model for other services and hospitals with a similar structure and baseline situation. PMID:24731220

2014-01-01

10

Efficacy of treatment with carbapenems and third-generation cephalosporins for patients with febrile complicated pyelonephritis  

Microsoft Academic Search

The purpose of this study was to clarify the clinical relevance of carbapenem and third-generation cephalosporin treatment\\u000a for febrile complicated pyelonephritis, which often leads to urosepsis. Parenteral antimicrobial treatment with a carbapenem\\u000a or third-generation cephalosporin was administered to febrile patients and the treatment was switched to oral antimicrobial\\u000a agents after they became afebrile. In principle, the duration of the course

Satoshi Takahashi; Yuichiro Kurimura; Koh Takeyama; Kohei Hashimoto; Shintaro Miyamoto; Kohji Ichihara; Manabu Igarashi; Jiro Hashimoto; Ryoji Furuya; Hiroshi Hotta; Kohsuke Uchida; Noriomi Miyao; Masahiro Yanase; Yoshio Takagi; Hitoshi Tachiki; Keisuke Taguchi; Taiji Tsukamoto

2009-01-01

11

Efficacy of treatment with carbapenems and third-generation cephalosporins for patients with febrile complicated pyelonephritis.  

PubMed

The purpose of this study was to clarify the clinical relevance of carbapenem and third-generation cephalosporin treatment for febrile complicated pyelonephritis, which often leads to urosepsis. Parenteral antimicrobial treatment with a carbapenem or third-generation cephalosporin was administered to febrile patients and the treatment was switched to oral antimicrobial agents after they became afebrile. In principle, the duration of the course of antimicrobial chemotherapy was limited to a total of 14 days. Clinically, the success rates were 97.3% in the carbapenem group and 96.0% in the third-generation cephalosporin group. For microbiological efficacy, the success rates were 89.2% in the carbapenem group and 92.0% in the third-generation cephalosporin group. There were no serious adverse events in the course of the study. The treatment regimen with a carbapenem or a third-generation cephalosporin was highly effective for patients with febrile complicated pyelonephritis and was well tolerated. Either of these regimens could become one of the standard treatments for patients with febrile complicated pyelonephritis. PMID:20012730

Takahashi, Satoshi; Kurimura, Yuichiro; Takeyama, Koh; Hashimoto, Kohei; Miyamoto, Shintaro; Ichihara, Kohji; Igarashi, Manabu; Hashimoto, Jiro; Furuya, Ryoji; Hotta, Hiroshi; Uchida, Kohsuke; Miyao, Noriomi; Yanase, Masahiro; Takagi, Yoshio; Tachiki, Hitoshi; Taguchi, Keisuke; Tsukamoto, Taiji

2009-12-01

12

In Vitro and In Vivo Activity of First Generation Cephalosporins Against Leptospira  

PubMed Central

Third generation cephalosporins are commonly used in the treatment of leptospirosis. The efficacy of first generation cephalosporins has been less well-studied. Susceptibility testing of 13 Leptospira strains (11 serovars) to cefazolin and cephalexin was conducted using broth microdilution. Median minimal inhibitory concentration (MIC) for cefazolin and cephalexin ranged from < 0.016 to 2 ?g/mL (MIC90 = 0.5 ?g/mL) and from 1 to 8 ?g/mL (MIC90 = 8 ?g/mL), respectively. Efficacy of cefazolin and cephalexin in an acute lethal hamster model of leptospirosis was studied. Survival rates for cefazolin were 80%, 100%, and 100%, and survival rates for cephalexin were 50%, 80%, and 100% (treated with 5, 25, and 50 mg/kg per day for 5 days, respectively). Each treatment group showed improved survival compared with no treatment (P < 0.01), and none of the therapies, regardless of dose, was statistically significantly different than doxycycline. These results support a potential role for first generation cephalosporins as alternative therapies for leptospirosis. PMID:22049047

Harris, Brande M.; Blatz, Peter J.; Hinkle, Mary K.; McCall, Suzanne; Beckius, Miriam L.; Mende, Katrin; Robertson, Janelle L.; Griffith, Matthew E.; Murray, Clinton K.; Hospenthal, Duane R.

2011-01-01

13

In Vitro Activity of TD-1792, a Multivalent Glycopeptide-Cephalosporin Antibiotic, against 377 Strains of Anaerobic Bacteria and 34 Strains of Corynebacterium Species  

PubMed Central

TD-1792 is a multivalent glycopeptide-cephalosporin heterodimer antibiotic with potent activity against Gram-positive bacteria. We tested TD-1792 against 377 anaerobes and 34 strains of Corynebacterium species. Against nearly all Gram-positive strains, TD-1792 had an MIC90 of 0.25 ?g/ml and was typically 3 to 7 dilutions more active than vancomycin and daptomycin. PMID:22290981

Citron, Diane M.; Warren, Yumi A.; Goldstein, Ellie J. C.

2012-01-01

14

The intramammary efficacy of first generation cephalosporins against Staphylococcus aureus mastitis in mice.  

PubMed

Staphylococcus aureus-induced mastitis in cattle causes important financial losses in the dairy industry due to lower yield and bad milk quality. Although S. aureus is susceptible to many antimicrobials in vitro, treatment often fails to cure the infected udder. Hence, comprehensive evaluation of antimicrobials against S. aureus mastitis is desirable to direct treatment strategies. The mouse mastitis model is an elegant tool to evaluate antimicrobials in vivo while circumventing the high costs associated with bovine experiments. An evaluation of the antimicrobial efficacy of the intramammary (imam) applied first generation cephalosporins cefalexin, cefalonium, cefapirin and cefazolin, was performed using the S. aureus mouse mastitis model. In vivo determination of the effective dose 2log(10) (ED(2log10)), ED(4log10), protective dose 50 (PD(50)) and PD(100) in mouse mastitis studies, support that in vitro MIC data of the cephalosporins did not fully concur with the in vivo clinical outcome. Cefazolin was shown to be the most efficacious first generation cephalosporin to treat S. aureus mastitis whereas the MIC data indicate that cefalonium and cefapirin were more active in vitro. Changing the excipient for imam application from mineral oil to miglyol 812 further improved the antimicrobial efficacy of cefazolin, confirming that the excipient can influence the in vivo efficacy. Additionally, statistical analysis of the variation of S. aureus-infected, excipient-treated mice from fourteen studies emphasizes the strength of the mouse mastitis model as a fast, cost-effective and highly reproducible screening tool to assess the efficacy of antimicrobial compounds against intramammary S. aureus infection. PMID:22677480

Demon, Dieter; Ludwig, Carolin; Breyne, Koen; Guédé, David; Dörner, Julia-Charlotte; Froyman, Robrecht; Meyer, Evelyne

2012-11-01

15

Community-acquired upper respiratory tract infections and the role of third-generation oral cephalosporins.  

PubMed

Common community-acquired infections include those of the upper respiratory tract. In the 1990s, the antimicrobial treatment of upper respiratory tract infections focused on penicillin-resistant Streptococcus pneumoniae. However, following the introduction of a pneumococcal conjugate vaccine, a decrease in invasive pneumococcal disease occurred, and in the case of otitis media a shift towards Haemophilus influenzae as the predominant causative pathogen was observed. Future antimicrobial therapy for outpatient upper respiratory tract infections may need to focus on pathogens such as penicillin-susceptible S. pneumoniae, beta-lactamase-producing H. influenzae, beta-lactamase-negative amoxicillin-resistant H. influenzae and Moraxella catarrhalis. In these circumstances, third-generation oral cephalosporins, such as cefixime and cefdinir, could be increasingly used as an optional first-line therapy in community practice for upper respiratory tract infections suspected to be caused by these key pathogens, as an alternative to amoxicillin-clavulanate. PMID:20014898

Hedrick, James A

2010-01-01

16

Ceftriaxone versus Other Cephalosporins for Perioperative Antibiotic Prophylaxis: A Meta-Analysis of 43 Randomized Controlled Trials  

Microsoft Academic Search

The efficacy of ceftriaxone versus other cephalosporins in the perioperative prophylaxis of surgical wound, urinary tract and respiratory tract infections was compared in a meta-analysis of randomized controlled trials published between 1986 and 1996, identified from the Medline, Embase, SIGLE, ROPU, DHSS-Data and Medikat Cologne databases. Studies were grouped by type of infection, operative specialty, wound classification, study quality and

Eva Susanne Dietrich; Ute Bieser; Uwe Frank; Guido Schwarzer; Franz D. Daschner

2002-01-01

17

Cefotetan: a second-generation cephalosporin active against anaerobic bacteria. Committee on Antimicrobial Agents, Canadian Infectious Disease Society.  

PubMed Central

OBJECTIVE: To offer guidelines for the use of cefotetan, a cephamycin antibiotic, in order to minimize its overprescription. OPTIONS: Clinical practice options considered were treatment of infections with the use of second- and third-generation cephalosporins, carbapenems such as imipenem as well as combination regimens of agents active against anaerobic bacteria, such as metronidazole or clindamycin with an aminoglycoside. OUTCOMES: In order of importance: efficacy, side effects and cost. EVIDENCE: A MEDLINE search of articles published between January 1982 and December 1993. In-vitro and pharmacokinetic studies published in recognized peer-reviewed journals that used recognized standard methods with appropriate controls were reviewed. For results of clinical trials, the reviewers emphasized randomized double-blind trials with appropriate controls. VALUES: The Antimicrobial Agents Committee of the Canadian Infectious Disease Society (CIDS) and a recognized expert (M.J.G.) recommended use of cefotetan to prevent and treat infections against which it has proved effective in randomized controlled trials. BENEFITS, HARMS AND COSTS: These guidelines should lead to less inappropriate prescribing of cefotetan, with its attendant costs and risk of development of resistant bacteria. RECOMMENDATIONS: Cefotetan could be considered an alternative single agent for prophylaxis of infection in patients undergoing elective bowel surgery. It may be used to treat patients with acute pelvic inflammatory disease and endometritis. VALIDATION: This article was prepared, reviewed and revised by the Committee on Antimicrobial Agents of the CIDS. It was then reviewed by the Council of the CIDS, and any further necessary revisions were made by the chairman of the committee. PMID:8069799

Gribble, M J

1994-01-01

18

Characterization of third-generation cephalosporin-resistant Escherichia coli from bloodstream infections in Denmark.  

PubMed

The aim of the study was to investigate the molecular epidemiology of 87 third-generation cephalosporin-resistant Escherichia coli (3GC-R Ec) from bloodstream infections in Denmark from 2009. Sixty-eight of the 87 isolates were extended-spectrum beta-lactamase (ESBL) producers, whereas 17 isolates featured AmpC mutations only (without a coexpressed ESBL enzyme) and 2 isolates were producing CMY-22. The majority (82%) of the ESBL-producing isolates in our study were CTX-M-15 producers and primarily belonged to phylogroup B2 (54.4%) or D (23.5%). Further, one of the two CMY-22-producing isolates belonged to B2, whereas only few of the other AmpCs isolates belonged to B2 and D. Pulsed-field gel electrophoresis revealed that both clonal and nonclonal spread of 3GC-R Ec occurred. ST131 was detected in 50% of ESBL-producing isolates. The remaining ESBL-producing isolates belonged to 17 other sequence types (STs), including several other internationally spreading STs (e.g., ST10, ST69, and ST405). The majority (93%) of the ESBL-producing isolates and one of the CMY-22-producing isolates were multiresistant. In conclusion, 3GC-R in bacteriaemic E. coli in Denmark was mostly due to ESBL production, overexpression of AmpC, and to a lesser extent to plasmid-mediated AmpC. The worldwide disseminated CTX-M-15-ST131 was strongly represented in this collection of Danish, bacteriaemic E. coli isolates. PMID:24517383

Hansen, Frank; Olsen, Stefan S; Heltberg, Ole; Justesen, Ulrik S; Fuglsang-Damgaard, David; Knudsen, Jenny D; Hammerum, Anette M

2014-08-01

19

Study on gamma and electron beam sterilization of third generation cephalosporins cefdinir and cefixime in solid state  

NASA Astrophysics Data System (ADS)

The effect of gamma radiation from 60Co source and 2 MeV e-beam was studied on two thermolabile cephalosporin antibiotics viz cefdinir and cefixime in solid state. The parameters studied to assess radiolytic degradation were loss of chemical and microbiological potency, change in optical rotation, electronic and vibrational absorption characteristics, thermal behavior and color modification. ESR spectroscopic study, HPLC related impurity profile, thermogram and Raman spectrum are applied in deducing the nature of radiolytic impurities and their formation hypotheses. Cefixime is radiation sensitive, whereas cefdinir has acceptable radiation resistance at 25 kGy dose. The nature of radiolytic related impurities and their concentrations indicates that the lactam ring is not highly susceptible to direct radiation attack, which otherwise is considered very sensitive to stress (thermal, chemical and photochemical).

Singh, Babita K.; Parwate, Dilip V.; Das Sarma, Indrani B.; Shukla, Sudhir K.

2010-10-01

20

Cidal activity of oral third-generation cephalosporins against Streptococcus pneumoniae in relation to cefotaxime intrinsic activity.  

PubMed

This study explores the killing kinetics within 12 h of four oral third-generation cephalosporins against ten Streptococcus pneumoniae strains exhibiting cefotaxime minimum inhibitory concentrations (MICs) from 0.03 to 2 microg/ml. Killing curves were performed with concentrations achievable in serum after standard doses (0.015-4 microg/ml). Reductions of 90% were achieved with all compounds at serum-achievable concentrations for strains exhibiting cefotaxime MIC < or = 0.5 microg/ml. Against strains with cefotaxime MIC > or = 1 microg/ml, only cefditoren reached a 90% reduction with concentrations of 0.5-1 microg/ml doses. At 4 microg/ml, cefditoren and cefotaxime reached 99.9% reduction in seven of the ten strains studied. At serum-achievable concentrations, cefdinir and cefixime were not bactericidal against strains exhibiting cefotaxime MIC > or = 0.25 microg/ml and > or = 0.5 microg/ml, respectively. Cefditoren showed the best killing kinetic profiles and this observation may be important when choosing an oral third-generation cephalosporin as initial or sequential therapy. PMID:18299905

Cafini, F; Aguilar, L; Alou, L; Giménez, M J; Sevillano, D; Torrico, M; González, N; Granizo, J J; Martín-Herrero, J E; Prieto, J

2008-08-01

21

Influence of penicillin/amoxicillin non-susceptibility on the activity of third-generation cephalosporins against Streptococcus pneumoniae.  

PubMed

To study the influence of penicillin/amoxicillin non-susceptibility on the activity of third-generation cephalosporins, 430 consecutive penicillin non-susceptible Streptococcus pneumoniae 2007 isolates received in the Spanish Reference Pneumococcal Laboratory were tested. For comparative purposes, 625 penicillin-susceptible 2007 isolates were also tested. Susceptibility was determined by agar dilution using Mueller-Hinton agar supplemented with 5% sheep blood. Penicillin-susceptible strains were susceptible to amoxicillin, cefotaxime and ceftriaxone, 99.8% to cefpodoxime and 99.5% to cefdinir, and were inhibited by 0.12 microg/ml of cefditoren and 4 microg/ml of cefixime. Penicillin-intermediate strains were susceptible to cefotaxime and ceftriaxone, with <50% susceptibility to cefdinir and cefpodoxime. The MIC(50) and MIC(90) values of cefditoren were 0.25 microg/ml and 0.5 microg/ml, respectively, whereas cefixime exhibited only marginal activity (MIC(90)=16 microg/ml). Penicillin-resistant strains were resistant to cefdinir and cefpodoxime, with 74.8% and 94.1% susceptibility to cefotaxime and ceftriaxone, respectively. Cefditoren MIC(50)/MIC(90) (0.5/1 microg/ml) were lower than cefotaxime and ceftriaxone. Among amoxicillin non-susceptible strains, susceptibility to cefdinir and cefpodoxime was <10%, and susceptibility to cefotaxime decreased from 87.9% in the intermediate category to 63.0% in the resistant group. Cefditoren MIC(50)/MIC(90) (0.5/1 microg/ml) were lower than cefotaxime. In conclusion, the activity of cefixime, cefdinir and cefpodoxime was highly affected by penicillin/amoxicillin non-susceptibility, while parenteral third-generation cephalosporins exhibited higher intrinsic activity (MIC(90)=1 microg/ml for penicillin-resistant and 2 microg/ml for amoxicillin-resistant strains). Cefditoren exhibited one-dilution lower MIC(90) values for these strains, even against those of the most troublesome serotypes. PMID:17943330

Fenoll, A; Giménez, M J; Robledo, O; Aguilar, L; Tarragó, D; Granizo, J J; Martín-Herrero, J E

2008-01-01

22

Structural studies on copper(II) complex containing (Z)-2-(2-Aminothiazol-4-yl)- N-(2-hydroxyethyl)-2-(hydroxyimino) acetamide, A model compound for a cephalosporin antibiotic cefdinir  

Microsoft Academic Search

(Z)-2-(2-aminothiazol-4-yl)-N-(2-hydroxyethyl)-2-(hydroxyimino)acetamide (HL) has been employed as a model compound for an orally active cephalosporin antibiotic, Cefdinir (CFDN). A binuclear copper(II) complex Cu2L4 (1) has been obtained from an aqueous solution containing CuCl2 and HL, and its structure determined by means of X-ray crystallography: monoclinic, P2\\/c, a = 11.954(3) A?, b = 10.661(3) A?, c = 16.969(7) A?, ? = 108.13(3)°,

Shuhei Deguchi; Yayoi Shihahara; Marie T. Mooney; Kyoko Yamamoto; Toshiji Tada; Mamoru Fujioka; Yoshihiko Okamoto; Tsutomu Yasuda; Shinnichiro Suzuki

1997-01-01

23

Analysis of Salmonella enterica with reduced susceptibility to the third-generation cephalosporin ceftriaxone isolated from U.S. cattle during 2000-2004.  

PubMed

Over the past decade enteric bacteria in Europe, Africa, and Asia have become increasingly resistant to cephalosporin antimicrobial agents. This is largely due to the spread of genes encoding extended-spectrum beta-lactamase (ESBL) enzymes that can inactivate many cephalosporins. Recently, these resistance mechanisms have been identified in Salmonella isolated from humans in the United States. Due to the potential for transmission of resistant bacteria to humans via food animals, Salmonella animal isolates were monitored for ESBL production. During 2000-2004, Salmonella cattle slaughter isolates (n = 3,984) were tested, and 97 (2.4%) of these were found to have decreased susceptibility (minimum inhibitory concentration [MIC] >32 microg/ml) to the third-generation cephalosporin ceftriaxone. The majority of these were serotypes Newport (58) and Agona (14), some of which were genetically indistinguishable by pulsed field gel electrophoresis (PFGE) analysis. None of the isolates had an ESBL phenotype; all were susceptible to the fourth-generation cephalosporins cefepime and cefquinome. PCR and sequence analysis for resistance genes detected the bla(CMY-2) gene in 93 isolates and the bla(TEM-1) gene in 12 isolates; however, neither gene encodes an ESBL. These data indicate that bovine Salmonella isolates from the United States with decreased susceptibility or resistance to ceftriaxone do not exhibit an ESBL phenotype and most contain the bla(CMY-2) gene. PMID:19025468

Frye, Jonathan G; Fedorka-Cray, Paula J; Jackson, Charlene R; Rose, Markus

2008-12-01

24

Immunotoxicity of cephalosporins in mice.  

PubMed

This study was performed in female B6C3F1 mice to confirm previously observed effects of selected cephalosporin antibiotics on nonspecific immunity, and to determine possible effects on specific acquired immunity and host resistance. Mice were treated intravenously with DQ-2556, ceftizoxime or ceftezole at 800 mg/kg/day for 3, 5, or 7 consecutive days. All three compounds increased total serum IgM levels from day 3, but had no effects on total serum IgG levels and the thymus weight. All three cephalosporin antibiotics caused a slight increase in spleen weight and splenic germinal centers were enlarged after 5- or 7-day treatments. Antibody responses to type III pneumococcal polysaccharide (S3), a T-cell-independent immunogen, and sheep red blood cells (SRBC), a T-cell-dependent immunogen, were slightly decreased after 5-day dosings with each compound, and reached significance in DQ-2556 (response to S3) and ceftizoxime (response to S3 and SRBC). None of the tested cephalosporin antibiotics altered delayed-type hypersensitivity to oxazolone or host resistance to Plasmodium yoelii, indicating that the antibiotic-treated mice retained the capacity to mount a multicomponent and sustained protective immune response. These data suggest that although cephalosporins may cause polyclonal expansion of B cells with associated increases in total serum IgM, they do not affect the tested measures of cell-mediated immunity or host resistance. The decreased IgM antibody responses to S3 and SRBC are associated with but not known to be causally related to the concurrent IgM hypergammaglobulinemia. PMID:8325130

Furuhama, K; Benson, R W; Knowles, B J; Roberts, D W

1993-01-01

25

Diagnosis and management of immediate hypersensitivity reactions to cephalosporins.  

PubMed

Cephalosporins can cause a range of hypersensitivity reactions, including IgE-mediated, immediate reactions. Cephalosporin allergy has been reported with use of a specific cephalosporin, as a cross-reaction between different cephalosporins or as a cross-reaction to other ?-lactam antibiotics. Unlike penicillins, the exact allergenic determinants of cephalosporins are less well understood and thus, standardized diagnostic skin testing is not available. Nevertheless, skin testing with diluted solutions of cephalosporins can be valuable in confirming IgE-mediated hypersensitivity reactions. In vitro tests are in development using recent technological advances and can be used as complementary tests. However, they are not commonly used because of their reduced sensitivity and limited availability. In selected cases of inconclusive results in both skin tests and IgE assays, a graded challenge or induction of drug tolerance with the implicated cephalosporin should be performed. PMID:25374747

Kim, Min-Hye; Lee, Jong-Myung

2014-11-01

26

Diagnosis and Management of Immediate Hypersensitivity Reactions to Cephalosporins  

PubMed Central

Cephalosporins can cause a range of hypersensitivity reactions, including IgE-mediated, immediate reactions. Cephalosporin allergy has been reported with use of a specific cephalosporin, as a cross-reaction between different cephalosporins or as a cross-reaction to other ?-lactam antibiotics. Unlike penicillins, the exact allergenic determinants of cephalosporins are less well understood and thus, standardized diagnostic skin testing is not available. Nevertheless, skin testing with diluted solutions of cephalosporins can be valuable in confirming IgE-mediated hypersensitivity reactions. In vitro tests are in development using recent technological advances and can be used as complementary tests. However, they are not commonly used because of their reduced sensitivity and limited availability. In selected cases of inconclusive results in both skin tests and IgE assays, a graded challenge or induction of drug tolerance with the implicated cephalosporin should be performed. PMID:25374747

Kim, Min-Hye

2014-01-01

27

Antibiotic sensitivity profiles determined with an Escherichia coli gene knockout collection: generating an antibiotic bar code.  

PubMed

We have defined a sensitivity profile for 22 antibiotics by extending previous work testing the entire KEIO collection of close to 4,000 single-gene knockouts in Escherichia coli for increased susceptibility to 1 of 14 different antibiotics (ciprofloxacin, rifampin [rifampicin], vancomycin, ampicillin, sulfamethoxazole, gentamicin, metronidazole, streptomycin, fusidic acid, tetracycline, chloramphenicol, nitrofurantoin, erythromycin, and triclosan). We screened one or more subinhibitory concentrations of each antibiotic, generating more than 80,000 data points and allowing a reduction of the entire collection to a set of 283 strains that display significantly increased sensitivity to at least one of the antibiotics. We used this reduced set of strains to determine a profile for eight additional antibiotics (spectinomycin, cephradine, aztreonem, colistin, neomycin, enoxacin, tobramycin, and cefoxitin). The profiles for the 22 antibiotics represent a growing catalog of sensitivity fingerprints that can be separated into two components, multidrug-resistant mutants and those mutants that confer relatively specific sensitivity to the antibiotic or type of antibiotic tested. The latter group can be represented by a set of 20 to 60 strains that can be used for the rapid typing of antibiotics by generating a virtual bar code readout of the specific sensitivities. Taken together, these data reveal the complexity of intrinsic resistance and provide additional targets for the design of codrugs (or combinations of drugs) that potentiate existing antibiotics. PMID:20065048

Liu, Anne; Tran, Lillian; Becket, Elinne; Lee, Kim; Chinn, Laney; Park, Eunice; Tran, Katherine; Miller, Jeffrey H

2010-04-01

28

Antibiotic consumption and antibiotic stewardship in Swedish hospitals  

PubMed Central

Background The aim of this paper was to describe and analyze the effect of antibiotic policy changes on antibiotic consumption in Swedish hospitals and to review antibiotic stewardship in Swedish hospitals. Results The main findings were: 1) Antibiotic consumption has significantly increased in Swedish hospitals over the last decade. The consumption of cephalosporins has decreased, whereas that of most other drugs including piperacillin-tazobactam, carbapenems, and penicillinase-sensitive and -resistant penicillins has increased and replaced cephalosporins. 2) Invasive infections caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae have increased, but the proportion of pathogens resistant to third-generation cephalosporins causing invasive infections is still very low in a European and international perspective. Furthermore, the following gaps in knowledge were identified: 1) lack of national, regional, and local data on the incidence of antibiotic resistance among bacteria causing hospital-acquired infections e.g. bloodstream infections and hospital-acquired pneumonia—data on which standard treatment guidelines should be based; 2) lack of data on the incidence of Clostridium difficile infections and the effect of change of antibiotic policies on the incidence of C. difficile infections and infections caused by antibiotic-resistant pathogens; and 3) lack of prospective surveillance programs regarding appropriate antibiotic treatment, including selection of optimal antimicrobial drug regimens, dosage, duration of therapy, and adverse ecological effects such as increases in C. difficile infections and emergence of antibiotic-resistant pathogens. Conclusions Evidence-based actions to improve antibiotic use and to slow down the problem of antibiotic resistance need to be strengthened. The effect of such actions should be analyzed, and standard treatment guidelines should be continuously updated at national, regional, and local levels. PMID:24724823

Skoog, Gunilla; Ternhag, Anders; Giske, Christian G.

2014-01-01

29

Occurrence and Genetic Characteristics of Third-Generation Cephalosporin-Resistant Escherichia coli in Swiss Retail Meat.  

PubMed

Prevalence and genetic relatedness were determined for third-generation cephalosporin-resistant Escherichia coli (3GC-R-Ec) detected in Swiss beef, veal, pork, and poultry retail meat. Samples from meat-packing plants (MPPs) processing 70% of the slaughtered animals in Switzerland were purchased at different intervals between April and June 2013 and analyzed. Sixty-nine 3GC-R-Ec isolates were obtained and characterized by microarray, PCR/DNA sequencing, Multi Locus Sequence Typing (MLST), and plasmid replicon typing. Plasmids of selected strains were transformed by electroporation into E. coli TOP10 cells and analyzed by plasmid MLST. The prevalence of 3GC-R-Ec was 73.3% in chicken and 2% in beef meat. No 3GC-R-Ec were found in pork and veal. Overall, the blaCTX-M-1 (79.4%), blaCMY-2 (17.6%), blaCMY-4 (1.5%), and blaSHV-12 (1.5%) ?-lactamase genes were detected, as well as other genes conferring resistance to chloramphenicol (cmlA1-like), sulfonamides (sul), tetracycline (tet), and trimethoprim (dfrA). The 3GC-R-Ec from chicken meat often harbored virulence genes associated with avian pathogens. Plasmid incompatibility (Inc) groups IncI1, IncFIB, IncFII, and IncB/O were the most frequent. A high rate of clonality (e.g., ST1304, ST38, and ST93) among isolates from the same MPPs suggests that strains persist at the plant and spread to meat at the carcass-processing stage. Additionally, the presence of the blaCTX-M-1 gene on an IncI1 plasmid sequence type 3 (IncI1/pST3) in genetically diverse strains indicates interstrain spread of an epidemic plasmid. The blaCMY-2 and blaCMY-4 genes were located on IncB/O plasmids. This study represents the first comprehensive assessment of 3GC-R-Ec in meat in Switzerland. It demonstrates the need for monitoring contaminants and for the adaptation of the Hazard Analysis and Critical Control Point concept to avoid the spread of multidrug-resistant bacteria through the food chain. PMID:24773305

Vogt, Debora; Overesch, Gudrun; Endimiani, Andrea; Collaud, Alexandra; Thomann, Andreas; Perreten, Vincent

2014-10-01

30

In vitro Activity of Two New Oral Cephalosporins, Cefixime and Cefdinir (CI 983), on Human Peripheral Mononuclear and Polymorphonuclear Leukocyte Functions  

Microsoft Academic Search

The in vitro effects of cefixime and cefdinir (CI 983), two so-called third-generation oral cephalosporin derivatives, on human polymorphonuclear and mononuclear phagocyte functions (random migration and chemotaxis, specific and nonspecific phagocytosis, nitroblue tetrazolium reduction, superoxide production, microbicidal activity) were studied. Neither antibiotic, in the range of its attainable therapeutic concentration, exhibited any toxic effect on random migration, chemotaxis, metabolic activation

A. Fietta; C. Merlini; Gialdroni Grassi

1994-01-01

31

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

PubMed Central

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??g/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 in in vitro condition. This study suggested that curcumin-1 in combination with antibiotics could lead to the development of new combination of antibiotics against diarrhea causing bacteria. PMID:24949457

Sasidharan, Nishanth Kumar; Sreekala, Sreerag Ravikumar; Jacob, Jubi; Nambisan, Bala

2014-01-01

32

High Rates of Multiple Antibiotic Resistance in Streptococcus pneumoniae From Healthy Children Living in Isolated Rural Communities: Association With Cephalosporin Use and Intrafamilial Transmission  

Microsoft Academic Search

ABSTRACT. Objective. Streptococcus pneumoniae is one of the most clinically significant pathogens with emerging antibiotic resistance. We performed a surveil- lance study in isolated rural populations of healthy chil- dren to estimate the prevalence of pneumococcal resis- tance and to contrast factors that predict pneumococcal carriage with those that specifically predict resistant pneumococcal carriage. Methods. The study was conducted in

Matthew H. Samore; Michael K. Magill; Stephen C. Alder; Elena Severina; Leonie Morrison-de Boer; J. Lynn Lyon; MPH Karen Carroll; Joyce Leary; Mary Bishop Stone; MPH James Reading; Alexander Tomasz; Merle A. Sande

33

Antibiotics  

MedlinePLUS

Antibiotics are powerful medicines that fight bacterial infections. Used properly, antibiotics can save lives. They either kill bacteria or ... natural defenses can usually take it from there. Antibiotics do not fight infections caused by viruses, such ...

34

Recurrent Klebsiella pneumoniae mycotic aneurysm in a diabetic patient and emergence of an extended-spectrum beta-lactamase (CTX-M-24)-containing Klebsiella pneumoniae strain after prolonged treatment with first-generation cephalosporins for mycotic aneurysm.  

PubMed

A 68-year-old diabetic woman suffered from mycotic aneurysm due to Klebsiella pneumoniae over her abdominal aorta; she received surgical intervention, followed by treatment with first-generation cephalosporins for 6 months. She was hospitalized again 11 months later because of another episode of mycotic aneurysm caused by K. pneumoniae on her thoracic aorta. Fingerprinting generated by pulsed-field gel electrophoresis and infrequent-restriction-site polymerase indicated K. pneumoniae isolates of the identical clonal strain were responsible for these two mycotic-aneurysm episodes. Unfortunately, nosocomial pneumonia developed at the second hospitalization; blood and purposefully sampled feces specimen cultures both grew CTX-M-24-producing K. pneumoniae, which were of the same strain and genetically nonrelated to the K. pneumoniae strain causing mycotic aneurysms earlier. This is the first report on infection due to CTX-M-24-producing K. pneumoniae. It is unclear whether the prolonged use of first-generation cephalosporins in this case selected a strain of enteric organism possessing the ESBL in question, which was capable of passing this ESBL plasmid to the K. pneumoniae strain causing the nosocomial infection. This report suggests that further observation is needed before one can draw a conclusion on the possibility of the selection of ESBL enteric organism by extensive exposure to first-generation cephalosporins. PMID:15650383

Lee, Chen-Hsiang; Su, Lin-Hui; Chia, Ju-Hsin; Tsai, Kuei-Ton; Wu, Tsu-Lan; Liu, Jien-Wei

2004-01-01

35

Theoretical aspects of cephalosporin isomerism  

SciTech Connect

The {triangle}{sup 3} double bond of cephalosporins isomerizes to the {triangle}{sup 2} position, resulting in biological inactivation of these antibiotics. This phenomenon occurs slowly in the case of cephalosporanic acids, but is rapid when the 4-carboxylate moiety is esterified or otherwise derivatized, leading to an equilibrium between the {triangle}{sup 2} and {triangle}{sup 3} forms. A theoretical study of this isomerization is described in the framework of two semiempirical all-valence electron molecular orbital (MO) approximations, namely MNDO and AMI. Specifically, the methyl ester and free carboxylate derivatives of both the {triangle}{sup 3} and {triangle}{sup 2} isomers of 7-phenylacetamidocephalosporin were studied. The results obtained indicated that the {triangle}{sup 3} derivatives were thermodynamically more stable than were the {triangle}{sup 2} isomers both in the case of the free acids and methyl esters. These data are consistent with experimental findings and suggest that the more rapid isomerization demonstrated in the case of the esters is due primarily to kinetic rather than to thermodynamic factors. Examination of the calculated molecular structures lend support to various theories that correlate the inactivity of the {triangle}{sup 2} isomers with spatial considerations and the degree of {beta}-lactam amide resonance.

Pop, E.; Brewster, M.E.; Bodor, N. (Pharmatec, Inc., Alachua, FL (USA) Univ. of Florida, Gainesville (USA)); Kaminski, J.J. (Schering-Plough Corp., Bloomfield, NJ (USA))

1989-01-01

36

In Vitro activity of cepfodoxime in comparison with other oral ?-lactam antibiotics  

Microsoft Academic Search

Summary The aim of our study was to re-evaluate thein vitro activity of cefpodoxime in comparison with other oral ß-lactam antibiotics against bacteria causing respiratory tract infections. The study drugs were cefpodoxime, cefaclor, cefixime, cefuroxime, cefetamet, cefprozil, and the combination of amoxicillin and clavulanic acid (= augmentin). In addition, cefotaxime as the standard agent of parenteral third generation cephalosporins was

F. H. Kayser

1994-01-01

37

A Homologue of the Aspergillus velvet Gene Regulates both Cephalosporin C Biosynthesis and Hyphal Fragmentation in Acremonium chrysogenum?  

PubMed Central

The Aspergillus nidulans velvet (veA) gene encodes a global regulator of gene expression controlling sexual development as well as secondary metabolism. We have identified the veA homologue AcveA from Acremonium chrysogenum, the major producer of the ?-lactam antibiotic cephalosporin C. Two different disruption strains as well as the corresponding complements were generated as a prelude to detailed functional analysis. Northern hybridization and quantitative real-time PCR clearly indicate that the nucleus-localized AcVEA polypeptide controls the transcriptional expression of six cephalosporin C biosynthesis genes. The most drastic reduction in expression is seen for cefEF, encoding the deacetoxycephalosporine/deacetylcephalosporine synthetase. After 120 h of growth, the cefEF transcript level is below 15% in both disruption strains compared to the wild type. These transcriptional expression data are consistent with results from a comparative and time-dependent high-performance liquid chromatography analysis of cephalosporin C production. Compared to the recipient, both disruption strains have a cephalosporin C titer that is reduced by 80%. In addition to its role in cephalosporin C biosynthesis, AcveA is involved in the developmentally dependent hyphal fragmentation. In both disruption strains, hyphal fragmentation is already observed after 48 h of growth, whereas in the recipient strain, arthrospores are not even detected before 96 h of growth. Finally, the two mutant strains show hyperbranching of hyphal tips on osmotically nonstabilized media. Our findings will be significant for biotechnical processes that require a defined stage of cellular differentiation for optimal production of secondary metabolites. PMID:17400783

Dreyer, Jacqueline; Eichhorn, Heiko; Friedlin, Ernst; Kurnsteiner, Hubert; Kuck, Ulrich

2007-01-01

38

Quality of perioperative antibiotic administration by French anaesthetists.  

PubMed

Antibiotics are the most prescribed drugs in hospitals in France and approximately one-third of prescriptions are for antimicrobial prophylaxis. Although the principles of prophylaxis have been defined over the years, there is still widespread misuse of antimicrobials for that purpose. The aim of this survey was to determine whether prescription of prophylactic antibiotics by French anaesthetists complies with the French Guidelines on Surgical Antibiotic Prophylaxis. Information was sought concerning the agent(s) recommended, the timing of the first dose and the duration of prescription. A total of 1473 French anaesthetists was studied. For the great majority (93%), the first antibiotic dose is administered at time of induction of anaesthesia, as recommended by the guidelines. First- and second-generation cephalosporins are frequently selected, as well as co-amoxiclav. In contrast to the guidelines, third-generation cephalosporins (3GCs) are widely prescribed in digestive and urological surgery and quinolones in urological surgery. Duration of prescription is limited to 48 h by most anaesthetists (94%), however there is a strong tendency to prescribe prophylaxis for longer periods in the immunocompromised and patients undergoing major surgery. This survey indicates discrepancies between the French Guidelines on Surgical Antibiotic Prophylaxis and the current practice of French anaesthetists. Major concerns are the use of antibiotics such as 3GCs or fluoroquinolones and prescription for periods exceeding 48 h. In conclusion, compliance with guidelines for prophylactic antimicrobial administration should be more strict in surgical patients. PMID:9777521

Martin, C; Pourriat, J L

1998-09-01

39

[Antibiotic prophylaxis in visceral and urologic pædiatric surgery].  

PubMed

Surgical site infections are the leading cause of perioperative morbidity and mortality as well as increased costs following surgery. Among preventive measures, antibiotic prophylaxis significantly decreases this risk. Adult guidelines have recently been published. Specific pædiatric data are scarce, but adult recommendations can be used by extrapolation except for the neonates. For procedures that may warrant antimicrobial prophylaxis, agents of choice are first-generation cephalosporins who are not currently used in curative treatment, like cefazolin, with an appropriate dosing. A single perioperative dose of antibiotics is often sufficient. Continuation for more than 24 hours is rarely advised. PMID:24360304

Haas, H; Schneider, G; Moulin, F

2013-11-01

40

Analysis of cephalosporins by hydrophilic interaction chromatography  

Microsoft Academic Search

A simple hydrophilic interaction chromatography (HILIC) method was developed to analyze seven cephalosporins. These seven cephalosporins could be separated well on the Click ?-CD column and Atlantis HILIC Silica column. The effects of buffer concentration and pH on the retention under HILIC mode were studied. Except cefepime hydrochloride (4), the retention of other six cephalosporins increased with increasing buffer concentration,

Qiaoxia Liu; Lingyan Xu; Yanxiong Ke; Yu Jin; Feifang Zhang; Xinmiao Liang

41

Lysine epsilon-aminotransferase, the initial enzyme of cephalosporin biosynthesis in actinomycetes.  

PubMed

Streptomyces clavuligerus, Streptomyces lipmanii and Nocardia (formerly Streptomyces) lactamdurans are Gram-positive mycelial bacteria that produce medically important beta-lactam antibiotics (penicillins and cephalosporins including cephamycins) that are synthesized through a series of reactions starting from lysine, cysteine and valine. L-lysine epsilon-aminotransferase (LAT) is the initial enzyme in the two-step conversion of L-lysine to L-alpha-aminoadipic acid, a specific precursor of all penicillins and cephalosporins. Whereas S. clavuligerus uses LAT for cephalosporin production, it uses the cadaverine pathway for catabolism when lysine is the nitrogen source for growth. Although the cadaverine path is present in all examined streptomycetes, the LAT pathway appears to exist only in beta-lactam-producing strains. Genetically increasing the level of LAT enhances the production of cephamycin. LAT is the key rate-limiting enzyme in cephalosporin biosynthesis in S. clavuligerus strain NRRL 3585. This review will summarize information on this important enzyme. PMID:11540168

Rius, N; Demain, A L

1997-04-01

42

Draft Genome Sequence of Escherichia coli Strain VKPM B-10182, Producing the Enzyme for Synthesis of Cephalosporin Acids  

PubMed Central

Escherichia coli strain VKPM B-10182, obtained by chemical mutagenesis from E. coli strain ATCC 9637, produces cephalosporin acid synthetase employed in the synthesis of ?-lactam antibiotics, such as cefazolin. The draft genome sequence of strain VKPM B-10182 revealed 32 indels and 1,780 point mutations that might account for the improvement in antibiotic synthesis that we observed. PMID:25414512

Mardanov, Andrey V.; Eldarov, Mikhail A.; Sklyarenko, Anna V.; Dumina, Maria V.; Beletsky, Alexey V.; Yarotsky, Sergey V.

2014-01-01

43

In vitro Activity of Cefdinir (FK 482, PD 134393, CI983): A New Orally Active Cephalosporin  

Microsoft Academic Search

Cefdinir is a new orally active cephalosporin which is undergoing in vitro and in vivo evaluations. Using the standard agar dilution method we compared the in vitro activity of this drug with other (3-lactam antibiotics against clinical isolates or Ente-robacteriaceae (625 strains), Pseudomonas aeruginosa (68 strains), Xanthomonas maltophilia (36 strains), Acinetobacter (52 strains), Aeromonas hydrophilia (47 strains), staphylococci (364 strains)

Hussain Qadri; Yoshio Ueno; Hishama Saldin; Burke A. Cunha

1993-01-01

44

Understanding the patterns of antibiotic susceptibility of bacteria causing urinary tract infection in West Bengal, India  

PubMed Central

Urinary tract infection (UTI) is one of the most common infectious diseases at the community level. In order to assess the adequacy of empirical therapy, the susceptibility of antibiotics and resistance pattern of bacteria responsible for UTI in West Bengal, India, were evaluated throughout the period of 2008–2013. The infection reports belonging to all age groups and both sexes were considered. Escherichia coli was the most abundant uropathogen with a prevalence rate of 67.1%, followed by Klebsiella spp. (22%) and Pseudomonas spp. (6%). Penicillin was least effective against UTI-causing E. coli and maximum susceptibility was recorded for the drugs belonging to fourth generation cephalosporins. Other abundant uropathogens, Klebsiella spp., were maximally resistant to broad-spectrum penicillin, followed by aminoglycosides and third generation cephalosporin. The antibiotic resistance pattern of two principal UTI pathogens, E. coli and Klebsiella spp. in West Bengal, appears in general to be similar to that found in other parts of the Globe. Higher than 50% resistance were observed for broad-spectrum penicillin. Fourth generation cephalosporin and macrolides seems to be the choice of drug in treating UTIs in Eastern India. Furthermore, improved maintenance of infection incident logs is needed in Eastern Indian hospitals in order to facilitate regular surveillance of the occurrence of antibiotic resistance patterns, since such levels continue to change. PMID:25278932

Saha, Sunayana; Nayak, Sridhara; Bhattacharyya, Indrani; Saha, Suman; Mandal, Amit K.; Chakraborty, Subhanil; Bhattacharyya, Rabindranath; Chakraborty, Ranadhir; Franco, Octavio L.; Mandal, Santi M.; Basak, Amit

2014-01-01

45

The role of newer antibiotics in gastroenterology.  

PubMed

The past decade has seen the introduction of a number of new potent antimicrobial agents, including broad-spectrum beta-lactam compounds such as the ureidopenicillins, third-generation cephalosporins, carbapenems, and monobactams; combinations of penicillins with inhibitors of beta-lactamase; and the quinolones. Most of these agents have excellent activity against enteric gram-negative rods and some are active against anaerobic organisms, the two bacterial groups most likely to be encountered in gastrointestinal infections. Despite the potency and wide spectrum of many of these new agents, there are currently relatively few clinical situations in which any of the newer antimicrobials are the first-line agents for therapy or prophylaxis of gastrointestinal diseases. Reluctance to use these agents as first-line therapy is based on concerns about the selection and spread of resistant organisms, superinfection syndromes, and the high cost of many of the newer agents. Specific clinical settings in which these agents may be given preference are as follows: 1. use of a third-generation cephalosporin (cefotaxime or ceftriaxone) in the treatment of spontaneous bacterial peritonitis. 2. use of broad-spectrum beta-lactam compounds to provide gram-negative coverage in patients who should not receive aminoglycosides 3. use of a third-generation cephalosporin (ceftriaxone) in the treatment of central nervous system relapses of Whipple's disease 4. use of quinolones for the empiric treatment of suspected bacterial diarrhea in patients sufficiently ill to require empiric initiation of antibiotics. 5. use of quinolones for the treatment of chronic carriers of Salmonella typhi 6. use of norfloxacin for prophylaxis against SBP. As further experience with these new antimicrobial agents is obtained and as more bacteria develop resistance to current first-line agents, there can be little doubt that these new antibiotics will play an increasing role in the prevention and treatment of gastrointestinal disease. PMID:1516960

Li, E; Stanley, S L

1992-09-01

46

Quinolone and Cephalosporin Resistance in Enteric Fever  

PubMed Central

Enteric fever is a major public health problem in developing countries. Ciprofloxacin resistance has now become a norm in the Indian subcontinent. Novel molecular substitutions may become frequent in future owing to selective pressures exerted by the irrational use of ciprofloxacin in human and veterinary therapeutics, in a population endemic with nalidixic acid-resistant strains. The therapeutics of ciprofloxacin-resistant enteric fever narrows down to third- and fourth-generation cephalosporins, azithromycin, tigecycline and penems. The first-line antimicrobials ampicillin, chloramphenicol and co-trimoxazole need to be rolled back. Antimicrobial surveillance coupled with molecular analysis of fluoroquinolone resistance is warranted for reconfirming novel and established molecular patterns for therapeutic reappraisal and for novel-drug targets. This review explores the antimicrobial resistance and its molecular mechanisms, as well as novel drugs in the therapy of enteric fever. PMID:20927288

Capoor, Malini Rajinder; Nair, Deepthi

2010-01-01

47

Cephalosporin and Aminoglycoside Concentrations in Peritoneal Capsular Fluid in Rabbits  

PubMed Central

To study the penetration of antibiotics into peritoneal tissue fluid, a subcutaneous tissue capsule model was modified by implanting multiple, perforated spherical capsules in the peritoneal cavity of rabbits. Capsules became vascularized, encased in connective tissue, and filled with fluid having a mean protein concentration of 3.6 g/100 ml. Capsular fluid was obtained by percutaneous needle aspiration and assayed for antibiotic by the disk plate bioassay technique. Cephalosporins were administered intramuscularly at a dose of 30 mg/kg. Mean peak concentrations of cephaloridine and cefazolin were significantly higher than cephalothin and cephapirin in capsular fluids, but the percent penetration (ratio of capsular mean peak to serum mean peak) ranged from 8.7 to 16.9% and was not significantly different among the cephalosporins. At 24 h the capsular concentration of cefazolin was significantly greater than for the other cephalosporins (P < 0.001). Lower rabbit serum protein binding observed at high in vivo concentrations may have enabled cefazolin to penetrate capsular fluid, but in vitro protein binding studies did not confirm a decrease in serum protein binding at high concentrations within the clinical range. Kanamycin and amikacin showed comparable capsular fluid peak concentrations as did gentamicin and tobramycin. The percent penetration ranged from 15.2 to 34.5% for the aminoglycosides. The only statistical difference was that amikacin penetration was significantly higher than that for tobramycin. Mean capsular concentrations of amikacin, cefazolin, and cephaloridine compared most favorably with the minimum inhibitory concentration of gram-negative bacilli at the dosages used in this study. Images PMID:1008548

Gerding, Dale N.; Hall, Wendell H.; Schierl, Elizabeth A.; Manion, Robert E.

1976-01-01

48

Analysis of cephalosporins by hydrophilic interaction chromatography.  

PubMed

A simple hydrophilic interaction chromatography (HILIC) method was developed to analyze seven cephalosporins. These seven cephalosporins could be separated well on the Click ?-CD column and Atlantis HILIC Silica column. The effects of buffer concentration and pH on the retention under HILIC mode were studied. Except cefepime hydrochloride (4), the retention of other six cephalosporins increased with increasing buffer concentration, while decreased with increasing pH. Different separation selectivities could be observed on the Click ?-CD column and Atlantis HILIC Silica column, and changing pH also resulted in the changing of separation selectivity. The separations of cephalosporins by HILIC and reversed-phase high performance liquid chromatography (RP-HPLC) were compared, and the two separation modes had good orthogonality. In addition, cefotaxime sodium (1) and its degradation were separated well on the Click ?-CD column, which indicated that the Click ?-CD column by HILIC can be used for studying the stability of cephalosporins. PMID:21035295

Liu, Qiaoxia; Xu, Lingyan; Ke, Yanxiong; Jin, Yu; Zhang, Feifang; Liang, Xinmiao

2011-02-20

49

Activity of vancomycin, teicoplanin and cephalosporins against penicillin-susceptible and penicillin-intermediate Streptococcus pneumoniae  

PubMed Central

Objective: To report in vitro susceptibilities of penicillin-susceptible and penicillin-intermediate Streptococcus pneumoniae isolates to cephalosporins, vancomycin and teicoplanin. Design: Minimal inhibitory concentrations (mic) were determined according to National Committee for Clinical Laboratory Standards guidelines for 17 penicillin-susceptible isolates (mic 0.06 mg/L or less) and 16 isolates showing intermediate susceptibility to penicillin (mic 0.12 to 1.0 mg/L). Setting: Tertiary care university centre. Main Results: Comparison of the mic90 values with those of other antibiotics tested demonstrated that ceftriaxone, cefotaxime and teicoplanin were the most active agents against penicillin-susceptible strains. However, teicoplanin had the lowest mic and was superior to other agents against strains with intermediate penicillin susceptibility. The mics of all cephalosporins increased in concordance with the mic of penicillin. Conclusion: Isolates demonstrating intermediate susceptibility or resistance to penicillin should be routinely evaluated for susceptibility to clinically important cephalosporins. PMID:22416208

Loo, Vivian G; Lavallee, Jocelyne; McAlear, Diane; Robson, Hugh G

1995-01-01

50

In Vitro Selection of Neisseria gonorrhoeae Mutants with Elevated MIC Values and Increased Resistance to Cephalosporins.  

PubMed

Strains of Neisseria gonorrhoeae with mosaic penA genes bearing novel point mutations in penA have been isolated from ceftriaxone treatment failures. Such isolates exhibit significantly higher MIC values to third-generation cephalosporins. Here we report the in vitro isolation of two mutants with elevated MICs to cephalosporins. The first possesses a point mutation in the transpeptidase region of the mosaic penA gene, and the second contains an insertion mutation in pilQ. PMID:25199775

Johnson, Steven R; Grad, Yonatan; Ganakammal, Satishkumar Ranganathan; Burroughs, Mark; Frace, Mike; Lipsitch, Marc; Weil, Ryan; Trees, David

2014-11-01

51

Therapeutic activities of antibiotics in listeriosis  

Microsoft Academic Search

Summary In vitro practically all common antibiotics except cephalosporins are active against nearly all natural isolates ofListeria monocytogenes; the therapeutic efficacy of antibiotic treatment is, however, rather limited, since up to 30% listeriosis patients will succumb to this infection. At least one reason for this lowin vivo efficiency is the intracellular habitat ofL. monocytogenes. In animal experiments ampicillin or amoxicillin,

H. Hof

1991-01-01

52

Synthesis of cephalosporin-3'-diazeniumdiolates: biofilm dispersing NO-donor prodrugs activated by ?-lactamase.  

PubMed

Use of biofilm dispersing NO-donor compounds in combination with antibiotics has emerged as a promising new strategy for treating drug-resistant bacterial biofilm infections. This paper details the synthesis and preliminary evaluation of six cephalosporin-3'-diazeniumdiolates as biofilm-targeted NO-donor prodrugs. Each of the compounds is shown to selectively release NO following reaction with the bacteria-specific enzyme ?-lactamase and to trigger dispersion of Pseudomonas aeruginosa biofilms in vitro. PMID:23603842

Yepuri, Nageshwar Rao; Barraud, Nicolas; Mohammadi, Nasim Shah; Kardak, Bharat G; Kjelleberg, Staffan; Rice, Scott A; Kelso, Michael J

2013-05-25

53

A novel cephalosporin deacetylating acetyl xylan esterase from Bacillus subtilis with high activity toward cephalosporin C and 7-aminocephalosporanic acid.  

PubMed

A cephalosporin deacetylating acetyl xylan esterase was cloned from the genomic DNA of Bacillus subtilis CICC 20034 and functionally expressed in Escherichia coli. Its gene contained an open reading frame of 957 bp encoding 318 amino acids with a calculated mass of 35,607 Da, and it displayed significant identity to acetyl xylan esterases from Bacillus sp. 916, B. subtilis 168, and Bacillus pumilus Cect5072. The enzyme was a native homohexamer but a trimer under the condition of 1% sodium dodecyl sulfate (SDS); both forms were active and could transit to each other by incubating in or removing SDS. The enzyme belongs to carbohydrate esterase family 7 and had a double specificity on both the acetylated oligosaccharide and cephalosporin C (CPC) and 7-aminocephalosporanic acid (7-ACA). The activity of this purified enzyme toward CPC and 7-ACA was highest among all the acetyl xylan esterase from CE family 7, which were 484 and 888 U/mg, respectively, and endowed itself with great industrial interest on semi-synthetic ?-lactam antibiotics. The optimum pH of the purified enzyme was 8.0, and the optimum temperature was 50 °C, and the enzyme had high thermal stability, broad range of pH tolerance, and extremely organic solvent tolerance. PMID:23828600

Tian, Qianqian; Song, Ping; Jiang, Ling; Li, Shuang; Huang, He

2014-03-01

54

Antibiotic consumption and its influence on the resistance in Enterobacteriaceae  

PubMed Central

Background Increasing bacterial resistance to antibiotics is one of the most serious problems in current medicine. An important factor contributing to the growing prevalence of multiresistant bacteria is application of antibiotics. This study aimed at analyzing the development of resistance of Enterobacteriaceae to selected beta-lactam, fluoroquinolone and aminoglycoside antibiotics in the University Hospital Olomouc and assessing the effect of selection pressure of these antibiotics. Methods For the period between 1 January 2000 and 31 December 2011, resistance of Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Proteus mirabilis to third- and fourth-generation cephalosporins, meropenem, piperacillin/tazobactam, fluoroquinolones and aminoglycosides was retrospectively studied. For the assessment of selection pressure of antibiotics, a parameter of defined daily dose in absolute annual consumption (DDDatb) based on the ATC/DDD classification and in relative annual consumption (RDDDatb) as the number of defined daily doses per 100 bed-days was used. The relationship between frequency of strains resistant to a particular antibiotic and antibiotic consumption was assessed by linear regression analysis using Spearman’s correlation. The level of statistical significance was set at p?antibiotic in the following cases: piperacillin/tazobactam in Klebsiella pneumoniae, gentamicin in Klebsiella pneumoniae and Escherichia coli and amikacin in Escherichia coli and Enterobacter cloacae. Also, there was significant correlation between resistance to ceftazidime and consumption of piperacillin/tazobactam in Klebsiella pneumoniae and Escherichia coli. No relationship was found between consumption of third- and fourth-generation cephalosporins and resistance to ceftazidime or between fluoroquinolone consumption and resistance to ciprofloxacin. Conclusion The study showed the effects of both direct and indirect selection pressure on increasing resistance to gentamicin, amikacin, piperacillin/tazobactam and ceftazidime. Given the fact that no correlation was found between resistance to fluoroquinolones and consumption of either primary or secondary antibiotics, we assume that the increasing resistance to fluoroquinolones is probably due to circulation of resistance genes in the bacterial population and that this resistance was not affected by reduced use of these antibiotics. PMID:25027417

2014-01-01

55

Novel genes involved in cephalosporin biosynthesis: the three-component isopenicillin N epimerase system.  

PubMed

Cephalosporin is one of the best beta-lactam antibiotics, widely used in the treatment of infectious diseases. It is synthesized by Acremonium chrysogenum. The levels of cephalosporin produced by the improved strains obtained by classical mutation and selection procedures are still low compared to the penicillin titers obtained from the high-producing Penicillium chrysogenum strains. Most of the genes encoding the cephalosporin biosynthesis enzymes have been cloned, and some improvement of cephalosporin production has been achieved by removing bottlenecks in the pathway. One of the poorly-known steps involved in cephalosporin biosynthesis is the conversion of isopenicillin N into penicillin N catalyzed by the isopenicillin N epimerase system. This epimerization reaction is catalyzed by a two-component protein system encoded by the cefD1 and cefD2 genes that correspond, respectively, to an isopenicillinyl-CoA ligase and an isopenicillinyl-CoA epimerase. Comparative analysis of those proteins with others in the databanks provide evidence indicating that they are related to enzymes catalyzing the catabolism of toxic metabolites in animals. There are several biochemical mechanisms, reviewed in this article, for the biosynthesis of D-amino acids in secondary metabolites. The conversion of isopenicillin N to penicillin N in cephamycin-producing bacteria is mediated by a classical pyridoxal phosphate-dependent epimerase that is clearly different from the epimerization system existing in Acremonium chrysogenum. Modification of gene expression by directed manipulation of the cefD1-cefD2 bidirectional promoter region is a promising strategy for improving cephalosporin production. Improving our knowledge of the mechanism of epimerization systems is important if we wish to understand how microorganisms synthesize the high number of rare D-amino acids that are responsible, to a large extent, for the biological activities of many different secondary metabolites. PMID:15719553

Martín, Juan F; Ullán, Ricardo V; Casqueiro, Javier

2004-01-01

56

Bacterial eradication rates with shortened courses of 2nd- and 3rd-generation cephalosporins versus 10 days of penicillin for treatment of group A streptococcal tonsillopharyngitis in adults.  

PubMed

In a meta-analysis of 5 randomized controlled trials involving 1030 adults, the likelihood of bacteriologic eradication in the treatment of group A beta-hemolytic streptococcal (GAS) tonsillopharyngitis with 5 days of select cephalosporins (cefpodoxime, cefuroxime, cefotiam, and cefdinir) was noninferior to 10 days of penicillin (odds ratio, 1.46; 95% confidence interval, 0.96-2.22, P = 0.08). PMID:17908614

Pichichero, Michael E; Casey, Janet R

2007-10-01

57

Questionnaire survey of perioperative antibiotic prophylaxis in Italian surgical departments.  

PubMed

Correct antibiotic prophylaxis reduces the incidence of postoperative infections. 600 questionnaires on perioperative antibiotic prophylaxis were sent to Italian Surgical Departments. Each questionnaire included a series of 17 multi-choice-questions concerning the specific approach of the department to: organization, type, timing, duration, auditing of prophylaxis. 435 departments (72.5%) responded to the questionnaire; 50 of these were blank, so 385 out of 435 (88.5%) were suitable for statistical evaluation. Results were as follows: 90.5% of departments perform some form of prophylaxis under the control, in 90.5% of cases, of surgeons; 89.3% differentiate antibiotics according to class of operation; 67.4% give the antibiotic preoperatively and prefer i.v. injection (61.0%), mostly in the ward (56.2%); in 33.3% of cases the prophylaxis is standard (more than 2 doses), but 55.8% of Italian surgeons do not give a boost-dose in operations longer than 3 h; 54.2% of patients receive a cephalosporin (mostly III generation), with a rotation of molecules in 53.9% of cases; 71.7% of departments register the incidence of infections, but only 43.2% control the patients 30 days after surgery; finally, 54.2% of departments work together with a bacteriology laboratory active 24 hours, while in 81.7% of cases the hospital has an Infection Committee which meets together usually without a programmed date (60.3%). In conclusion, antibiotic prophylaxis in Italian Surgery Departments appears adequate, even though some problems still remain regarding time-dose-duration-schedule, rotation of molecules, excess of cephalosporins, availability of a 24-h bacteriological laboratory and infection surveillance after discharge. PMID:11892901

Colizza, S; Rossi, S; Daffina, A

2002-02-01

58

Ready for a world without antibiotics? The Pensi?res Antibiotic Resistance Call to Action  

PubMed Central

Resistance to antibiotics has increased dramatically over the past few years and has now reached a level that places future patients in real danger. Microorganisms such as Escherichia coli and Klebsiella pneumoniae, which are commensals and pathogens for humans and animals, have become increasingly resistant to third-generation cephalosporins. Moreover, in certain countries, they are also resistant to carbapenems and therefore susceptible only to tigecycline and colistin. Resistance is primarily attributed to the production of beta-lactamase genes located on mobile genetic elements, which facilitate their transfer between different species. In some rare cases, Gram-negative rods are resistant to virtually all known antibiotics. The causes are numerous, but the role of the overuse of antibiotics in both humans and animals is essential, as well as the transmission of these bacteria in both the hospital and the community, notably via the food chain, contaminated hands, and between animals and humans. In addition, there are very few new antibiotics in the pipeline, particularly for Gram-negative bacilli. The situation is slightly better for Gram-positive cocci as some potent and novel antibiotics have been made available in recent years. A strong and coordinated international programme is urgently needed. To meet this challenge, 70 internationally recognized experts met for a two-day meeting in June 2011 in Annecy (France) and endorsed a global call to action ("The Pensières Antibiotic Resistance Call to Action"). Bundles of measures that must be implemented simultaneously and worldwide are presented in this document. In particular, antibiotics, which represent a treasure for humanity, must be protected and considered as a special class of drugs. PMID:22958833

2012-01-01

59

Ready for a world without antibiotics? The Pensières Antibiotic Resistance Call to Action.  

PubMed

Resistance to antibiotics has increased dramatically over the past few years and has now reached a level that places future patients in real danger. Microorganisms such as Escherichia coli and Klebsiella pneumoniae, which are commensals and pathogens for humans and animals, have become increasingly resistant to third-generation cephalosporins. Moreover, in certain countries, they are also resistant to carbapenems and therefore susceptible only to tigecycline and colistin. Resistance is primarily attributed to the production of beta-lactamase genes located on mobile genetic elements, which facilitate their transfer between different species. In some rare cases, Gram-negative rods are resistant to virtually all known antibiotics. The causes are numerous, but the role of the overuse of antibiotics in both humans and animals is essential, as well as the transmission of these bacteria in both the hospital and the community, notably via the food chain, contaminated hands, and between animals and humans. In addition, there are very few new antibiotics in the pipeline, particularly for Gram-negative bacilli. The situation is slightly better for Gram-positive cocci as some potent and novel antibiotics have been made available in recent years. A strong and coordinated international programme is urgently needed. To meet this challenge, 70 internationally recognized experts met for a two-day meeting in June 2011 in Annecy (France) and endorsed a global call to action ("The Pensières Antibiotic Resistance Call to Action"). Bundles of measures that must be implemented simultaneously and worldwide are presented in this document. In particular, antibiotics, which represent a treasure for humanity, must be protected and considered as a special class of drugs. PMID:22958833

Carlet, Jean; Jarlier, Vincent; Harbarth, Stephan; Voss, Andreas; Goossens, Herman; Pittet, Didier

2012-01-01

60

[Structure and antibiotic resistance of urinary tract pathogens in case of infection in young patients under the conditions of North].  

PubMed

For the purpose of optimization of antibacterial treatment of urinary tract infection in 700young patients under the condition of North it was examined the responsivity of urinary tract pathogens to antibiotics in 1998-2009. The most effective group of antibiotics is revealed. The most frequent types of urinary tract pathogens are: in men - S. epidermidis, S. saprophyticus, S. aureus; in women with non-complicated UTI - E. coli, S. epidermidis, S. saprophyticus u S. aureus; with complicated - E. coli, S. saprophyticus, S. epidermidis. The abovementioned pathogens showed the low antibiotic resistance (in vitro) to gentamicin and ofloxacin; high antibiotic resistance to cephalosporin (3rd generation) and ciprofloxacin. It is better to prescribe ofloxacin and cefotaxime for patients with complicated UTI; for women with non-complicated UTI - ofloxacin and ceftriaxone. It is necessary to consider nephrotoxicity and low compliance before prescription of gentamicin. PMID:25046922

Plekhanov, V N

2014-02-01

61

Urine from Treated Cattle Drives Selection for Cephalosporin Resistant Escherichia coli in Soil  

PubMed Central

The U.S. Food and Drug Administration recently issued new rules for using ceftiofur in food animals in part because of an increasing prevalence of enteric bacteria that are resistant to 3rd-generation cephalosporins. Parenteral ceftiofur treatment, however, has limited effects on enteric bacteria so we tested the hypothesis that excreted ceftiofur metabolites exert significant selection pressure for ceftiofur-resistant Escherichia coli in soil. Test matrices were prepared by mixing soil with bovine feces and adding urine containing ceftiofur metabolites (CFM) (0 ppm, ?50 ppm and ?100 ppm). Matrices were incubated at 23°C or 4°C for variable periods of time after which residual CFM was quantified using a bioassay. BlaCMY-2 plasmid-bearing ceftiofur resistant (cefR) E. coli and one-month old calves were used to study the selection effects of CFM and transmission of cefR bacteria from the environment back to animals. Our studies showed that urinary CFM (?13 ppm final concentration) is biologically degraded in soil within 2.7 days at 23°C, but persists up to 23.3 days at 4°C. Even short-term persistence in soil provides a >1 log10 advantage to resistant E. coli populations, resulting in significantly prolonged persistence of these bacteria in the soil (?two months). We further show that resistant strains readily colonize calves by contact with contaminated bedding and without antibiotic selection pressure. Ceftiofur metabolites in urine amplify resistant E. coli populations and, if applicable to field conditions, this effect is far more compelling than reported selection in vivo after parenteral administration of ceftiofur. Because ceftiofur degradation is temperature dependent, these compounds may accumulate during colder months and this could further enhance selection as seasonal temperatures increase. If cost-effective engineered solutions can be developed to limit ex vivo selection, this may limit proliferation for ceftiofur resistant enteric bacteria while preserving the ability to use this important antibiotic in food animal production. PMID:23145021

Subbiah, Murugan; Shah, Devendra H.; Besser, Thomas E.; Ullman, Jeffrey L.; Call, Douglas R.

2012-01-01

62

Novel metagenome-derived carboxylesterase that hydrolyzes ?-lactam antibiotics.  

PubMed

It has been proposed that family VIII carboxylesterases and class C ?-lactamases are phylogenetically related; however, none of carboxylesterases has been reported to hydrolyze ?-lactam antibiotics except nitrocefin, a nonclinical chromogenic substrate. Here, we describe the first example of a novel carboxylesterase derived from a metagenome that is able to cleave the amide bond of various ?-lactam substrates and the ester bond of p-nitrophenyl esters. A clone with lipolytic activity was selected by functional screening of a metagenomic library using tributyrin agar plates. The sequence analysis of the clone revealed the presence of an open reading frame (estU1) encoding a polypeptide of 426 amino acids, retaining an S-X-X-K motif that is conserved in class C ?-lactamases and family VIII carboxylesterases. The gene was overexpressed in Escherichia coli, and the purified recombinant protein (EstU1) was further characterized. EstU1 showed esterase activity toward various chromogenic p-nitrophenyl esters. In addition, it exhibited hydrolytic activity toward nitrocefin, leading us to investigate whether EstU1 could hydrolyze ?-lactam antibiotics. EstU1 was able to hydrolyze first-generation ?-lactam antibiotics, such as cephalosporins, cephaloridine, cephalothin, and cefazolin. In a kinetic study, EstU1 showed a similar range of substrate affinities for both p-nitrophenyl butyrate and first-generation cephalosporins while the turnover efficiency for the latter was much lower. Furthermore, site-directed mutagenesis studies revealed that the catalytic triad of EstU1 plays a crucial role in hydrolyzing both ester bonds of p-nitrophenyl esters and amide bonds of the ?-lactam ring of antibiotics, implicating the predicted catalytic triad of EstU1 in both activities. PMID:21908637

Jeon, Jeong Ho; Kim, Soo-Jin; Lee, Hyun Sook; Cha, Sun-Shin; Lee, Jung Hun; Yoon, Sang-Hong; Koo, Bon-Sung; Lee, Chang-Muk; Choi, Sang Ho; Lee, Sang Hee; Kang, Sung Gyun; Lee, Jung-Hyun

2011-11-01

63

Novel Metagenome-Derived Carboxylesterase That Hydrolyzes ?-Lactam Antibiotics?†  

PubMed Central

It has been proposed that family VIII carboxylesterases and class C ?-lactamases are phylogenetically related; however, none of carboxylesterases has been reported to hydrolyze ?-lactam antibiotics except nitrocefin, a nonclinical chromogenic substrate. Here, we describe the first example of a novel carboxylesterase derived from a metagenome that is able to cleave the amide bond of various ?-lactam substrates and the ester bond of p-nitrophenyl esters. A clone with lipolytic activity was selected by functional screening of a metagenomic library using tributyrin agar plates. The sequence analysis of the clone revealed the presence of an open reading frame (estU1) encoding a polypeptide of 426 amino acids, retaining an S-X-X-K motif that is conserved in class C ?-lactamases and family VIII carboxylesterases. The gene was overexpressed in Escherichia coli, and the purified recombinant protein (EstU1) was further characterized. EstU1 showed esterase activity toward various chromogenic p-nitrophenyl esters. In addition, it exhibited hydrolytic activity toward nitrocefin, leading us to investigate whether EstU1 could hydrolyze ?-lactam antibiotics. EstU1 was able to hydrolyze first-generation ?-lactam antibiotics, such as cephalosporins, cephaloridine, cephalothin, and cefazolin. In a kinetic study, EstU1 showed a similar range of substrate affinities for both p-nitrophenyl butyrate and first-generation cephalosporins while the turnover efficiency for the latter was much lower. Furthermore, site-directed mutagenesis studies revealed that the catalytic triad of EstU1 plays a crucial role in hydrolyzing both ester bonds of p-nitrophenyl esters and amide bonds of the ?-lactam ring of antibiotics, implicating the predicted catalytic triad of EstU1 in both activities. PMID:21908637

Jeon, Jeong Ho; Kim, Soo-Jin; Lee, Hyun Sook; Cha, Sun-Shin; Lee, Jung Hun; Yoon, Sang-Hong; Koo, Bon-Sung; Lee, Chang-Muk; Choi, Sang Ho; Lee, Sang Hee; Kang, Sung Gyun; Lee, Jung-Hyun

2011-01-01

64

Inactivation of Antibiotics and the Dissemination of Resistance Genes  

Microsoft Academic Search

The emergence of multidrug-resistant bacteria is a phenomenon of concern to the clinician and the pharmaceutical industry, as it is the major cause of failure in the treatment of infectious diseases. The most common mechanism of resistance in pathogenic bacteria to antibiotics of the aminoglycoside, beta-lactam (penicillins and cephalosporins), and chloramphenicol types involves the enzymic inactivation of the antibiotic by

Julian Davies

1994-01-01

65

[Pharmacokinetics of a new cephalosporin, cefoperazone].  

PubMed

Cefoperazone is a semi-synthetic cephalosporin for parenteral use with an extended antibacterial spectrum covering Pseudomonas aeruginosa, Enterobacter cloacae and Serratia marcescens. Its pharmacokinetic properties were studied in 8 healthy subjects after 2 intravenous infusions of 2 g of the drug at a 12-hour interval. The mean peak serum concentrations were 134 +/- 16 microgram/ml and 143 microgram/ml. Cefoperazone was shown to possess a long half-life for a cephalosporin (1.7 hours). In our concentration range the drug is 90% protein bound. The apparent volume of distribution was a mean 11.4 liters and the renal clearance 18 ml/min. The cumulative urinary excretion was small, viz. 23% in 12 hours, indicating that there should be no need to modify the dosage regimen in renal failure. Comparison of in vitro studies with the pharmacokinetic properties show that 2 g cefoperazone given intravenously twice a day should inhibit most sensitive bacteria. PMID:538442

Allaz, A F; Dayer, P; Fabre, J; Rudhardt, M; Balant, L

1979-12-29

66

Effect of time interval on tissue concentrations of cephalosporins after tourniquet inflation. Highest levels achieved by administration 20 minutes before inflation.  

PubMed

We studied the effect of different time intervals between antibiotic administration and tourniquet inflation in 62 patients undergoing reconstructive surgery in the lower extremities. The in vivo concentrations in soft tissue and bone of 3 cephalosporins (ceftazidime, ceftriaxone and ceforanide) were determined. Our findings suggest that the highest tissue concentrations were achieved by administration 20 min before tourniquet inflation. PMID:7740948

Dounis, E; Tsourvakas, S; Kalivas, L; Giamaçellou, H

1995-04-01

67

The realm of penicillin G acylase in ?-lactam antibiotics  

Microsoft Academic Search

Penicillin G acylase (PGA; EC 3.5.1.11) is a hydrolytic enzyme that acts on the side chains of penicillin G, cephalosporin G and related antibiotics to produce the ?-lactam antibiotic intermediates 6-amino penicillanic acid (6-APA) and 7-amino des-acetoxy cephalosporanic acid (7-ADCA), with phenyl acetic acid (PAA) as a common by-product. These antibiotic intermediates are among the potential building blocks of semi-synthetic

Anuj K. Chandel; L. Venkateswar Rao; M. Lakshmi Narasu; Om V. Singh

2008-01-01

68

Phage-Antibiotic Synergy (PAS): beta-Lactam and Quinolone Antibiotics Stimulate Virulent Phage Growth  

Microsoft Academic Search

Although the multiplication of bacteriophages (phages) has a substantial impact on the biosphere, comparatively little is known about how the external environment affects phage production. Here we report that sub-lethal concentrations of certain antibiotics can substantially stimulate the host bacterial cell's production of some virulent phage. For example, a low dosage of cefotaxime, a cephalosporin, increased an uropathogenic Escherichia coli

André M. Comeau; Françoise Tétart; Sabrina N. Trojet; Marie-Françoise Prère; H. M. Krisch; Debbie Fox

2007-01-01

69

The eradication of bacterial persisters with antibiotic-generated hydroxyl radical  

E-print Network

During Mycobacterium tuberculosis infection, a population of bacteria likely becomes refractory to antibiotic killing in the absence of genotypic resistance, making treatment challenging. We describe an in vitro model ...

Haseley, Nathan Scott

70

Surveillance of Antibiotic Consumption Using the "Focus of Infection" Approach in 2 Hospitals in Ujjain, India  

PubMed Central

Antibiotic surveillance initiatives are limited in resource-constrained settings. In the present study, a quantitative comparison of antibiotic use rates for suspected infections in 2 hospitals in India was performed using the “focus of infection” approach to identify targets for quality improvement in antibiotic prescription patterns in hospitalized patients. Methods This observational study was carried out in one teaching and one nonteaching hospital. All the patients with suspected bacterial etiology were included. Data on the prescribed antibiotics and the focus of infection were prospectively collected using a structured questionnaire. Each diagnosis was further reviewed and confirmed by an independent consultant. The prescribed antibiotics were coded according to the World Health Organization Anatomic Therapeutic Classification (ATC) index with the defined daily dose (DDD) methodology. Focus-specific DDDs were calculated per hundred patient days (DDD/HPD). Results A total of 6026 patients were included from 72 participating physicians out of available 75 physicians. Overall antibiotic prescribing was higher by 5 percentage points in the teaching hospital (95%) than in the nonteaching hospital (90%). Quinolones (ciprofloxacin constituting 86% of DDD/HPD) were the highest prescribed class in the teaching hospital, and third-generation cephalosporins (with ceftriaxone and ceftriaxone/sulbactam constituting 40% and 28% of the DDD/HPD, respectively), in the nonteaching hospital. The targets identified for improvement were the following: longer than recommended duration of prophylaxis and lack of distinction between prophylaxis and therapy among surgical patients; irrational antibiotic prescribing in gastroenteritis; overuse of quinolones and lack of use of penicillin in pneumonia; overuse of quinolones and lack of use of doxycycline and macrolides in genital infections; and overreliance on antibiotics for treating skin and soft tissue infections. Conclusions Providing a quantitative comparison of antibiotic use rates for suspected infections, using the “focus of infection” approach along with the ATC/DDD methodology, appears appropriate for identifying targets for quality improvement with regards to antibiotic prescribing. PMID:22715402

Pathak, Ashish; Mahadik, Kalpana; Dhaneria, Surya Prakesh; Sharma, Ashish; Eriksson, Bo; Lundborg, Cecilia Stalsby

2012-01-01

71

Detection of Favorable Oral Cephalosporin-Clavulanate Interactions by In Vitro Disk Approximation Susceptibility Testing of Extended-Spectrum-Beta-Lactamase-Producing Members of the Enterobacteriaceae  

PubMed Central

Extended-spectrum-beta-lactamase (ESBL)-producing members of the Enterobacteriaceae are often resistant to multiple drug classes, making therapy of urinary infections with oral antibiotics difficult. Previously it was shown that amoxicillin-clavulanate can provide clavulanate inhibition of ESBLs and protect an oral cephalosporin present in combination when tested by broth microdilution. This study has shown that disk approximation testing could detect favorable cephalosporin-clavulanate interactions among a group of 101 previously characterized members of the Enterobacteriaceae with CTX-M, SHV, or TEM ESBLs. PMID:22170910

Campbell, Jennifer D.; Lewis, James S.; McElmeel, M. Leticia; Fulcher, Letitia C.

2012-01-01

72

Use of a Heavy Inoculum in the In Vitro Evaluation of the Anti-Staphylococcal Activity of 19 Cephalosporins  

PubMed Central

The in vitro activity of 19 cephalosporins against 105 clinical isolates of Staphylococcus aureus and S. epidermidis was determined by using a heavy inoculum, i.e., 108 to 109 organisms per ml, to maximally challenge the antibiotics. The anti-staphylococcal activities of cephaloridine and 87/312 were consistently decreased by the use of a heavy inoculum when compared with the activity obtained with two less-concentrated inocula. The activity of most of the other compounds was also decreased with the use of a heavy inoculum, but this was observed only with selected isolates. Cephapirin, cephalothin, and cefazaflur were the most active drugs against the methicillin-susceptible isolates. Cephaloridine, cefamandole, cefazaflur, and 87/312 had substantial activity against methicillin-resistant staphylococci even with heavy inocula. With the exception of cefaclor against S. aureus, the orally absorbed cephalosporins were generally one-half to one-sixteenth as active as the parenterally administered cephalosporins. The median minimal inhibitory concentrations of five of the 12 parenteral cephalosporins were lower with the methicillin-susceptible S. aureus than with the methicillin-susceptible S. epidermidis strains. PMID:352261

Laverdiere, Michel; Welter, Diane; Sabath, L. D.

1978-01-01

73

Peptidoglycan Transpeptidase Inhibition in Pseudomonas aeruginosa and Escherichia coli by Penicillins and Cephalosporins  

PubMed Central

Peptidoglycan transpeptidase activity has been studied in cells of Escherichia coli 146 and Pseudomonas aeruginosa 56 made permeable to exogenous, nucleotide-sugar peptidoglycan precursors by ether treatment. Transpeptidase activity was inhibited, in both organisms, by a range of penicillins and cephalosporins, the Pseudomonas enzyme being more sensitive to inhibition in each case. Conversely, growth of E. coli 146 was more susceptible to these antibiotics than growth of P. aeruginosa 56. Furthermore, similar transpeptidase inhibition values were ob-obtained for the four penicillins examined against the Pseudomonas enzyme, although only two of these (carbenicillin and pirbenicillin) inhibited the growth of this organism. We therefore conclude that the high resistance of P. aeruginosa 56 to growth inhibition by most ?-lactam antibiotics cannot be due to an insensitive peptidoglycan transpeptidase. PMID:111613

Moore, Brian A.; Jevons, Sidney; Brammer, Keith W.

1979-01-01

74

Antimicrobial sensitivity patterns of cerebrospinal fluid (CSF) isolates in Namibia: implications for empirical antibiotic treatment of meningitis  

PubMed Central

Objective Bacterial meningitis is a medical emergency associated with high mortality rates. Cerebrospinal fluid (CSF) culture is the “gold standard” for diagnosis of meningitis and it is important to establish the susceptibility of the causative microorganism to rationalize treatment. The Namibia Standard Treatment Guidelines (STGs) recommends initiation of empirical antibiotic treatment in patients with signs and symptoms of meningitis after taking a CSF sample for culture and sensitivity. The objective of this study was to assess the antimicrobial sensitivity patterns of microorganisms isolated from CSF to antibiotics commonly used in the empirical treatment of suspected bacterial meningitis in Namibia. Methods This was a cross-sectional descriptive study of routinely collected antibiotic susceptibility data from the Namibia Institute of Pathology (NIP) database. Results of CSF culture and sensitivity from January 1, 2009 to May 31, 2012, from 33 state hospitals throughout Namibia were analysed. Results The most common pathogens isolated were Streptococcus species, Neisseria meningitidis, Haemophilus influenzae, Staphylococcus, and Escherichia coli. The common isolates from CSF showed high resistance (34.3% –73.5%) to penicillin. Over one third (34.3%) of Streptococcus were resistance to penicillin which was higher than 24.8% resistance in the United States. Meningococci were susceptible to several antimicrobial agents including penicillin. The sensitivity to cephalosporins remained high for Streptococcus, Neisseria, E. coli and Haemophilus. The highest percentage of resistance to cephalosporins was seen among ESBL K. pneumoniae (n?=?7, 71%–100%), other Klebsiella species (n?=?7, 28%–80%), and Staphylococcus (n?=?36, 25%–40%). Conclusions The common organisms isolated from CSF were Streptococcus Pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Staphylococcus, and E. coli. All common organisms isolated from CSF showed high sensitivity to cephalosporins used in the empirical treatment of meningitis. The resistance of the common isolates to penicillin is high. Most ESBL K. pneumoniae were isolated from CSF samples drawn from neonates and were found to be resistant to the antibiotics recommended in the Namibia STGs. Based on the above findings, it is recommended to use a combination of aminoglycoside and third-generation cephalosporin to treat non–ESBL Klebsiella isolates. Carbapenems (e.g., meropenem) and piperacillin/tazobactam should be considered for treating severely ill patients with suspected ESBL Klebsiella infection. Namibia should have a national antimicrobial resistance surveillance system for early detection of antibiotics that may no longer be effective in treating meningitis and other life-threatening infections due to resistance. PMID:24764539

2013-01-01

75

Pharmacological aspects of the antibiotics used for urological diagnostic procedures.  

PubMed

Surgical antimicrobial prophylaxis is the use of an antibiotic before, during, or shortly after a urological procedure to prevent postoperative infections such as urinary tract or wound infection. The optimal antimicrobial drug must be microbiologically active against the most frequent potential pathogens and have good pharmacological properties. Correct timing of antimicrobial prophylaxis is the first critical issue in determining treatment efficacy. The antibiotic must be administered before the start of the surgical procedure in order to ensure a high tissue level at the time of microbial contamination. If using an oral antibiotic, this must be administered 1-3 hours before the operation and a parenteral antibiotic should be administered at the induction of anaesthesia. The antibiotics potentially useful for antimicrobial prophylaxis are the beta-lactams, cotrimoxazole, fluoroquinolones, and fosfomycin trometamol. The criteria for choosing the optimal antibiotic include an appropriate antimicrobial spectrum, favourable pharmacokinetic parameters (especially good tissue penetration), and elevated safety or tolerability. The use of cotrimoxazole must be restricted due to increasing chemoresistance. Unfortunately fluoroquinolone-based regimens, once the mainstay of prophylaxis guidelines, are increasingly ineffective due to a constant increase in multidrug-resistant (MDR) Gram-negative bacteria. The same concerns apply with regard to the second and third generation cephalosporins that have problems of resistance and, if administered orally, do not sufficiently penetrate prostatic tissue. An appropriate beta-lactam could be an aminopenicillin combined with a beta-lactamase inhibitor. Fosfomycin trometamol can also be a good potential choice due to its elevated activity against MDR Gram-negative bacteria and its favourable pharmacokinetic parameters, including an elevated penetration into prostatic tissue. PMID:25245708

Mazzei, Teresita; Diacciati, Sara

2014-10-01

76

Efficacy of cryptdin-2 as an adjunct to antibiotics from various generations against salmonella.  

PubMed

Emerging drug resistance in Salmonella coupled with the recent poor success rate of antibiotic discovery programs of the pharmaceutical industry is a cause for significant concern. It has forced the scientific community to look for alternative new classes of antimicrobial compounds. In this context, combinations of antimicrobial peptides (AMPs) and conventional antibiotics have gained interest owing to their versatile applications. The present study was therefore planned to evaluate the synergistic effects, if any, of cryptdin-2, a mouse Paneth cell alpha-defensin, in combination with four different antibiotics i.e. ciprofloxacin, ceftriaxone, cefotaxime and chloramphenicol, which are conventionally used against Salmonella. Minimum bactericidal concentrations of the selected antimicrobial agents were determined by micro and macro broth dilution assays. In-vitro synergy between the agents was evaluated by fractional bactericidal concentration index (checkerboard test) and time-kill assay. Cryptdin-2-ciprofloxacin, cryptdin-2-ceftriaxone and cryptdin-2-cefotaxime combinations were found synergistic as evident by in vitro assays. This synergism provides an additional therapeutic choice by allowing the use of conventional antibiotics in conjunction with AMPs against MDR Salmonella. PMID:24891740

Singh, Aman Preet; Prabha, Vijay; Rishi, Praveen

2014-09-01

77

Value of integron detection for predicting antibiotic resistance in patients with Gram-negative septicaemia.  

PubMed

Multidrug-resistant Enterobacteriaceae are a major public health threat and complicate the choice of drugs for empirical antibiotic therapy, especially in sepsis patients who require rapid, appropriate treatment. The objective of this study was to examine the value of integrons as a global predictive marker of acquired antibiotic resistance in septicaemia-causing Enterobacteriaceae by direct detection in positive blood cultures. The integron genetic marker can be detected in a single test, whereas multiple PCRs are needed to detect the hundreds of known antibiotic resistance genes. A total of 166 positive blood cultures were included in the study, and integrons were detected with a quantitative PCR method both in positive blood cultures and isolated Enterobacteriaceae. The results of integron detection directly on positive blood cultures were consistent in 98.8% of cases with integron detection in isolated Enterobacteriaceae. Negative predictive values (NPVs) were >90% for resistance to third-generation cephalosporins, aminoglycosides, ciprofloxacin and trimethoprim/sulfamethoxazole. In the current context of antibiotic stewardship, these good NPVs indicate that this method might be useful for preserving broad-spectrum antibiotics. The results of this proof-of-concept study must be confirmed in order to demonstrate the clinical relevance of integron detection, not only in positive blood cultures but also, to gain time, in raw biological samples. PMID:25130099

Barraud, Olivier; François, Bruno; Chainier, Delphine; Vignaud, Julie; Ploy, Marie-Cécile

2014-10-01

78

Evolution of an Antibiotic Resistance Enzyme Constrained by Stability and Activity Trade-offs  

Microsoft Academic Search

Pressured by antibiotic use, resistance enzymes have been evolving new activities. Does such evolution have a cost? To investigate this question at the molecular level, clinically isolated mutants of the ?-lactamase TEM-1 were studied. When purified, mutant enzymes had increased activity against cephalosporin antibiotics but lost both thermodynamic stability and kinetic activity against their ancestral targets, penicillins. The X-ray crystallographic

Xiaojun Wang; George Minasov; Brian K. Shoichet

2002-01-01

79

Enhancing the antibiotic antibacterial effect by sub lethal tellurite concentrations: tellurite and cefotaxime act synergistically in Escherichia coli.  

PubMed

The emergence of antibiotic-resistant pathogenic bacteria during the last decades has become a public health concern worldwide. Aiming to explore new alternatives to treat antibiotic-resistant bacteria and given that the tellurium oxyanion tellurite is highly toxic for most microorganisms, we evaluated the ability of sub lethal tellurite concentrations to strengthen the effect of several antibiotics. Tellurite, at nM or µM concentrations, increased importantly the toxicity of defined antibacterials. This was observed with both gram negative and gram positive bacteria, irrespective of the antibiotic or tellurite tolerance of the particular microorganism. The tellurite-mediated antibiotic-potentiating effect occurs in laboratory and clinical, uropathogenic Escherichia coli, especially with antibiotics disturbing the cell wall (ampicillin, cefotaxime) or protein synthesis (tetracycline, chloramphenicol, gentamicin). In particular, the effect of tellurite on the activity of the clinically-relevant, third-generation cephalosporin (cefotaxime), was evaluated. Cell viability assays showed that tellurite and cefotaxime act synergistically against E. coli. In conclusion, using tellurite like an adjuvant could be of great help to cope with several multi-resistant pathogens. PMID:22536386

Molina-Quiroz, Roberto C; Muñoz-Villagrán, Claudia M; de la Torre, Erick; Tantaleán, Juan C; Vásquez, Claudio C; Pérez-Donoso, José M

2012-01-01

80

Mutational effect of Penicillium chrysogenum on Antibiotic Production  

Microsoft Academic Search

?-Lactams like penicillin and cephalosporin are among the oldest known antibiotics used against bacterial infections. Industrially, penicillin is produced by the filamentous fungus Penicillium chrysogenum. The most common method used to obtain high yielding mutants by strain improvement with classical mutagenesis is by treating a population with a mutagenic agent and plating out the colonies random selected. The present study

M. Veerapagu; K. R Jeya; K. Ponmurugan

81

A Single Prophylactic Antibiotic for Emergency Appendicectomy  

Microsoft Academic Search

This paper reports the results of a prospective randomized study of antibiotic prophylaxis in 200 patients over the age of 12 years undergoing emergency appendicectomy at Al-Jala Hospital for Trauma and Emergency Surgery, Benghazi. We have compared the efficacy of ceftriaxone, a long-acting broad-spectrum cephalosporin with that of our routine regimen consisting of metronidazole, gentamicin and ampicillin, given together. Ceftriaxone

M. E. El-Mufti; F. Rakas; A. Glessa; B. Sanallah; A. Abusidra

1989-01-01

82

Review of the spectrum and potency of orally administered cephalosporins and amoxicillin/clavulanate.  

PubMed

The antimicrobial spectrum and in vitro potency of the most frequently prescribed orally administered cephalosporins (cefaclor, cefdinir, cefpodoxime, cefprozil, cefuroxime axetil, cephalexin) and amoxicillin/clavulanate are reviewed. These beta-lactam agents have been widely used in the outpatient arena for the treatment of community-acquired respiratory tract and other mild-to-moderate infections. The data presented here were obtained from critical review articles on each of these compounds. Cephalexin and cefaclor were among the least potent and had the narrowest antimicrobial spectrums against the pathogens evaluated. In contrast, cefdinir, cefpodoxime, cefprozil, and cefuroxime were highly active against penicillin-susceptible Streptococcus pneumoniae and retained some activity against penicillin-intermediate strains, whereas amoxicillin/clavulanate was the most active against S. pneumoniae, including most penicillin nonsusceptible strains. Amoxicillin/clavulanate and cefdinir were the most potent compounds against methicillin (oxacillin)-susceptible Staphylococcus aureus, whereas cefpodoxime was the most potent compound against Haemophilus influenzae. Amoxicillin/clavulanate, cefdinir, and cefpodoxime were also active against Moraxella catarrhalis, including beta-lactamase-producing strains. In summary, orally administered "3rd-generation" or extended spectrum cephalosporins exhibited more balanced spectrums of activity against the principal bacterial pathogens responsible for outpatient respiratory tract and other infections when compared with other widely used oral cephalosporins of earlier generations or amoxicillin alone. PMID:17292577

Sader, Helio S; Jacobs, Michael R; Fritsche, Thomas R

2007-03-01

83

QSAR Study of -Lactam Antibiotic Efflux by the Bacterial Multidrug Resistance Pump AcrB Mrcia Miguel Castro Ferreira (PQ) and Rudolf Kiralj (PQ)  

E-print Network

QSAR Study of -Lactam Antibiotic Efflux by the Bacterial Multidrug Resistance Pump AcrB Márcia antibiotics (penicillins and cephalosporins) as substrates of multidrug resistance efflux membrane pump Acr M. M. C., Kiralj R., "QSAR study of -lactam antibiotic efflux by the bacterial multidrug resistance

Ferreira, Márcia M. C.

84

Purification and characterization of a cephalosporin esterase from Rhodosporidium toruloides.  

PubMed Central

A novel cephalosporin esterase (EC 3.1.1.41) from Rhodosporidium toruloides was purified to gel electrophoretic homogeneity. The enzyme is a glycoprotein with a molecular mass of 80 kDa. Upon deglycosylation, several forms of the enzyme were observed with a molecular mass range between 60 and 66 kDa. The isoelectric point of the enzyme is approximately 5.6, with the pH optimum for activity occurring at 6.0. The optimal activity of the enzyme occurred at 25 degrees C, with the enzyme rapidly losing activity at temperatures above 25 degrees C. The enzyme deacetylated a variety of cephalosporin derivatives, including cephalosporin C; the Km for this substrate is 51.8 mM, and the Vmax is 7.9 mumol/min/mg. In addition to cephalosporins, the enzyme hydrolyzed short-chain p-nitrophenyl esters, with the activity decreasing with increasing ester chain length. The enzyme also has the ability to acetylate desacetyl cephalosporins in high yields under mild conditions in the presence of various acetyl donors. A comparison of the physical properties of the esterase with those of other well-characterized cephalosporin esterases indicates that the enzyme is unique in this class. PMID:9406399

Politino, M; Tonzi, S M; Burnett, W V; Romancik, G; Usher, J J

1997-01-01

85

Pharmacokinetics of cephalosporins in the neonate: a review.  

PubMed

The aim of this work was to review the published data on the pharmacokinetics of cephalosporins in neonates to provide a critical analysis of the literature as a useful tool for physicians. The bibliographic search was performed for articles published up to December 3, 2010, using PubMed. In addition, the book Neofax: A Manual of Drugs Used in Neonatal Care by Young and Mangum was consulted. The cephalosporins are mainly eliminated by the kidneys, and their elimination rates are reduced at birth. As a consequence, clearance is reduced and t1/2 is more prolonged in the neonate than in more mature infants. The neonate's substantial body water content creates a large volume of distribution (Vd) of cephalosporins, as these drugs are fairly water soluble. Postnatal development is an important factor in the maturation of the neonate, and as postnatal age proceeds, the clearance of cephalosporins increases. The maturation of the kidney governs the pharmacokinetics of cephalosporins in the infant. Clearance and t1/2 are influenced by development, and this must be taken into consideration when planning a cephalosporin dosage regimen for the neonate. PMID:21876985

Pacifici, Gian Maria

2011-01-01

86

Targeting metallo-carbapenemases via modulation of electronic properties of cephalosporins.  

PubMed

The global proliferation of metallo-carbapenemase-producing Enterobacteriaceae has created an unmet need for inhibitors of these enzymes. The rational design of metallo-carbapenemase inhibitors requires detailed knowledge of their catalytic mechanisms. Nine cephalosporins, structurally identical except for the systematic substitution of electron-donating and withdrawing groups in the para position of the styrylbenzene ring, were synthesized and utilized to probe the catalytic mechanism of New Delhi metallo-?-lactamase (NDM-1). Under steady-state conditions, Km values were all in the micromolar range (1.5-8.1 ?M), whereas kcat values varied widely (17-220 s-1). There were large solvent deuterium isotope effects for all substrates under saturating conditions, suggesting a proton transfer is involved in the rate-limiting step. Pre-steady-state UV-visible scans demonstrated the formation of short-lived intermediates for all compounds. Hammett plots yielded reaction constants (?) of -0.34±0.02 and -1.15±0.08 for intermediate formation and breakdown, respectively. Temperature-dependence experiments yielded ?G‡ values that were consistent with the Hammett results. These results establish the commonality of the formation of an azanide intermediate in the NDM-1-catalysed hydrolysis of a range cephalosporins with differing electronic properties. This intermediate is a promising target for judiciously designed ?-lactam antibiotics that are poor NDM-1 substrates and inhibitors with enhanced active-site residence times. PMID:25220027

Yang, Hao; Young, Heather; Yu, Sophia; Sutton, Larry; Crowder, Michael W

2014-12-01

87

Effect of loading rate and HRT on the removal of cephalosporin and their intermediates during the operation of a membrane bioreactor treating pharmaceutical wastewater  

Microsoft Academic Search

The viability of treating high?concentration antibiotic wastewater by an anaerobic membrane bioreactor was studied using submerged flat sheet membrane. The objective of the study was to determine the effect of organic loading rate and hydraulic retention time on the removal of cephalosporin derivative, viz. cephalexin, and the intermediates 7?amino?3?deacetoxycephalosporanic acid (7?ADCA) and acyl group (phenyl acetic acid) in an anaerobic

R. Saravanane; S. Sundararaman

2009-01-01

88

Protein antigens of encapsulated Klebsiella pneumoniae surface exposed after growth in the presence of subinhibitory concentrations of cephalosporins.  

PubMed Central

It recently has been reported by us that cephalosporins, at a concentration below that influencing growth rate, reduced the production of enterochelin and capsule formation of iron-depleted Klebsiella pneumoniae. We now report on the antigenicity of the outer membrane components and surface-exposed protein antigens of iron-depleted cells grown in the presence or absence of cephalosporins. All major outer membrane proteins, including iron-regulated membrane proteins, were immunogenic. Encapsulated K. pneumoniae grown in antibiotic-free media had three protein antigens (60, 35.5, and 32.5 kilodaltons) exposed on the surface that were accessible to antibodies. Growth of the same cultures in the presence of subinhibitory concentrations of cephalosporins resulted in the exposure of a greater number of protein antigenic determinants, including iron-regulated membrane proteins, which become readily accessible to antibodies. It was also found that immunoblotting was generally more sensitive than conventional staining of the acrylamide gel with Coomassie blue in the detection of proteins. Images PMID:3914857

Kadurugamuwa, J L; Anwar, H; Brown, M R; Zak, O

1985-01-01

89

Antibiotic regimens for treating acute pelvic inflammatory disease. An evaluation.  

PubMed

A statistical analysis of 58 reports involving 101 clinical trials and over 4,000 patients revealed that there was no statistically significant difference in the cure rates between single-agent and combination therapy. Also, there was no difference in the cure rates between antibiotic regimens that cover Chlamydia trachomatis and those that do not. However, there was a difference in cure rates when regimens with good antianaerobe activity were compared to those with poor coverage of anaerobes. There was a statistically significantly higher cure rate when "newer" regimens (mainly the second and third generations of cephalosporins and newer penicillins) were compared to "older" regimens (mainly penicillin and tetracycline). In 91 comparisons there were no statistically significant differences between regimens with a > 90% cure rate. Optimum therapy is discussed in terms of the cure rate, coverage of known pathogens and antibiotic toxicity. The original and revised recommendations of the Centers for Disease Control for the treatment of acute pelvic inflammatory disease are also reviewed. PMID:8040846

Dodson, M G

1994-04-01

90

Mortality associated with community-acquired cephalosporin-resistant Escherichia coli in patients admitted to a district hospital in a resource-limited setting  

PubMed Central

Studies performed in developed countries have shown that infections by third generation cephalosporin resistant Escherichia coli (G3CREC) are associated with increased mortality, but data from developing countries are scarce. In this observational study, we collected clinical and microbiological information of 194 patients admitted to a district hospital in India who had community-acquired isolation of Escherichia coli. The proportion of patients with G3CREC was 79.4%. In a multivariable logistic regression analysis, factors associated with 21-day mortality were isolation from a normally sterile site, HIV infection and isolation of G3CREC. Strains of Escherichia coli isolated from normally sterile sites had lower levels of resistance to quinolones and beta-lactam antibiotics. The proportion of meropenem and ciprofloxacin resistance was 11.1% and 80.9% respectively. The high proportion of G3CREC in the community and the association of G3CREC with 21-day mortality indicate that G3CREC is a major public health problem in developing countries. PMID:24765475

Alvarez-Uria, Gerardo; Priyadarshini, Uvummala; Naik, Praveen K.; Midde, Manoranjan; Reddy, Raghuprakash

2012-01-01

91

Mortality associated with community-acquired cephalosporin-resistant Escherichia coli in patients admitted to a district hospital in a resource-limited setting.  

PubMed

Studies performed in developed countries have shown that infections by third generation cephalosporin resistant Escherichia coli (G3CREC) are associated with increased mortality, but data from developing countries are scarce. In this observational study, we collected clinical and microbiological information of 194 patients admitted to a district hospital in India who had community-acquired isolation of Escherichia coli. The proportion of patients with G3CREC was 79.4%. In a multivariable logistic regression analysis, factors associated with 21-day mortality were isolation from a normally sterile site, HIV infection and isolation of G3CREC. Strains of Escherichia coli isolated from normally sterile sites had lower levels of resistance to quinolones and beta-lactam antibiotics. The proportion of meropenem and ciprofloxacin resistance was 11.1% and 80.9% respectively. The high proportion of G3CREC in the community and the association of G3CREC with 21-day mortality indicate that G3CREC is a major public health problem in developing countries. PMID:24765475

Alvarez-Uria, Gerardo; Priyadarshini, Uvummala; Naik, Praveen K; Midde, Manoranjan; Reddy, Raghuprakash

2012-05-29

92

Antibiotics and suppression of lymphocyte function in vitro.  

PubMed Central

The effects on the mitogenic response of human T lymphocytes were studied for 20 different antibiotics. No apparent inhibitory effect could be detected for penicillins, cephalosporins, aminoglycosides, chloramphenicol, sulfamethoxazole, trimethoprim, nalidixic acid, and 5-fluorocytosine. There were effects at high concentrations with erythromycin, clindamycin, and rifampin, and these antibiotics could also be shown to depress the mitogenic response of B lymphocytes. With fusidic acid, nitrofurantoin, and doxycycline there was an inhibiting effect at low concentrations on the mitogenic responses of B and T lymphocytes and on in vitro antibody production. Protein synthesis in unstimulated lymphocytes was also inhibited. Some antibiotics thus may impair the function of human lymphocytes in vitro. PMID:316685

Banck, G; Forsgren, A

1979-01-01

93

Improving the quality of antibiotic prescribing in the NHS by developing a new Antimicrobial Stewardship Programme: Start Smart--Then Focus.  

PubMed

There has been dramatic change in antibiotic use in English hospitals. Data from 2004 and 2009 show that the focus on reducing fluoroquinolone and second- and third-generation cephalosporin use seems to have been heeded in NHS secondary care, and has been associated with a substantial decline in hospital Clostridium difficile rates. However, there has been a substantial increase in use of co-amoxiclav, carbapenems and piperacillin/tazobactam. In primary care, antibiotic prescribing fell markedly from 1995 to 2000, but has since risen steadily to levels seen in the early 1990s. There remains a 2-fold variation in antimicrobial prescribing among English General Practices. In 2010, the NHS Atlas of Variation documented a 3-fold variation in the prescription of quinolones and an 18-fold variation in cephalosporins by Primary Care Trusts across England. There is a clear need to improve antimicrobial prescribing. This paper describes the development of new antimicrobial stewardship programmes for primary care and hospitals by the Department of Health's Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infection: Antimicrobial Stewardship in Primary Care Initiative. The secondary care programme promotes the rapid prescription of the right antibiotic at the right dose at the right time, followed by active review for all patients still on antibiotics 48 h after admission. The five options available are to stop, switch to oral, continue and review again, change (if possible to a narrower spectrum) or move to outpatient parenteral antibiotic therapy. A range of audit and outcome tools has been developed, but to maintain optimal antimicrobial usage, monitoring of local and national quantitative and qualitative data on prescribing and consumption is required, linked to the development of key performance indicators in primary, secondary and tertiary care. PMID:22855879

Ashiru-Oredope, Diane; Sharland, Mike; Charani, Esmita; McNulty, Cliodna; Cooke, Jonathan

2012-07-01

94

Influence of hybrid inorganic/organic mesoporous and nanostructured materials on the cephalosporins' efficacy on different bacterial strains.  

PubMed

The aim of this study was to investigate the effect of different hybrid inorganic-organic micro- and nanomaterials (Fe(3)O(4)/PEG(600), Fe(3)O(4)/C(12), ZSM-5) on the antibacterial activity of different cephalosporins against Gram-positive and Gram-negative bacterial strains. The synergic effect of the studied materials was demonstrated by the increase in the growth inhibition zones diameter. All tested hybrid micro- and nanomaterials increased the activity of cefotaxime against Staphylococcus aureus. ZSM-5 increased the activity of cefotaxime and ceftriaxone and Fe(3)O(4)/C(12) that of ceftriaxone against Pseudomonas aeruginosa and S. aureus. The anti-Pseudomonas, anti-Klebsiella pneumoniae and anti-Bacillus subtilis activity of cefoperazone was increased by Fe(3)O(4)/C(12) nanoparticles, while the ZSM-5 improved its anti-Escherichia coli, K. pneumoniae, S. aureus and B. subtilis activity, whereas Fe(3)O(4)/PEG(600) against K. pneumoniae. The anti-K. pneumoniae activity of cefepime was increased by all tested nanoparticles, whereas its anti-B. subtilis and anti-E. coli activity was improved by Fe(3)O(4)/C(12) and Fe(3)O(4)/PEG(600) nanoparticles. In conclusion, both magnetic Fe(3)O(4) nanoparticles, charged outside as extra-shell with the antibiotic as well as ZSM-5 microparticles carrying the antibiotic inside the pores, significantly and specifically improved cephalosporin efficacy. A probable explanation for the increase in the antibiotic efficiency is the better penetration through the cellular wall of the antibiotic charged nanoparticles. PMID:23101869

Carmen Chifiriuc, M; Mihaiescu, D; Ilinca, E; Marutescu, L; Mihaescu, G; Mihai Grumezescu, A

2012-12-01

95

Antibiotic rotation strategies to reduce antimicrobial resistance in Gram-negative bacteria in European intensive care units: study protocol for a cluster-randomized crossover controlled trial  

PubMed Central

Background Intensive care units (ICU) are epicenters for the emergence of antibiotic-resistant Gram-negative bacteria (ARGNB) because of high rates of antibiotic usage, rapid patient turnover, immunological susceptibility of acutely ill patients, and frequent contact between healthcare workers and patients, facilitating cross-transmission. Antibiotic stewardship programs are considered important to reduce antibiotic resistance, but the effectiveness of strategies such as, for instance, antibiotic rotation, have not been determined rigorously. Interpretation of available studies on antibiotic rotation is hampered by heterogeneity in implemented strategies and suboptimal study designs. In this cluster-randomized, crossover trial the effects of two antibiotic rotation strategies, antibiotic mixing and cycling, on the prevalence of ARGNB in ICUs are determined. Antibiotic mixing aims to create maximum antibiotic heterogeneity, and cycling aims to create maximum antibiotic homogeneity during consecutive periods. Methods/Design This is an open cluster-randomized crossover study of mixing and cycling of antibiotics in eight ICUs in five European countries. During cycling (9 months) third- or fourth-generation cephalosporins, piperacillin-tazobactam and carbapenems will be rotated during consecutive 6-week periods as the primary empiric treatment in patients suspected of infection caused by Gram-negative bacteria. During mixing (9 months), the same antibiotics will be rotated for each consecutive antibiotic course. Both intervention periods will be preceded by a baseline period of 4 months. ICUs will be randomized to consecutively implement either the mixing and then cycling strategy, or vice versa. The primary outcome is the ICU prevalence of ARGNB, determined through monthly point-prevalence screening of oropharynx and perineum. Secondary outcomes are rates of acquisition of ARGNB, bacteremia and appropriateness of therapy, length of stay in the ICU and ICU mortality. Results will be adjusted for intracluster correlation, and patient- and ICU-level variables of case-mix and infection-prevention measures using advanced regression modeling. Discussion This trial will determine the effects of antibiotic mixing and cycling on the unit-wide prevalence of ARGNB in ICUs. Trial registration ClinicalTrials.gov NCT01293071 December 2010. PMID:25011604

2014-01-01

96

Bio-inspired synthesis yields a tricyclic indoline that selectively resensitizes methicillin-resistant Staphylococcus aureus (MRSA) to ?-lactam antibiotics  

PubMed Central

The continuous emergence of resistant bacteria has become a major worldwide health threat. The current development of new antibacterials has lagged far behind. To discover reagents to fight against resistant bacteria, we initiated a chemical approach by synthesizing and screening a small molecule library, reminiscent of the polycyclic indole alkaloids. Indole alkaloids are a class of structurally diverse natural products, many of which were isolated from plants that have been used as traditional medicine for millennia. Specifically, we adapted an evolutionarily conserved biosynthetic strategy and developed a concise and unified diversity synthesis pathway. Using this pathway, we synthesized 120 polycyclic indolines that contain 26 distinct skeletons and a wide variety of functional groups. A tricyclic indoline, Of1, was discovered to selectively potentiate the activity of ?-lactam antibiotics in multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA), but not in methicillin-sensitive S. aureus. In addition, we found that Of1 itself does not have antiproliferative activity but can resensitize several MRSA strains to the ?-lactam antibiotics that are widely used in the clinic, such as an extended-spectrum ?-lactam antibiotic amoxicillin/clavulanic acid and a first-generation cephalosporin cefazolin. These data suggest that Of1 is a unique selective resistance-modifying agent for ?-lactam antibiotics, and it may be further developed to fight against resistant bacteria in the clinic. PMID:24019472

Podoll, Jessica D.; Liu, Yongxiang; Chang, Le; Walls, Shane; Wang, Wei; Wang, Xiang

2013-01-01

97

Do antibiotics maintain antibiotic resistance?  

Microsoft Academic Search

Important human pathogens resistant to antibiotics result from the human use of antibiotics. Does this imply that reducing their usage or removing antibiotics from medicine and agriculture will restore the effectiveness of these drugs? The authors argue that resistance evolution and susceptibility evolution are not, in a sense, just different sides of the same coin. Resistance genes acquire new functions

Jack A. Heinemann; Robert G. Ankenbauer; Carlos F. Amábile-Cuevas

2000-01-01

98

Third-generation cephalosporin resistance in Shigella sonnei, Argentina.  

PubMed Central

Shigella sonnei resistant to cefotaxime (but not to ceftazidime) was isolated for the first time in stool samples from a pediatric patient with vomiting and bloody diarrhea in northern Argentina. Microbiologic and biochemical tests confirmed the presence of an extended spectrum beta-lactamase displaying an apparent isoelectric point value of 8.2. PMID:11384523

Radice, M.; Gonzéález, C.; Power, P.; Vidal, M. C.; Gutkind, G.

2001-01-01

99

Study of different off-line sample processing procedures and the measurement of antibiotic and antiviral levels in human serum by high-performance liquid chromatography  

Microsoft Academic Search

We attempted to devise a preparation method for clinical samples that could be used for all antibiotics and antivirals. We studied thirteen antibiotics, including five penicillins, four cephalosporins, metronidazole, ofloxacin, and sulfamethoxazole and four protease inhibitors including indinavir, retonavir, nelfinavir, and sequinavir. We compared four sample preparation techniques including solvent precipitation, filtration and resin column. We employ HPLC methods based

Paul Metz; Sue J. Kohlhepp; D. N. Gilbert

2002-01-01

100

Cephamycins, a New Family of ?-Lactam Antibiotics I. Production by Actinomycetes, Including Streptomyces lactamdurans sp. n1  

PubMed Central

A number of actinomycetes isolated from soil were found to produce one or more members of a new family of antibiotics, the cephamycins, which are structurally related to cephalosporin C. The cephamycins were produced in submerged fermentation in a wide variety of media by one or more of eight different species of Streptomyces, including a newly described species, S. lactamdurans. These antibiotics exhibit antibacterial activity against a broad spectrum of bacteria which includes many that are resistant to the cephalosporins and penicillins. PMID:4790552

Stapley, E. O.; Jackson, M.; Hernandez, S.; Zimmerman, S. B.; Currie, S. A.; Mochales, S.; Mata, J. M.; Woodruff, H. B.; Hendlin, D.

1972-01-01

101

Evolution of an Antibiotic Resistance Enzyme Constrained by Stability and Activity Trade-offs  

Microsoft Academic Search

Pressured by antibiotic use, resistance enzymes have been evolving new activities. Does such evolution have a cost? To investigate this question at the molecular level, clinically isolated mutants of the β-lactamase TEM-1 were studied. When purified, mutant enzymes had increased activity against cephalosporin antibiotics but lost both thermodynamic stability and kinetic activity against their ancestral targets, penicillins. The X-ray crystallographic

Xiaojun Wang; George Minasov; Brian K. Shoichet

2010-01-01

102

Post-Antibiotic Effects of Cefdinir on Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Streptococcus pyogenes  

Microsoft Academic Search

The post-antibiotic effects (PAEs) of a new cephalosporin, cefdinir, were determined against a range of organisms using a viable counting technique. Cefdinir exerted considerable PAEs against Staphylococcus aureus and Streptococcus pyogenes, but no overall post-antibiotic inhibition of growth was detected against Escherichia coli or Klebsiella pneumoniae. Exposure to cefdinir made the gram-negative organisms susceptible to the washing procedure used for

B. M. A. Howard; R. J. Pinney; J. T. Smith

1994-01-01

103

Antibiotic resistance.  

PubMed

Essential facts There are more than 15 different classes of antibiotics that differ in their chemical structure and their action against bacteria. An antibiotic may be effective against only one or multiple types of bacteria. Bacteria develop resistance when specific antibiotics lose their ability to kill them or stop their growth. While some bacteria are naturally immune, resistance also arises spontaneously as a result of chance mutations. As resistance is increasing and few new antibiotics are being discovered, the problem is now seen as a major public health threat. PMID:25370240

2014-11-01

104

Ro 13-9904, a long-acting broad-spectrum cephalosporin: in vitro and in vivo studies.  

PubMed Central

Ro 13-9904, a new parenteral cephalosporin, was found to have high in vitro activity against Enterobacteriaceae and other gram-negative bacteria, including various isolates resistant to cefuroxime, cefamandole, cefoxitin, and cefazolin. It showed promising activity against Pseudomonas aeruginosa. Although inhibitory against Staphylococcus aureus at concentrations readily achievable in plasma, it was less potent against this pathogen than cefamandole, cefazolin, or cefuroxime. Isolates of Streptococcus faecalis were uniformly resistant to all the cephalosporins tested. Ro 13-9904 was more active than cefotaxime against Proteus mirabilis, Neisseria gonorrhoeae, Neisseria meningitidis, and Haemophilus influenzae, but less active against S. aureus. Ro 13-9904 was stable to various types of beta-lactamases. Its therapeutic efficacy against experimental septicemias in mice was equal to or slightly superior to that of cefotaxime and SCE-1365 when the antibiotics were administered in repeated subcutaneous doses after bacterial challenge. Cefoperazone, and particularly cefamandole nafate, cefazolin, and mezlocillin were less effective. Although structurally related to cefotaxime and SCE-1365, Ro 13-9904 was found to differ from them in one important respect, namely, in having a long duration of action; this was observed with single-dose treatment given before bacterial challenge. Its broad spectrum of activity coupled with favorable pharmacokinetic properties make Ro 13-9904 a promising compound for clinical studies. PMID:6972194

Angehrn, P; Probst, P J; Reiner, R; Then, R L

1980-01-01

105

Antibiotic Safety  

MedlinePLUS

... Copyright © 2005 by The Association for Professionals in Infection Control and Epidemiology (APIC). www.apic.org How do I take antibiotics safely and effectively? Over half of the people who use ... kill bacteria, not viruses. • Take all of ...

106

?-Lactam Antibiotics  

Microsoft Academic Search

The ?-lactam antibiotics are a large class of diverse compounds used clinically in both the oral and parenteral forms. The\\u000a ?-lactam antibiotic agents have become the most widely used therapeutic class of antimicrobials because of their broad antibacterial\\u000a spectrum and excellent safety profile. Reports of drug-drug interactions with the ?-lactam antimicrobials are a relatively\\u000a rare phenomenon, and when interactions do

Melinda M. Neuhauser; Larry H. Danziger

107

Influence of substituent groups at the 3-position on the mass spectral fragmentation pathways of cephalosporins.  

PubMed

The structural fragment ions of nine cephalosporins were studied by electrospray ionization quadrapole trap mass spectrometry (Q-Trap MS(n)) in positive mode. The influence of substituent groups in the 3-position on fragmentation pathway B, an alpha-cleavage between the C7-C8 single bond, coupled with a [2,4]-trans-Diels-Alder cleavage simultaneously within the six-membered heterocyclic ring, was also investigated. It was found that when the substituent groups were methyl, chloride, vinyl, or propenyl, fragmentations belonging to pathway B were detected; however, when the substituents were heteroatoms such as O, N, or S, pathway B fragmentation was not detected. This suggested that the [M-R(3)](+) ion, which was produced by the bond cleavage within the substituent group at the 3-position, had a key influence on fragmentation pathway B. This could be attributed to the strong electronegativity of the heteroatoms (O, N, S) that favors the production of the [M-R(3)](+) ion. Moreover, having the positive charge of the [M-R(3)](+) ion localized on the nitrogen atom in the 1-position changed the electron density distribution of the heterocyclic structure, which prohibits a [2,4]-reverse-Diels-Alder fragmentation and as a result fragmentation pathway B could not occur. The influence of the substituent group in the 3-position was determined by the intensity ratio (e/d) of ions produced by fragmentation pathway A, a [2,2]-trans-Diels-Alder cleavage within the quaternary lactam ring, including the breaking of the amide bond and the C6-C7 single bond (ion d), and fragmentation pathway B (ion e). The results indicate that the electronegativity of the substituent group was a key influencing factor of pathway B fragmentation intensity, because the intensity ratio (e/d) is higher for a chlorine atom, a vinyl, or a propenyl group than that of a methyl group. This study provided some theoretical basis for the identification of cephalosporin antibiotics and structural analysis of related substances in drugs. PMID:20552707

Li, Jin; Zhang, Dou-sheng; Chong, Xiao-meng; Hu, Chang-qin

2010-07-30

108

New spectrofluorimetric method for determination of cephalosporins in pharmaceutical formulations.  

PubMed

Simple, accurate and sensitive spectrofluorimetric method has been proposed for the determination of three cephalosporins, namely; cefixime (cefi), cephalexine (ceph), cefotaxime sodium (cefo) in pharmaceutical formulations. The method is based on a reaction between cephalosporins with 1, 2-naphthoquinone-4-sulfonic (NQS) in alkaline medium, at pH values of 12.0 for cefi and 13.0 for ceph and cefo to give highly fluorescent derivatives extracted with chloroform and subsequently measured at 600,580 and 580 nm after excitation at 520,455 and 490 nm for cefi, ceph and cefo respectively. The optimum experimental conditions have been studied. Beer's law is obeyed over the concentrations of 10-35 ng/mL, 10-60 ng/mL and 20-45 ng/mL for cefi,ceph and cefo, respectively. The detection limits were 2.02 ng/mL, 2.09 ng/mL and 2.30 ng/mL for cefi, ceph and cefo, respectively, with a linear regression correlation coefficient of 0.9987, 0.9995 and 0.9991 and recoveries in range from 98.5-107.04, 95.17-101.00 and 95.00-109.55% for cefi, ceph and cefo, respectively. This method is simple and can be applied for the determination of cefi, ceph and cefo in pharmaceutical formulations in quality control laboratories. PMID:22160361

Elbashir, Abdalla A; Ahmed, Shazalia M Ali; Aboul-Enein, Hassan Y

2012-05-01

109

New spectrofluorimetric method for determination of cephalosporins in pharmaceutical formulations.  

PubMed

A simple, accurate, precise spectrofluorimetric method has been proposed for the determination of three cephalosporins, namely, cefixime (cefi), cephalexine (ceph), and cefotaxime sodium (cefo) in pharmaceutical formulations. This method is based on a reaction between cephalosporins with 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) in alkaline medium, at pH 12.0 for cefi and 13.0 for ceph and cefo to give highly fluorescent derivatives extracted with chloroform and subsequent measurements of the formed fluorescent products at 520, 500 and 510?nm after excitation at 480, 470 and 480?nm for cefi, ceph and cefo respectively. The optimum experimental conditions have been studied. Beer's law is obeyed over concentrations of 10-60?ng/mL, 5-35?ng/mL and 10-60?ng/mL for cefi, ceph and cefo, respectively. The detection limits were 4.20?ng/mL, 2.54?ng/mL and 4.09?ng/mL for cefi, ceph and cefo, respectively, with a linear regression correlation coefficient of 0.99783, 0.99705 and 0.9978 and recoveries in ranges 96.96-105.77, 96.13-102.55 and 95.45-105.39% for cefi, ceph and cefo, respectively. This method is simple and can be applied for the determination of cefi, ceph and cefo in pharmaceutical formulations in quality control laboratories. PMID:22991324

Ali Ahmed, Shazalia M; Elbashir, Abdalla A; Suliman, Fakhr Eldin O; Aboul-Enein, Hassan Y

2013-01-01

110

Antipneumococcal activity of ceftobiprole, a novel broad-spectrum cephalosporin.  

PubMed

Ceftobiprole (previously known as BAL9141), an anti-methicillin-resistant Staphylococcus aureus cephalosporin, was very highly active against a panel of 299 drug-susceptible and -resistant pneumococci, with MIC(50) and MIC(90) values (microg/ml) of 0.016 and 0.016 (penicillin susceptible), 0.06 and 0.5 (penicillin intermediate), and 0.5 and 1.0 (penicillin resistant). Ceftobiprole, imipenem, and ertapenem had lower MICs against all pneumococcal strains than amoxicillin, cefepime, ceftriaxone, cefotaxime, cefuroxime, or cefdinir. Macrolide and penicillin G MICs generally varied in parallel, whereas fluoroquinolone MICs did not correlate with penicillin or macrolide susceptibility or resistance. All strains were susceptible to linezolid, quinupristin-dalfopristin, daptomycin, vancomycin, and teicoplanin. Time-kill analyses showed that at 1x and 2x the MIC, ceftobiprole was bactericidal against 10/12 and 11/12 strains, respectively. Levofloxacin, moxifloxacin, vancomycin, and teicoplanin were each bactericidal against 10 to 12 strains at 2x the MIC. Azithromycin and clarithromycin were slowly bactericidal, and telithromycin was bactericidal against only 5/12 strains at 2x the MIC. Linezolid was mainly bacteriostatic, whereas quinupristin-dalfopristin and daptomycin showed marked killing at early time periods. Prolonged serial passage in the presence of subinhibitory concentrations of ceftobiprole failed to yield mutants with high MICs towards this cephalosporin, and single-passage selection showed very low frequencies of spontaneous mutants with breakthrough MICs towards ceftobiprole. PMID:15855516

Kosowska, Klaudia; Hoellman, Dianne B; Lin, Gengrong; Clark, Catherine; Credito, Kim; McGhee, Pamela; Dewasse, Bonifacio; Bozdogan, Bülent; Shapiro, Stuart; Appelbaum, Peter C

2005-05-01

111

Antipneumococcal Activity of Ceftobiprole, a Novel Broad-Spectrum Cephalosporin  

PubMed Central

Ceftobiprole (previously known as BAL9141), an anti-methicillin-resistant Staphylococcus aureus cephalosporin, was very highly active against a panel of 299 drug-susceptible and -resistant pneumococci, with MIC50 and MIC90 values (?g/ml) of 0.016 and 0.016 (penicillin susceptible), 0.06 and 0.5 (penicillin intermediate), and 0.5 and 1.0 (penicillin resistant). Ceftobiprole, imipenem, and ertapenem had lower MICs against all pneumococcal strains than amoxicillin, cefepime, ceftriaxone, cefotaxime, cefuroxime, or cefdinir. Macrolide and penicillin G MICs generally varied in parallel, whereas fluoroquinolone MICs did not correlate with penicillin or macrolide susceptibility or resistance. All strains were susceptible to linezolid, quinupristin-dalfopristin, daptomycin, vancomycin, and teicoplanin. Time-kill analyses showed that at 1× and 2× the MIC, ceftobiprole was bactericidal against 10/12 and 11/12 strains, respectively. Levofloxacin, moxifloxacin, vancomycin, and teicoplanin were each bactericidal against 10 to 12 strains at 2× the MIC. Azithromycin and clarithromycin were slowly bactericidal, and telithromycin was bactericidal against only 5/12 strains at 2× the MIC. Linezolid was mainly bacteriostatic, whereas quinupristin-dalfopristin and daptomycin showed marked killing at early time periods. Prolonged serial passage in the presence of subinhibitory concentrations of ceftobiprole failed to yield mutants with high MICs towards this cephalosporin, and single-passage selection showed very low frequencies of spontaneous mutants with breakthrough MICs towards ceftobiprole. PMID:15855516

Kosowska, Klaudia; Hoellman, Dianne B.; Lin, Gengrong; Clark, Catherine; Credito, Kim; McGhee, Pamela; Dewasse, Bonifacio; Bozdogan, Bulent; Shapiro, Stuart; Appelbaum, Peter C.

2005-01-01

112

Bactericidal Activity against Cephalosporin-ResistantStreptococcus pneumoniaein Cerebrospinal Fluid of Children with Acute Bacterial Meningitis  

Microsoft Academic Search

There are reports of failure of extended-spectrum cephalosporin treatment in pneumococcal meningitis. On the basis of in vitro and animal experimental studies, the addition of vancomycin or rifampin to an extended- spectrum cephalosporin has been recommended for empiric treatment of these patients. Cerebrospinal fluid (CSF) was taken from 31 children with bacterial meningitis randomized to receive ceftriaxone alone (n 511),

KEITH P. KLUGMAN; IAN R. FRIEDLAND; ANDJOHN S. BRADLEY

113

Thin Layer Chromatographic Analysis of Beta-Lactam Antibiotics  

PubMed Central

Purpose: The paper describes some thin layer chromatographic procedures that allow simple and rapid separation and identification of penicillins and cephalosporins from complex mixtures. Methods: Using silicagel GF254 as stationary phase and selecting different mobile phases we succeeded in the separation of the studied beta-lactamins. Our aim was not only to develop a simple, rapid and efficient method for their separation but also the optimization of the analytical conditions. Results: No system will separate all the beta-lactams, but they could be identified when supplementary information is used from color reactions and/or by using additional chromatographic systems. Conclusions: The right combination of solvent system and detection method allows the identification of the studied penicillins and cephalosporins and can be successfully used in the preliminary analysis beta-lactam antibiotics. Conclusion: The right combination of solvent system and detection method allows the identification of the studied penicillins and cephalosporins and can be successfully used in the preliminary analysis beta-lactam antibiotics. PMID:24312862

Hancu, Gabriel; Simon, Brigitta; Kelemen, Hajnal; Rusu, Aura; Mircia, Eleonora; Gyeresi, Arpad

2013-01-01

114

Retrospective analysis of antibiotic resistance pattern to urinary pathogens in a Tertiary Care Hospital in South India  

PubMed Central

Context: The distribution of uropathogens and their susceptibility pattern to antibiotics vary regionally and even in the same region, they change over time. Therefore, the knowledge on the frequency of the causative microorganisms and their susceptibility to various antibiotics are necessary for a better therapeutic outcome. Aim: The aim was to study the frequency and distribution of uropathogens and their resistance pattern to antibiotics in a tertiary care hospital. Settings and Design: Retrospective study for a period of 1 year from January 2011 to December 2011 in a tertiary care hospital. Materials and Methods: The culture and sensitivity data of the uropathogens from suspected cases of UTI were collected from the records of Microbiology Department for study period. Midstream urine samples were processed for microscopy and culture, and the organisms were identified by standard methods. Antibiotic susceptibility was carried out by Kirby-Bauer disk diffusion method according to Clinical and Laboratory Standards Institute guidelines. Descriptive statistics were used to analyze the data. Results: Of 896 urine samples, 348 (38.84%) samples were positive for urine culture. Escherichia coli (52.59%) was the most common organism followed by Klebsiella. E. coli was least resistant to imipenem (8%) and amikacin (16%) and was highly resistant to co-trimoxazole (69%) and ampicillin (86%). Klebsiella species were least resistant to amikacin (26%) and were highly resistant to ampicillin (92%). The overall resistance pattern of antibiotics to uropathogens was the highest to nalidixic acid (79%) followed by co-trimoxazole (75%) and ampicillin (72%). Good susceptibility was seen with imipenem and cephalosporins. Conclusion: E. coli is still the most common uropathogen. Nalidixic acid, ampicillin, co-trimoxazole, and first-generation fluoroquinolones have limited value for the treatment of UTI. Sensitivity to imipenem and amikacin are still retained and may be prescribed for complicated UTI. Routine monitoring of drug resistance pattern will help to identify the resistance trends regionally. This will help in the empirical treatment of UTIs to the clinicians.

Somashekara, Saligrama Chikkannasetty; Deepalaxmi, Salmani; Jagannath, Narumalla; Ramesh, Bannaravuri; Laveesh, Madathil Ravindran; Govindadas, Damodaram

2014-01-01

115

Reverse phase high speed liquid chromatography of antibiotics. II. Use of high efficiency small particle columns.  

PubMed

Improved methods for the separation and quantitation of cephalosporins, penicillins, tetracyclines and several miscellaneous antibiotics by reverse phase high speed liquid chromatography are presented. The methods have been improved significantly by the substitution of high efficiency, small particle (approximately 10 micrometer reverse phase columns in place of the previously used medium efficiency, pellicular columns. The conditions and procedures described here illustrate that considerable improvements in separation and sensitivity of detection of antibiotics are achieved. Pure compounds, complex mixtures of antibiotics in a variety of dosage forms and fermentation broths are routinely analyzed by the described procedures. PMID:591445

White, E R; Carroll, M A; Zarembo, J E

1977-10-01

116

Genetic Manipulation of Antibiotic-Producing Microorganisms  

Microsoft Academic Search

The application of directed selection techniques and genetic engineering methods for manipulation of antibiotic-producing microorganisms is generating a new era in industrial microbiology. Modern methods, based on advances in the knowledge of the biosynthetic pathways and regulatory mechanisms involved in the induction and repression of genes involved in antibiotic synthesis, provide a means of increasing antibiotic activity. Hence, recombinant DNA

John N. Vournakis; Richard P. Elander

1983-01-01

117

Identification and Evaluation of Improved 4?-O-(Alkyl) 4,5-Disubstituted 2-Deoxystreptamines as Next-Generation Aminoglycoside Antibiotics  

PubMed Central

ABSTRACT The emerging epidemic of drug resistance places the development of efficacious and safe antibiotics in the spotlight of current research. Here, we report the design of next-generation aminoglycosides. Discovery efforts were driven by rational synthesis focusing on 4? alkylations of the aminoglycoside paromomycin, with the goal to alleviate the most severe and disabling side effect of aminoglycosides—irreversible hearing loss. Compounds were evaluated for target activity in in vitro ribosomal translation assays, antibacterial potency against selected pathogens, cytotoxicity against mammalian cells, and in vivo ototoxicity. The results of this study produced potent compounds with excellent selectivity at the ribosomal target, promising antibacterial activity, and little, if any, ototoxicity upon chronic administration. The favorable biocompatibility profile combined with the promising antibacterial activity emphasizes the potential of next-generation aminoglycosides in the treatment of infectious diseases without the risk of ototoxicity. PMID:25271289

Duscha, Stefan; Boukari, Heithem; Shcherbakov, Dimitri; Salian, Sumantha; Silva, Sandrina; Kendall, Ann; Kato, Takayuki; Akbergenov, Rashid; Perez-Fernandez, Deborah; Bernet, Bruno; Vaddi, Swapna; Thommes, Pia; Schacht, Jochen; Crich, David; Bottger, Erik C.

2014-01-01

118

Combating Antibiotic Resistance  

NSDL National Science Digital Library

In the past few years, there have been more reports of bacteria that are increasingly resilient to antibiotics. Understandably, this antibiotic resistance is of great concern to the medical community in terms of public health, and is due largely to the increased use of antibiotics. With this in mind, the United States Food and Drug Administration has developed this Web site to inform the general public about this phenomenon, as well as to provide a number of documents generated by different government agencies about this problem and strategies for combating it. For those unacquainted with the situation, there are several helpful general fact sheets and overviews provided online from the Center for Disease Control and the University of Wisconsin. Additionally, the site contains several papers outlining some general recommendations about how the problem can be contained with the cooperation of doctors, hospitals, and increased awareness of the populace.

2007-03-16

119

FDA: Antibiotic Resistance  

NSDL National Science Digital Library

In the past few years, there have been more reports of bacteria that are increasingly resilient to antibiotics. Understandably, this antibiotic resistance is of great concern to the medical community in terms of public health, and is due largely to the increased use of antibiotics. With this in mind, the United States Food and Drug Administration has developed this Web site to inform the general public about this phenomenon, as well as to provide a number of documents generated by different government agencies about this problem and strategies for combating it. For those unacquainted with the situation, there are several helpful general fact sheets and overviews provided online from the Center for Disease Control and the University of Wisconsin. Additionally, the site contains several papers outlining some general recommendations about how the problem can be contained with the cooperation of doctors, hospitals, and increased awareness of the populace.

2001-01-01

120

Generation of a safety enhanced Salmonella Gallinarum ghost using antibiotic resistance free plasmid and its potential as an effective inactivated vaccine candidate against fowl typhoid.  

PubMed

A safety enhanced Salmonella Gallinarum (SG) ghost was constructed using an antibiotic resistance gene free plasmid and evaluated its potential as fowl typhoid (FT) vaccine candidate. The antibiotic resistance free pYA3342 plasmid possesses aspartate semialdehyde dehydrogenase gene which is complimentary to the deletion of the chromosomal asd gene in the bacterial host. This plasmid was incorporated with a ghost cassette containing the bacteriophage PhiX174 lysis gene E, designated as pJHL101. The plasmid pJHL101 was transformed into a two virulence genes-deleted SG. The SG ghosts with tunnel formation and loss of cytoplasmic contents were observed by scanning electron microscopy and transmission electron microscopy. The cell viability of the culture solution was decreased to 0% at 24h after the induction of gene E expression by an increase in temperature from 37°C to 42°C. The safety and protective efficacy of the SG ghost vaccine was further examined in chickens which were divided into three groups: group A (non-immunized control), group B (orally immunized), and group C (intramuscularly immunized). The birds were immunized at 7d of age. No clinical symptoms associated with FT such as anorexia, depression and greenish diarrhea were observed in the immunized chickens. Upon challenge with a virulent SG strain at 3 week post-immunization, the chickens immunized with the SG ghost via various routes were efficiently protected, as shown by significantly lower mortality and post-mortem lesions in comparison with control group. In addition, all the immunized chickens showed significantly higher antibody responses accompanied by a potent antigen-specific lymphocyte proliferative response along with significantly increased numbers of CD4? and CD8? T lymphocytes. Overall, our results provide a promising approach of generating SG ghosts using the antibiotic resistance free plasmid in order to prepare a non-living bacterial vaccine candidate which could be environmentally safe yet efficient to prevent FT in chickens. PMID:24406393

Jawale, Chetan V; Chaudhari, Atul A; Lee, John Hwa

2014-02-19

121

Novel cephalosporins for the treatment of MRSA infections.  

PubMed

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are among the most difficult to treat, Efforts toward the development of cephalosporin antimicrobial agents with activity against MRSA have been ongoing for the last decade. In spite of advancement of several potential drugs into clinical trials no such drugs are available for anti-MRSA therapy yet. The recent emergence of MRSA strains resistant to vancomycin, which is the treatment of choice for MRSA infection, has made the clinical need for new effective drugs even more pressing. In the present review structure-activity relationships are discussed with an emphasis on anti-MRSA activity, pharmacokinetics and efficacy in animal models. Clinical trial status of promising drug candidates is also provided where available. PMID:12020048

Glinka, Tomasz W

2002-02-01

122

Antibiotic resistance  

Microsoft Academic Search

If there were no antibiotic resistance, there would little need for microbiology laboratories. Faced with a patient who has a community-acquired or hospital-acquired infection, the doctor must guess the diagnosis, the likely organisms and the likely sensitivity of these bacteria. If Staphylococcus is grown from a blood culture, there is now a likelihood of more than 50% that it will

Geoff Scott

2005-01-01

123

In vitro and in vivo activities of SCE-2787, a new parenteral cephalosporin with a broad antibacterial spectrum.  

PubMed Central

SCE-2787, a new cephalosporin having a condensed azolium moiety in the 3 position and an aminothiadiazolyl group in the 7 beta side chain, was evaluated for its in vitro and in vivo activities in comparison with those of ceftazidime, flomoxef, cefpirome, and E1040. Against methicillin-susceptible strains of Staphylococcus aureus and Staphylococcus epidermidis, SCE-2787 was more active than ceftazidime and E1040 and was as active as flomoxef and cefpirome, with MICs for 90% of strains tested (MIC90s) being 1.56 micrograms/ml or less. SCE-2787 was also active against Pseudomonas aeruginosa, for which the MIC90 was 6.25 micrograms/ml, which was lower than that of cefpirome and comparable to that of ceftazidime. SCE-2787 was marginally active against methicillin-resistant strains of staphylococci and Enterococcus faecalis, although its MIC90s were the lowest among those of the antibiotics tested. The activities of SCE-2787 against Streptococcus species, most members of the family Enterobacteriaceae, and Haemophilus influenzae exceeded those of ceftazidime and flomoxef and were comparable to those of cefpirome. Furthermore, MIC90s of SCE-2787 were significantly lower than those of ceftazidime for ceftazidime-resistant isolates of Citrobacter freundii and Enterobacter cloacae. SCE-2787 was resistant to hydrolysis by various types of beta-lactamases, including the Bush group 1 beta-lactamases, and had low affinities for these enzymes, with Km or Ki values of greater than 100 microM. The in vitro activity of SCE-2787 was reflected in its efficacy in mouse protection tests. Thus, SCE-2787 appears to be a promising cephalosporin that should be further evaluated in clinical trials. PMID:1510428

Iwahi, T; Okonogi, K; Yamazaki, T; Shiki, S; Kondo, M; Miyake, A; Imada, A

1992-01-01

124

Evaluation of cephalosporins/cephamycins with antianaerobic activity by integrating microbiologic and pharmacokinetic properties.  

PubMed

When evaluating antimicrobial agents, in vitro microbiologic activity and pharmacokinetics are important factors, but these data are usually not assessed simultaneously. The purpose of the study was to compare cefoxitin, cefotetan, ceftizoxime, cefotaxime (CT), desacetylcefotaxime (DACT), and CT/DACT (1:1 ratio) by integrating their microbiologic activity against clinical isolates of Bacteroides fragilis with their pharmacokinetic properties. Minimal inhibitory concentrations (MIC) were determined by the agar dilution method. Steady-state serum concentration--time profiles were simulated for 2-gm doses in a 70-kg patient using ADAPT software and pharmacokinetic data from published studies. Serum protein binding (%) of each agent was also obtained from published studies and used to calculate the unbound serum concentration--time profiles. As estimates of pharmacodynamic activity, time below the MIC (T less than MIC) and percentage of the dosing interval below the MIC (% INT less than MIC) were calculated for individual isolates using total and unbound serum concentrations. Data analysis included MIC50, MIC90, range, breakpoint susceptibility, and analysis of variance for T less than MIC and % INT less than MIC (Scheffé post-hoc test, P less than 0.05). The MIC90 of cefotetan was at least a twofold dilution lower than the other agents. However, using unbound (pharmacologically active) serum concentrations, T less than MIC and % INT less than MIC for ceftizoxime (at a simulated eight-hour dosing interval) were significantly smaller than with the other antibiotic regimens. Integration of in vitro and pharmacokinetic data may provide additional information to assist in the evaluation of antimicrobials. For B fragilis from our institution, the pharmacodynamic profile of unbound ceftizoxime is superior to the other antianaerobic cephalosporins/cephamycins tested. PMID:1799917

Kays, M B; White, R L; Friedrich, L V; Del Bene, V E

1991-01-01

125

Comparative in vitro evaluation of cefpimizole (U-63196E), a new antipseudomonal cephalosporin.  

PubMed Central

The activity of cefpimizole (formerly U-63196E) was compared with that of other broad-spectrum cephalosporins and penicillins. Overall, cefpimizole exhibited limited activity against gram-positive cocci and members of the family Enterobacteriaceae as compared with the other cephalosporins tested. The activity of cefpimizole against Pseudomonas aeruginosa was similar to that of cefoperazone and mezlocillin (90% MIC, 32 micrograms/ml) but poorer than that of ceftazidime (90% MIC, 8 micrograms/ml). Cefpimizole appears to have no in vitro advantage over the cephalosporins with which it was compared. PMID:3929676

LeFrock, J L; Smith, B R; Bihl, J

1985-01-01

126

Reverse phase high speed liquid chromatography of antibiotics.  

PubMed

Reverse phase high speed liquid chromatographic methods are presented for the separation and detection of cephalosporins, penicillins, tetracyclines and other miscellaneous antibiotics. The reverse phase approach is superior to ion-exchange liquid chromatography and spectrophotometric, chemical and microbiological procedures currently in use. In addition to being simple and easy to control, the technique is rapid, convenient and precise and provides the basis for the direct analysis of pure compounds, stability samples, complex mixtures and dosage forms of all types. Preparative chromatography has been used in our laboratory for the separation and isolation of up to 500 mg of antibiotics. Using this approach, we have separated and isolated small impurities as well as pure feference compounds. The methodology reported here can be extensively applied to the separation, quantitation and isolation of both naturally occurring and synthetically produced antibiotics in a variety of media including physiological fluids. PMID:1126874

White, E R; Carroll, M A; Zarembo, J E; Bender, A D

1975-03-01

127

Cefdinir: an oral cephalosporin for the treatment of respiratory tract infections and skin and skin structure infections.  

PubMed

Cefdinir is an oral third-generation cephalosporin (also known as an advanced-spectrum or generation cephem) with good in vitro activity against the pathogens responsible for community-acquired respiratory tract infections and uncomplicated skin and skin structure infections. The drug distributes very well in respiratory tract tissues and fluids, as well as skin blisters and ear fluids; its pharmacokinetic profile allows once- or twice-daily administration. Oral cefdinir 300 mg twice daily or 600 mg once daily in adults and adolescents, or 14 mg/kg/day in one or two daily doses in pediatric patients, administered for 5 or 10 days, has shown good clinical and bacteriological efficacy, at least equivalent to that of other oral agents in randomized controlled trials conducted in patients with community-acquired pneumonia, acute bacterial exacerbation of chronic bronchitis, sinusitis, acute otitis media, pharyngitis and uncomplicated skin and skin structure infections. Cefdinir is well tolerated and the oral suspension has shown superior taste or palatability over other comparator oral antimicrobial agents. Thus, cefdinir continues to represent an important cephalosporin option for the treatment of adult, adolescent and pediatric patients with mild or moderate respiratory tract or cutaneous infections, especially in areas with elevated rates of beta-lactamase production in Haemophilus influenzae and where resistance to other commonly used agents has emerged (e.g., macrolides, penicillins, tetracyclines, fluoroquinolones and trimethoprim-sulfamethoxazole). PMID:17266451

Sader, Helio S; Jones, Ronald N

2007-02-01

128

Antibiotics Use and Mis-use Antibiotics -  

E-print Network

Antibiotics ­ Use and Mis-use Antibiotics - Use and Misuse Karen Macsween #12;Risk factors for C.difficile · Antibiotics · age · Prolonged hospital stay · GI surgery · ITU · Enteral feeding · Immunosuppressant drugs%) Kissule et al 2008 J Hosp Med 3: 64 #12;In-patient antibiotic misuse · Nature of patients ­ acutely ill

Glasgow, University of

129

77 FR 735 - New Animal Drugs; Cephalosporin Drugs; Extralabel Animal Drug Use; Order of Prohibition  

Federal Register 2010, 2011, 2012, 2013

...FDA-2008-N-0326] New Animal Drugs; Cephalosporin Drugs...lactamases in Bacteria of Animal Origin. Veterinary Microbiology...Typhimurium Isolated from Food Animals. Microbial Drug Resistance...Antimicrobial Susceptibility Testing: Sixteenth Informational...

2012-01-06

130

Evidence for Induction of Integron-Based Antibiotic Resistance by the SOS Response in a Clinical Setting  

PubMed Central

Bacterial resistance to ?-lactams may rely on acquired ?-lactamases encoded by class 1 integron-borne genes. Rearrangement of integron cassette arrays is mediated by the integrase IntI1. It has been previously established that integrase expression can be activated by the SOS response in vitro, leading to speculation that this is an important clinical mechanism of acquiring resistance. Here we report the first in vivo evidence of the impact of SOS response activated by the antibiotic treatment given to a patient and its output in terms of resistance development. We identified a new mechanism of modulation of antibiotic resistance in integrons, based on the insertion of a genetic element, the gcuF1 cassette, upstream of the integron-borne cassette blaOXA-28 encoding an extended spectrum ?-lactamase. This insertion creates the fused protein GCUF1-OXA-28 and modulates the transcription, the translation, and the secretion of the ?-lactamase in a Pseudomonas aeruginosa isolate (S-Pae) susceptible to the third generation cephalosporin ceftazidime. We found that the metronidazole, not an anti-pseudomonal antibiotic given to the first patient infected with S-Pae, triggered the SOS response that subsequently activated the integrase IntI1 expression. This resulted in the rearrangement of the integron gene cassette array, through excision of the gcuF1 cassette, and the full expression the ?-lactamase in an isolate (R-Pae) highly resistant to ceftazidime, which further spread to other patients within our hospital. Our results demonstrate that in human hosts, the antibiotic-induced SOS response in pathogens could play a pivotal role in adaptation process of the bacteria. PMID:22719259

Hocquet, Didier; Llanes, Catherine; Thouverez, Michelle; Kulasekara, Hemantha D.; Bertrand, Xavier; Plesiat, Patrick; Mazel, Didier; Miller, Samuel I.

2012-01-01

131

Antibiotic-Resistant Fecal Bacteria, Antibiotics, and Mercury in Surface Waters of Oakland County, Michigan, 2005-2006  

USGS Publications Warehouse

Water samples collected from 20 stream sites in Oakland and Macomb Counties, Mich., were analyzed to learn more about the occurrence of cephalosporin-resistant Escherichia coli (E. coli) and vancomycin-resistant enterococci (VRE) and the co-occurrence of antibiotics and mercury in area streams. Fecal indicator bacteria concentrations exceeded the Michigan recreational water-quality standard of 300 E. coli colony-forming units (CFU) per 100 milliliters of water in 19 of 35 stream-water samples collected in Oakland County. A gene commonly associated with enterococci from humans was detected in samples from Paint Creek at Rochester and Evans Ditch at Southfield, indicating that human fecal waste is a possible source of fecal contamination at these sites. E. coli resistant to the cephalosporin antibiotics (cefoxitin and/or ceftriaxone) were found at all sites on at least one occasion. The highest percentages of E. coli isolates resistant to cefoxitin and ceftriaxone were 71 percent (Clinton River at Auburn Hills) and 19 percent (Sashabaw Creek near Drayton Plains), respectively. Cephalosporin-resistant E. coli was detected more frequently in samples from intensively urbanized or industrialized areas than in samples from less urbanized areas. VRE were not detected in any sample collected in this study. Multiple antibiotics (azithromycin, erythromycin, ofloxacin, sulfamethoxazole, and trimethoprim) were detected in water samples from the Clinton River at Auburn Hills, and tylosin (an antibiotic used in veterinary medicine and livestock production that belongs to the macrolide group, along with erythromycin) was detected in one water sample from Paint Creek at Rochester. Concentrations of total mercury were as high as 19.8 nanograms per liter (Evans Ditch at Southfield). There was no relation among percentage of antibiotic-resistant bacteria and measured concentrations of antibiotics or mercury in the water. Genetic elements capable of exchanging multiple antibiotic-resistance genes (class I integrons) were detected in several samples, indicating that the resistance carried by these organisms may be transferable to other bacteria, including disease-causing bacteria.

Fogarty, Lisa R.; Duris, Joseph W.; Crowley, Suzanne L.; Hardigan, Nicole

2007-01-01

132

How Antibiotics Work  

NSDL National Science Digital Library

Students are introduced to a challenge question. Towards answering the question, they generate ideas for what they need to know about medicines and how they move through our bodies, watch a few short videos to gain multiple perspectives, and then learn lecture material to obtain a basic understanding of how antibiotics kill bacteria in the human body. They learn why different forms of medicine (pill, liquid or shot) get into the blood stream at different speeds.

Vu Bioengineering Ret Program

133

Contribution of Gene Amplification to Evolution of Increased Antibiotic Resistance in Salmonella typhimurium  

Microsoft Academic Search

Abstract The use of ß-lactam antibiotics has led to the evolution and global spread of a variety of resistance mechanisms -- including ß-lactamases, a group of enzymes that degrade the ß- lactam ring. The evolution of increased ß-lactam resistance was studied by exposing independent lineages of Salmonella typhimuriumto progressive increases in cephalosporin concentration. Each lineage carried a ß-lactamase gene (blaTEM-1)

Song Sun; Otto G. Berg; John R. Roth; Dan I. Andersson

2009-01-01

134

Interstitial concentration of antibiotics and their significance for an adequate dosage  

Microsoft Academic Search

Summary The pharmacokinetic characteristics of the parenteral cephalosporins cephalothin, cefazolin, cephradine, cefamandole, cefuroxime and cefotaxime (HR-756) were compared applying six different pharmacokinetic points of view. In interpreting antibiotic concentrations measured in soft tissue interstitial fluid (STIF), special attention was paid to the following parameters: cross-point; serum to STIF (AUC) ratio before and after cross-point; STIF half-life time (T 1\\/2); half-life

H.-U. Eickenberg

1980-01-01

135

Impact of bloodstream infections on outcome and the influence of prophylactic oral antibiotic regimens in allogeneic hematopoietic SCT recipients.  

PubMed

This study aimed to determine the impact of blood stream infections (BSIs) on outcome of allogeneic hematopoietic SCT (HSCT), and to examine the influence of old (non-levofloxacin-containing) and new (levofloxacin-based) prophylactic antibiotic protocols on the pattern of BSIs. We retrospectively enrolled 246 allogeneic HSCT recipients between January 1999 and June 2006, dividing patients into BSI (within 6 months post-HSCT, n=61) and non-BSI groups (n=185). We found that Gram-negative bacteria (GNB) predominated BSI pathogens (54%). Multivariate analyses showed that patients with a BSI, compared with those without, had a significantly greater 6-month mortality (hazard ratio, 1.75; 95% confidence interval, 1.09-2.82; P=0.021) and a significantly increased length of hospital (LOH) stay (70.8 vs 55.2 days, P=0.014). Moreover, recipients of old and new protocols did not have a significantly different 6-month mortality and time-to-occurrence of BSIs. However, there were significantly more resistant GNB to third-generation cephalosporins and carbapenem in recipients of levofloxacin-based prophylaxis. Our data suggest that BSIs occur substantially and impact negatively on the outcome and LOH stay after allogeneic HSCT despite antibiotic prophylaxis. Levofloxacin-based prophylaxis, albeit providing similar efficacy to non-levofloxacin-containing regimens, may be associated with increased antimicrobial resistance. PMID:21113186

Liu, C-Y; Lai, Y-C; Huang, L-J; Yang, Y-W; Chen, T-L; Hsiao, L-T; Liu, J-H; Gau, J-P; Chen, P-M; Tzeng, C-H; Chiou, T-J

2011-09-01

136

Preparation and Properties of a Cephalosporin Acetylesterase Adsorbed onto Bentonite  

PubMed Central

A cephalosporin acetylesterase produced by Bacillus subtilis was immobilized by adsorption onto bentonite. The immobilized enzyme (EI) and the soluble enzyme (ES) exhibited Michaelis-Menton kinetics with 7-aminocephalosporanic acid (7-ACA): Km = 2.8 × 10?3 M and Km = 3.2 × 10?3 M, respectively. Similar kinetics were observed with 7-(thiophene-2-acetamido)cephalosporanic acid (cephalothin), but the Km value measured with EI (3.7 × 10?3 M) was less than one-half that measured with this substrate and ES. The reduction in Km value was correlated with the ability of bentonite to adsorb cephalothin. The reaction products, acetate and deacetyl-7-ACA, were weak competitive inhibitors of ES and EI. The Ki values for EI were 5.0 × 10?2 M for acetate and 3.6 × 10?2 M for deacetyl-7-ACA. Similar values were measured with ES and these substrates. EI retained about 80% of its initial activity after 3 weeks of storage in solution at 25 C. However, the enzyme dissociated from the bentonite particles during the deacetylation reaction. This dissociation was minimized by cross-linking EI with glutaraldehyde or bis-dimethyladipimidate, or by adding Al(OH)3 to the suspension. With the latter addition, EI was stabilized so that it could be reused nine times before one-half of the initial activity was lost. PMID:241288

Abbott, Bernard J.; Fukuda, D. S.

1975-01-01

137

[Pharmacokinetic study of a cephalosporin, cefoperazone, in liver failure].  

PubMed

The pharmacokinetics of cefoperazone, a semi-synthetic cephalosporin for parenteral use with a spectrum covering P. aeruginosa, E. cloacae, indole-positive Proteus and S. Marcescens, was studied after a 2-h intravenous infusion of 2 g of the drug in 6 patients with moderate liver function impairment (viral hepatitis in 4 cases, alcoholic fatty liver and cirrhosis in 2 cases). At the end of the infusion, mean serum concentrations (determined by a bioassay) were 208 microgram/ml in the patients and 134 microgram/ml in healthy volunteers. The half-life was 4.3 h in patients and 1.6 h in healthy volunteers. Volume of distribution and renal clearance were similar in the two groups. Extrarenal clearance of cefoperazone was lower in the patients (7.3 ml/min) than in the control group (59.4 mg/min). Urinary excretion of biologically active drug was markedly increased in the patients (79% of the dose) compared with healthy volunteers (24%). This study provides evidence that liver function impairment increases with both the apparent half-life of elimination and the urinary excretion of the drug. The results raise the question of the desirability of cefoperazone dosage adjustment in patients with hepatic diseases. PMID:6453423

Belaieff, J; Cochet, B; Allaz, A F; Rudhardt, M; Balant, L; Fabre, J

1981-04-01

138

Bactericidal activity of oral ?-lactam antibiotics in plasma and urine versus isogenic Escherichia coli strains producing broad- and extended-spectrum ?-lactamases  

Microsoft Academic Search

Bacteria harbouring extended-spectrum ?-lactamases (ESBLs), derived by mutation from TEM-1, TEM-2 or SHV-1 ?-lactamases, have been described world-wide. The in vitro activities of these enzymes against ?-lactam antibiotics, including oral cephalosporins, are well recognised. The aim of this investigation was to assess the bactericidal activity of oral ?-lactam antibiotics available in Croatia (amoxicillin\\/clavulanate, cephalexin, cefuroxime, cefadroxil and ceftibuten), in biological

Branka Bedenic; Jasmina Vranes; Sandra Suto; Zivojin Zagar

2005-01-01

139

Nutritional control of antibiotic resistance via an interface between the phosphotransferase system and a two-component signaling system.  

PubMed

Enterococci are ubiquitous inhabitants of the gastrointestinal (GI) tract. However, antibiotic-resistant enterococci are also major causes of hospital-acquired infections. Enterococci are intrinsically resistant to cephalosporins, enabling growth to abnormally high densities in the GI tract in patients during cephalosporin therapy, thereby promoting dissemination to other sites where they cause infection. Despite its importance, many questions about the underlying basis for cephalosporin resistance remain. A specific two-component signaling system, composed of the CroS sensor kinase and its cognate response regulator (CroR), is required for cephalosporin resistance in Enterococcus faecalis, but little is known about the factors that control this signaling system to modulate resistance. To explore the signaling network in which CroR participates to influence cephalosporin resistance, we employed a protein fragment complementation assay to detect protein-protein interactions in E. faecalis cells, revealing a previously unknown association of CroR with the HPr protein of the phosphotransferase system (PTS) responsible for carbohydrate uptake and catabolite control of gene expression. Genetic and physiological analyses indicate that association with HPr restricts the ability of CroR to promote cephalosporin resistance and gene expression in a nutrient-dependent manner. Mutational analysis suggests that the interface used by HPr to associate with CroR is distinct from the interface used to associate with other cellular partners. Our results define a physical and functional connection between a critical nutrient-responsive signaling system (the PTS) and a two-component signaling system that drives antibiotic resistance in E. faecalis, and they suggest a general strategy by which bacteria can integrate their nutritional status with diverse environmental stimuli. PMID:24277024

Snyder, Holly; Kellogg, Stephanie L; Skarda, Laura M; Little, Jaime L; Kristich, Christopher J

2014-01-01

140

Risk factors and treatment outcomes of bloodstream infection caused by extended-spectrum cephalosporin-resistant Enterobacter species in adults with cancer.  

PubMed

Treatment of Enterobacter infection is complicated due to its intrinsic resistance to cephalosporins. Medical records of 192 adults with cancer who had Enterobacter bacteremia were analyzed retrospectively to evaluate the risk factors for and the treatment outcomes in extended-spectrum cephalosporin (ESC)-resistant Enterobacter bacteremia in adults with cancer. The main outcome measure was 30-day mortality. Of the 192 patients, 53 (27.6%) had bloodstream infections caused by ESC-resistant Enterobacter species. Recent use of a third-generation cephalosporin, older age, tumor progression at last evaluation, recent surgery, and nosocomial acquisition were associated with ESC-resistant Enterobacter bacteremia. The 30-day mortality rate was significantly higher in the resistant group. Multivariate analysis showed that respiratory tract infection, tumor progression, septic shock at presentation, Enterobacter aerogenes as the culprit pathogen, and diabetes mellitus were independent risk factors for mortality. ESC resistance was significantly associated with mortality in patients with E. aerogenes bacteremia, although not in the overall patient population. PMID:24321352

Huh, Kyungmin; Kang, Cheol-In; Kim, Jungok; Cho, Sun Young; Ha, Young Eun; Joo, Eun-Jeong; Chung, Doo Ryeon; Lee, Nam Yong; Peck, Kyong Ran; Song, Jae-Hoon

2014-02-01

141

Antistaphylococcal Activity of Ceftobiprole, a New Broad-Spectrum Cephalosporin  

PubMed Central

Ceftobiprole (formerly BAL9141), the active component of the prodrug BAL5788 (ceftobiprole medocaril), is a novel cephalosporin with expanded activity against gram-positive bacteria. Among 152 Staphylococcus aureus isolates, including 5 vancomycin-intermediate and 2 vancomycin-resistant strains, MIC50 and MIC90 values for ceftobiprole were each 0.5 ?g/ml against methicillin-susceptible strains and 2 ?g/ml against methicillin-resistant strains. Against 151 coagulase-negative staphylococci (including 4 vancomycin-intermediate strains), MIC50 and MIC90 values were, respectively, 0.125 ?g/ml and 1 ?g/ml against methicillin-susceptible and 1 ?g/ml and 2 ?g/ml against methicillin-resistant strains. Teicoplanin was less active than vancomycin against coagulase-negative strains. Linezolid, quinupristin-dalfopristin, and daptomycin were active against all strains, whereas increased MICs for amoxicillin-clavulanate, cefazolin, minocycline, gentamicin, trimethoprim-sulfamethoxazole, levofloxacin, rifampin, mupirocin, fusidic acid, and fosfomycin were sometimes observed. At 2× MIC, ceftobiprole was bactericidal against 11 of 12 test strains by 24 h. Prolonged serial passage in the presence of subinhibitory concentrations of ceftobiprole failed to select for clones with MICs >4 times those of the parents; the maximum MIC achieved for ceftobiprole after 50 passages (in 1 of 10 strains) was 8 ?g/ml. Single-passage selections showed very low frequencies of resistance to ceftobiprole irrespective of genotype or phenotype; the maximal ceftobiprole MIC of recovered clones was 8 ?g/ml. PMID:16189100

Bogdanovich, Tatiana; Ednie, Lois M.; Shapiro, Stuart; Appelbaum, Peter C.

2005-01-01

142

Microbiological effects of sublethal levels of antibiotics.  

PubMed

The widespread use of antibiotics results in the generation of antibiotic concentration gradients in humans, livestock and the environment. Thus, bacteria are frequently exposed to non-lethal (that is, subinhibitory) concentrations of drugs, and recent evidence suggests that this is likely to have an important role in the evolution of antibiotic resistance. In this Review, we discuss the ecology of antibiotics and the ability of subinhibitory concentrations to select for bacterial resistance. We also consider the effects of low-level drug exposure on bacterial physiology, including the generation of genetic and phenotypic variability, as well as the ability of antibiotics to function as signalling molecules. Together, these effects accelerate the emergence and spread of antibiotic-resistant bacteria among humans and animals. PMID:24861036

Andersson, Dan I; Hughes, Diarmaid

2014-07-01

143

Antibiotic sensitivity pattern and cost-effectiveness analysis of antibiotic therapy in an Indian tertiary care teaching hospital  

PubMed Central

Objective: The purpose of this study is to analyze the antibiotic sensitivity pattern of microorganisms, to study the antibiotic usage pattern, and to conduct a cost-effectiveness analysis (CEA) for the antibiotics prescribed in a tertiary care teaching hospital in south India. Methods: This prospective study was carried out in the General Medicine and Pulmonology departments of the hospital for a period of 6 months. The study was carried out in three phases: A prospective analysis to check the sensitivity pattern of microorganisms to various antibiotics, data extraction and determining the cost of antibiotics and finally evaluation of the sensitivity pattern of microorganisms and the antibiotic usage. A total of 796 documented records were analyzed. Findings: It was found that Escherichia coli was the major organism identified in 36.4% of the isolated specimens, followed by Klebsiella sp. (18.9%), Streptococcus pneumoniae (15.8%), Staphylococcus aureus (12.4%), and Pseudomonas (9.3%). The sensitivity pattern data of the prospective study revealed that E. coli was highly sensitive to Amikacin (99.3%), Klebsiella to Amikacin (93.8%), Pseudomonas to Meropenem (97.6%), and S. pneumoniae to Ofloxacin (93.8%). In the prescribing pattern study, it was found that the most common disease (21.2%) was found to be lower respiratory tract infection in 51 patients. Cephalosporins (73%), in particular Ceftriaxone (63.5%) was highly prescribed, followed by fluoroquinolones (53.9%). In the CEA, it was revealed that Ceftriaxone was the cost-effective antibiotic with a cost-effectiveness ratio (CER) of 78.27 compared to Levofloxacin, which had a CER of 95.13. Conclusion: Continuous surveillance of susceptibility testing is necessary for cost-effective customization of empiric antibiotic therapy. Furthermore, reliable statistics on antibiotic resistance and policies should be made available. PMID:24991607

Sriram, Shamungum; Aiswaria, Varghese; Cijo, Annie Eapen; Mohankumar, Thekkinkattil

2013-01-01

144

Trends in Antibiotic Treatment of Acute Otitis Media and Treatment Failure in Children, 2000-2011  

PubMed Central

Objectives Guidelines to treat acute otitis media (AOM) were published in 2004. Initial declines in prescribing were shown, but it's unknown if they were sustained. We examine trends in antibiotic dispensing patterns to treat AOM among a large population of children. We also document trends in antibiotic failure. Study Design Children aged 3 months to 12 years with an AOM diagnosis, enrolled in a commercial claims database between January 1, 2000-December 31, 2011 were included. Pharmacy claims within 7 days of diagnosis were searched for antibiotic prescriptions. Antibiotic failure was defined as a dispensing of a different antibiotic class within 2-18 days after the first prescription. We analyzed trends in antibiotic use and failure by class of antibiotic and year. Results We identified over 4 million children under 13 years with AOM. The proportion of antibiotic dispensing decreased from 66.0% in 2005 to 51.9% in 2007, after which the instances of dispensing rebounded to pre-guideline levels. However, levels began decreasing again in 2010 and the antibiotic use rate in 2011 was 57.6%. Cephalosporin prescriptions increased by 41.5% over eleven years. Antibiotic failure decreased slightly, and macrolides had the lowest proportion of failures, while all other classes had failure rates around 10%. Conclusions In recent years, antibiotic dispensing to treat AOM remains high. In addition, the use of broad-spectrum antibiotics is increasing despite having a high rate of treatment failure. Overprescribing of antibiotics and use of non-penicillin therapy for AOM treatment could lead to the development of antibiotic-resistant infections. PMID:24324680

McGrath, Leah J.; Becker-Dreps, Sylvia; Pate, Virginia; Brookhart, M. Alan

2013-01-01

145

Randomized controlled trial on the safety of intracameral cephalosporins in cataract surgery  

PubMed Central

Objective: To compare the safety profiles of intracameral cephalosporins in cataract surgery. Patients and methods: In this controlled trial, 129 patients were randomized to one of four groups to receive 1 mg of one of three cephalosporins – cefazolin, cefuroxime, or ceftazidime, or normal saline – given intracamerally during cataract surgery. Central endothelial cell density (ECD) and retinal center point thickness (CPT) were determined by specular microscopy and ocular coherence tomography, respectively, before and at 3 months after surgery. Results: There were no statistical significant differences in the changes of ECD and CPT between eyes receiving intracameral cephalosporin and control. Conclusion: The use of intracameral cefazolin, cefuroxime, or ceftazidime (1 mg in 0.1-mL solution) at the time of cataract surgery had no significant effect on ECD and CPT postoperatively. PMID:21191447

Lam, Philip TH; Young, Alvin L; Cheng, Lulu L; Tam, Patrick MK; Lee, Vincent YW

2010-01-01

146

The use of cephalosporins for gonorrhea: an update on the rising problem of resistance  

PubMed Central

Introduction Over the last several years, Neisseria gonorrhoeae has developed decreased susceptibility to extended-spectrum cephalosporins worldwide. Areas covered Gonococcal antimicrobial surveillance programs in multiple regions have documented the rise in N. gonorrhoeae isolates’ minimum inhibitory concentrations to cephalosporins, and the first cases of ceftriaxone treatment failures have been reported. These developments have prompted the use of the term “superbug,” and concerns about the emergence of untreatable gonococcal infections. In response to this threat, a variety of treatment strategies have been proposed, including increasing the dose or providing multiple doses of cephalosporins, multidrug therapy, rotating therapeutic regimens, and individualized treatment based on susceptibility testing. Expert opinion A robust public health response is needed, and includes better diagnosis and treatment of pharyngeal gonorrhea, improved surveillance of antimicrobial resistance, informed treatment approaches, and reduction of the global burden of gonococcal infections. PMID:22646654

Stoltey, Juliet E; Barry, Pennan M

2014-01-01

147

Antibiotic resistance in microbes  

Microsoft Academic Search

The treatment of infectious disease is compromised by the development of antibiotic-resistant strains of microbial pathogens. A variety of biochemical processes are involved that may keep antibiotics out of the cell, alter the target of the drug, or disable the antibiotic. Studies have shown that resistance determinants arise by either of two genetic mechanisms: mutation and acquisition. Antibiotic resistance genes

D. Mazel; J. Davies

1999-01-01

148

Antibiotics and the ribosome  

Microsoft Academic Search

Summary The ribosome is one of the main antibiotic targets in the cell. Recent years brought important insights into the mode of interaction of antibiotics with the ribo- some and mechanisms of antibiotic action. Ribosome crystallography provided a detailed view of the inter- actions between antibiotics and rRNA. Advances in biochemical techniques let us better understand how the binding of

Tanel Tenson; Alexander Mankin

2006-01-01

149

Impact of Antibiotic Use during Hospitalization on the Development of Gastrointestinal Colonization with Escherichia coli with Reduced Fluoroquinolone Susceptibility  

PubMed Central

OBJECTIVE Infections due to fluoroquinolone-resistant Escherichia coli (FQREC) are associated with significant morbidity and mortality. Fluoroquinolone resistance likely arises at the level of gastrointestinal colonization. The objective of this study was to identify risk factors for the development of FQREC gastrointestinal tract colonization in hospitalized patients, including the impact of antibiotics prescribed during hospitalization. DESIGN A prospective cohort study was conducted from 2002 to 2004 within a university health system. METHODS Hospitalized patients initially colonized with fluoroquinolone-susceptible E. coli were followed up with serial fecal sampling for new FQREC colonization or until hospital discharge or death. A Cox proportional hazards regression model was developed to identify risk factors for new FQREC colonization, with antibiotic exposure modeled as time-varying covariates. RESULTS Of 395 subjects, 73 (18.5%) became newly colonized with FQREC. Length of stay before sampling (hazard ratio [HR], 1.02 [95% confidence interval (CI), 1.1–1.03]; P = .003) and malignancy (HR, 0.37 [95% CI, 0.21–0.67]; P = .001) were significantly associated with the development of FQREC colonization. In addition, receipt of a first-generation cephalosporin (HR, 1.19 [95% CI, 1.10–1.29]; P < .001) or cefepime (HR, 1.05 [95% CI, 1.00–1.10]; P = .048) during hospitalization increased the risk of new FQREC colonization. CONCLUSIONS The acquisition of FQREC in the hospital setting is complex, and antimicrobial stewardship programs should take into account patterns of antibiotic use in implementing strategies to reduce the development of new FQREC colonization. Future studies are needed to identify risk factors for infection in hospitalized patients newly colonized with FQREC. PMID:24018924

Han, Jennifer H.; Bilker, Warren B.; Nachamkin, Irving; Tolomeo, Pam; Mao, Xiangqun; Fishman, Neil O.; Lautenbach, Ebbing

2014-01-01

150

Etiology and antibiotic resistance patterns of community-acquired urinary tract infections in J N M C Hospital Aligarh, India  

PubMed Central

Background Urinary tract infections (UTIs) remain the common infections diagnosed in outpatients as well as hospitalized patients. Current knowledge on antimicrobial susceptibility pattern is essential for appropriate therapy. Extended-Spectrum beta-Lactamase (ESBL) producing bacteria may not be detected by routine disk diffusion susceptibility test, leading to inappropriate use of antibiotics and treatment failure. The aim of this study was to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from patients with community acquired urinary tract infections (UTIs) at Aligarh hospital in India as well as identification of ESBL producers in the population of different uropathogens. Methods Urinary isolates from symptomatic UTI cases attending to the JN Medical College and hospital at Aligarh were identified by conventional methods. Antimicrobial susceptibility testing was performed by Kirby Bauer's disc diffusion method. Isolates resistant to third generation cephalosporin were tested for ESBL production by double disk synergy test method. Results Of the 920 tested sample 100 samples showed growth of pathogens among which the most prevalent were E. coli (61%) followed by Klebsiella spp (22%). The majority (66.66%) of the isolates were from female while the remaining were from male. Among the gram-negative enteric bacilli high prevalence of resistance was observed against ampicillin and co-trimoxazole. Most of the isolates were resistant to 4 or more number of antibiotics. Forty two percent of isolates were detected to produce ESBL among which 34.42 % were E. coli isolates. Conclusion This study revealed that E. coli was the predominant bacterial pathogen of community acquired UTIs in Aligarh, India. It also demonstrated an increasing resistance to Co-trimoxazole and production of extended spectrum ?-lactamase among UTI pathogens in the community. This study is useful for clinician in order to improve the empiric treatment. PMID:17378940

Akram, Mohammed; Shahid, Mohammed; Khan, Asad U

2007-01-01

151

Mutation Frequencies and Antibiotic Resistance  

Microsoft Academic Search

MULTIPLE DIMENSIONS OF THE MUTATION RATE Antibiotic resistance can be achieved by horizontal acquisi- tion of resistance genes (carried by plasmids or transposons), by recombination of foreign DNA into the chromosome, or by mutations in different chromosomal loci (15). In studies of molecular evolutionary biology, the term mutation rate is ap- plied to estimations of the rate (per generation) of

J. L. Martinez; F. Baquero

2000-01-01

152

Cefquinome (HR 111V). In vitro evaluation of a broad-spectrum cephalosporin indicated for infections in animals.  

PubMed

Cefquinome (formerly HR 111V), an aminothiazolyl cephalosporin, was compared with cefepime, cefpirome, cefotaxime, and ceftazidime against 681 clinical cultures and a challenge set of bacteria with well-characterized resistance mechanisms. Cefquinome minimum inhibitory concentrations (MIC90) for the enterobacteriaceae ranged from < or = 0.12-2 micrograms/ml with the highest MIC (4 micrograms/ml) obtained among Citrobacter freundii, Enterobacter cloacae, and Providencia stuartii strains. A total of 90% of the Pseudomonas aeruginosa were inhibited by cefquinome at < or = 8 micrograms/ml. Cefquinome activity of particular note for Gram-positive isolates included Corynebacterium jeikeium (MIC90, 8 micrograms/ml) and enterococci (MIC50, 4-8 micrograms/ml). Oxacillin-resistant Staphylococcus aureus was 32-fold less susceptible (MIC90, 16 micrograms/ml) to cefquinome than oxacillin-susceptible (MIC90, 0.5 micrograms/ml) strains. Cefquinome was very potent against fastidious isolates such as Moraxella catarrhalis (MIC90, 0.25-2 micrograms/ml); Haemophilus influenzae (MIC90, 0.06-1 micrograms/ml), Neisseria gonorrhoeae (MIC90, 0.06-0.5 micrograms/ml), and Streptococcus species (MIC90, < or = 0.03-006 micrograms/ml). When tested against organisms possessing Bush group 2 enzymes (including extended spectrum beta-lactamases), cefquinome remained active (MIC, < or = 8 micrograms/ml) against the majority of strains. This compound should be very active against pathogens generally found in animal infections and possesses a potency and spectrum comparable to the "fourth-generation" cephalosporins (cefepime and cefpirome) being investigated for human infectious diseases. PMID:7867299

Murphy, S P; Erwin, M E; Jones, R N

1994-09-01

153

Study of different off-line sample processing procedures and the measurement of antibiotic and antiviral levels in human serum by high-performance liquid chromatography.  

PubMed

We attempted to devise a preparation method for clinical samples that could be used for all antibiotics and antivirals. We studied thirteen antibiotics, including five penicillins, four cephalosporins, metronidazole, ofloxacin, and sulfamethoxazole and four protease inhibitors including indinavir, retonavir, nelfinavir, and sequinavir. We compared four sample preparation techniques including solvent precipitation, filtration and resin column. We employ HPLC methods based on a minimal number of columns and mobile phases. We were unable to find one sample preparation method that could be used for all antibiotics and antivirals. But, we did develop an algorithm for determining optimal processing procedures for all drugs. PMID:12031842

Metz, Paul; Kohlhepp, Sue J; Gilbert, D N

2002-06-25

154

Antibiotic resistance in Latin America: A cause for alarm  

Microsoft Academic Search

The burden of pneumococcal disease in Latin America is most pronounced in children aged <6 years. The increasing rate of resistance of Streptococcus pneumoniae to penicillin and other antibiotics has generated concern among health authorities, since infection by antibiotic-resistant serotypes may be associated with increased mortality. Increased resistance is due to a number of factors including high antibiotic usage in

M. Teresa Valenzuela; Ciro de Quadros

2009-01-01

155

Conjunctivitis Caused by Neisseria gonorrhoeae Isolates with Reduced Cephalosporin Susceptibility and Multidrug Resistance  

PubMed Central

We report two cases of conjunctivitis caused by Neisseria gonorrhoeae with reduced cephalosporin susceptibility. Patients showed no response to cefmenoxime eye drops and intravenous ceftriaxone administration. The patients' condition improved after the addition of oral minocycline. The isolates contained the mosaic penA for reduction of ?-lactam susceptibility. PMID:24025911

Kitagawa, Yutaka; Maruyama, Yosuke; Yamaguchi, Satoshi; Sakane, Yuri; Miyamoto, Hitoshi; Ohashi, Yuichi

2013-01-01

156

Engineering the stereochemistry of cephalosporin for specific detection of pathogenic carbapenemase-expressing bacteria.  

PubMed

Reported herein is the design of fluorogenic probes specific for carbapenem-resistant Enterobacteriaceae (CRE) and they were designed based on stereochemically modified cephalosporin having a 6,7-trans configuration. Through experiments using recombinant ?-lactamase enzymes and live bacterial species, these probes demonstrate the potential for use in the specific detection of carbapenemases, including metallo-?-lactamases in active bacterial pathogens. PMID:24764125

Shi, Haibin; Cheng, Yunfeng; Lee, Kyung Hyun; Luo, Robert F; Banaei, Niaz; Rao, Jianghong

2014-07-28

157

In Vitro and In Vivo Activities of LB 10827, a New Oral Cephalosporin, against Respiratory Pathogens  

Microsoft Academic Search

The in vitro antibacterial activities of LB 10827, a new oral cephalosporin, against common respiratory tract pathogens were compared with those of six b-lactams (cefdinir, cefuroxime, cefprozil, penicillin G, amoxicillin- clavulanate, and ampicillin), two quinolones (trovafloxacin and ciprofloxacin), and one macrolide (clarithro- mycin). The MIC of LB 10827 at which 90% of the penicillin-resistant strains of Streptococcus pneumoniae tested were

KYONG-SOOK PAEK; MU-YONG KIM; CHANG-SEOK LEE; HASIK YOUN

2000-01-01

158

[Complications from antibiotic therapy].  

PubMed

Analysis of 302 side effects of antibiotic theraphy is presented. The side effects were studied comparatively as dependent on the antibiotic group. Dependence of the toxic and toxicoallergic reactions to the antibiotics on the antibiotic blood levels were noted. Previous sensitization resulted in more frequent and earlier side effects. The analysis and clinical observations showed that antibiotic therapy should take into account the results of the laboratory tests, i.e. examination of the kidney functional state, antibiotic levels in the blood and urine, tolerance of the drug by the patient. PMID:1211892

Iurenev, P N; Sergeiuk, E M; Samo?lova, L N; Kakurina, A V

1975-10-01

159

Antibiotic Consumption and Healthcare-Associated Infections Caused by Multidrug-Resistant Gram-Negative Bacilli at a Large Medical Center in Taiwan from 2002 to 2009: Implicating the Importance of Antibiotic Stewardship  

PubMed Central

Background Better depicting the relationship between antibiotic consumption and evolutionary healthcare-associated infections (HAIs) caused by multidrug-resistant Gram-negative bacilli (MDR-GNB) may help highlight the importance of antibiotic stewardship. Methodology/Principal Findings The correlations between antibiotic consumption and MDR-GNB HAIs at a 2,700-bed primary care and tertiary referral center in Taiwan between 2002 and 2009 were assessed. MDR-GNB HAI referred to a HAI caused by MDR-Enterobacteriaceae, MDR-Pseudomonas aeruginosa or MDR-Acinetobacter spp. Consumptions of individual antibiotics and MDR-GNB HAI series were first evaluated for trend over time. When a trend was significant, the presence or absence of associations between the selected clinically meaningful antibiotic resistance and antibiotic consumption was further explored using cross-correlation analyses. Significant major findings included (i) increased consumptions of extended-spectrum cephalosporins, carbapenems, aminopenicillins/?-lactamase inhibitors, piperacillin/tazobactam, and fluoroquinolones, (ii) decreased consumptions of non-extended-spectrum cephalosporins, natural penicillins, aminopenicillins, ureidopenicillin and aminoglycosides, and (iii) decreasing trend in the incidence of the overall HAIs, stable trends in GNB HAIs and MDR-GNB HAIs throughout the study period, and increasing trend in HAIs caused by carbapenem-resistant (CR) Acinetobacter spp. since 2006. HAIs due to CR-Acinetobacter spp. was found to positively correlate with the consumptions of carbapenems, extended-spectrum cephalosporins, aminopenicillins/?-lactamase inhibitors, piperacillin/tazobactam and fluoroquinolones, and negatively correlate with the consumptions of non-extended-spectrum cephalosporins, penicillins and aminoglycosides. No significant association was found between the increased use of piperacilllin/tazobactam and increasing HAIs due to CR-Acinetobacter spp. Conclusions The trend in overall HAIs decreased and trends in GNB HAIs and MDR-GNB HAIs remained stable over time suggesting that the infection control practice was effective during the study period, and the escalating HAIs due to CR- Acinetobacter spp. were driven by consumptions of broad-spectrum antibiotics other than piperacillin/tazobactam. Our data underscore the importance of antibiotic stewardship in the improvement of the trend of HAIs caused by Acinetobacter spp. PMID:23738018

Su, Li-Hsiang; Tang, Ya-Feng; Chang, Shun-Jen; Liu, Jien-Wei

2013-01-01

160

Cephalosporin susceptibility among Neisseria gonorrhoeae isolates--United States, 2000-2010.  

PubMed

Neisseria gonorrhoeae is a major cause of pelvic inflammatory disease, ectopic pregnancy, and infertility, and it can facilitate human immunodeficiency virus (HIV) transmission. Emergence of gonococcal resistance to penicillin and tetracycline occurred during the 1970s and became widespread during the early 1980s. More recently, resistance to fluoroquinolones developed. Resistance was documented first in Asia, then emerged in the United States in Hawaii followed by other western states. It then became prevalent in all other regions of the United States. In Hawaii, fluoroquinolone resistance was first noted among heterosexuals; however, resistance in the United States initially became prevalent among men who have sex with men (MSM) before generalizing to heterosexuals. This emergence of resistance led CDC, in 2007, to discontinue recommending any fluoroquinolone regimens for the treatment of gonorrhea. CDC now recommends dual therapy for gonorrhea with a cephalosporin (ceftriaxone 250 mg) plus either azithromycin or doxycycline. This report summarizes trends in cephalosporin susceptibility among N. gonorrhoeae isolates in the United States during 2000-2010 using data from the Gonococcal Isolate Surveillance Project (GISP). During that period, the percentage of isolates with elevated minimum inhibitory concentrations (MICs) to cephalosporins (?0.25 µg/mL for cefixime and ?0.125 µg/mL for ceftriaxone) increased from 0.2% in 2000 to 1.4% in 2010 for cefixime and from 0.1% in 2000 to 0.3% in 2010 for ceftriaxone. Although cephalosporins remain an effective treatment for gonococcal infections, health-care providers should be vigilant for treatment failure and are requested to report its occurrence to state and local health departments. State and local public health departments should promote maintenance of laboratory capability to culture N. gonorrhoeae to allow testing of isolates for cephalosporin resistance. They also should develop enhanced surveillance and response protocols for gonorrhea treatment failures and report gonococcal treatment failures to CDC. PMID:21734634

2011-07-01

161

An economic model for the prevention of MRSA infections after surgery: non-glycopeptide or glycopeptide antibiotic prophylaxis?  

Microsoft Academic Search

Aim  Surgical site infection is commonly caused by Staphylococcus aureus. The multiresistant strains (MRSA) are resistant to most antibiotic prophylaxis regimens. Our aim was to explore whether\\u000a there is a threshold of MRSA prevalence at which switching to routine glycopeptide-based antibiotic prophylaxis becomes cost-effective.\\u000a \\u000a \\u000a \\u000a Methods  An indicative model was designed to explore the cost-effectiveness of vancomycin, cephalosporin or a combination, in patients

Rachel A. Elliott; Helen L. A. Weatherly; Neil S. Hawkins; Gillian Cranny; Duncan Chambers; Lindsey Myers; Alison Eastwood; Mark J. Sculpher

2010-01-01

162

Paediatric upper respiratory infections: the role of antibiotics.  

PubMed

To review current clinical evidence for the use of antibiotics in paediatric upper paediatric respiratory infections, repeated PubMed searches using the template algorithm -rhinosinusitis/otitis/ tonsillitis AND ()- with the settings: -Humans; English; All Child 0-18; Clinical trial; Review; Methanalysis; Guideline; Last 10 years- for the following comparators: antibiotic; amoxicillin; clavulanate; penicillin; cephalosporin; macrolide; erythromycin; rokitamycin; clindamycin; trimethoprim-sulfamethoxazole, cefopodoxime, cefdinir, cefuroxime, ceftriaxone. The authors clinical experience in the paediatric allergy unit of a University hospital was also drawn upon. A narrative review was drafted to update paediatricians on the topic. Many paediatric studies and guidelines were retrieved satisfying current evidence-based medicine standards. There are stringent indications for antibiotic use in URTIs. The paediatric use is widespread raising doubts on their appropriate prescription in many countries. Evidence for the efficacy of antibiotic treatment for paediatric URTIs is available and this treatment should be included in individualised patient protocols on the basis of the clinical literature. Caution must be posed at the local level taking in account epidemiologic and microbiologic data to avoid overprescription. PMID:20152083

Fiocchi, A; Calcinai, E; Beghi, G; Terracciano, L

2010-01-01

163

Cutting antibiotic use.  

PubMed

November 18 is European Antibiotic Awareness Day, an annual event that gives us the opportunity to reflect on the issues surrounding the use of antibiotics, and to find out how we can maximise the nursing contribution. PMID:25388716

Gallagher, Rose

2014-11-12

164

Reversibility of antibiotic resistance  

PubMed Central

Although theoretically attractive, the reversibility of resistance has proven difficult in practice, even though antibiotic resistance mechanisms induce a fitness cost to the bacterium. Associated resistance to other antibiotics and compensatory mutations seem to ameliorate the effect of antibiotic interventions in the community. In this paper the current understanding of the concepts of reversibility of antibiotic resistance and the interventions performed in hospitals and in the community are reviewed. PMID:24836051

2014-01-01

165

Ion-paired extraction of cephalosporins in acetone prior to their analysis by capillary liquid chromatography in environmental water and meat samples.  

PubMed

Ion-pair extraction of cephalosporins from aqueous solution into acetone by the addition of ammonium sulfate to a 1:2 (v/v) acetone-water solvent was carried out followed by their determination using reversed-phase capillary liquid chromatography. The analytes included are cephoperazone, cefquinome, cephalexin, cephapirin, cephaloniun, cephamandole, cephazolin and cephadroxile. In order to form the ion-pair, hexadecyltrimethylammonium bromide (CTAB) was selected as cationic ion-pairing agent at a concentration of 0.9 mM using 10mM phosphate buffer at pH 8 as the optimum condition for the aqueous solution. The applied methodology, named salting-out assisted liquid/liquid extraction (SALLE) involves the use of 1.25 g of ammonium sulfate as salting-out agent. The separation of cephalosporins using a Luna C18 (150 mm × 0.3mm, 5 µm, 100 Å) column was achieved under the following conditions: a gradient program combining solvent A (0.1% formic acid in water, pH 4) and solvent B (acetonitrile-methanol (50:50, v/v)), at a flow rate of 20 µl min(-1), column temperature 35°C and injection volume 7 µl with UV detection at 250 nm. The limits of quantification for the studied compounds were between 4.3 and 22.7 ?g/L for water samples and 4.1 and 73.3 ?g/kg in the case of beef samples, lower than the maximum residue limits permitted by the EU for this kind of food. The developed methodology has demonstrated its suitability for the analysis of these widely applied antibiotics in environmental water and meat samples, including beef and pork muscle, with high sensitivity, precision and satisfactory recoveries. PMID:24054686

Quesada-Molina, Carolina; García-Campaña, Ana M; del Olmo-Iruela, Monsalud

2013-10-15

166

Experimental evolution of antibiotic resistance  

E-print Network

SUPERBUGS! Experimental evolution of antibiotic resistance #12;REVIEW Most bacteria be pathogens. Cancer is an infectious disease. #12;REVIEW Flu is treated with antibiotics. Antibiotics only treat bacterial infections. Susceptible organisms survive antibiotic

Rose, Michael R.

167

Nosocomial infections due to serratia marcescens — Clinical findings, antibiotic susceptibility patterns and fine typing  

Microsoft Academic Search

Summary We report on nosocomial infections caused bySerratia marcescens occurring in a neonatal intensive care unit and a children's ward for cardiac intensive care. According to the plasmid pattern analysis, all isolated epidemic strains belonged to one clone. Multidrug resistance, even to cephalosporins of the third generation and amikacin, was characteristic for all strains. Certain markers ofS. marcescens (haemolysin, proteases,

Renate Bollmann; Elke Halle; Wanda Sokolowska-Köhler; Petra Buchholz; E. L. Grauel; I. Klare; H. Tschäpe; W. Witte

1989-01-01

168

Application of high-performance liquid chromatography of some antibiotics in clinical microbiology.  

PubMed

During recent years high-performance liquid chromatography has become an excellent tool for the determination of antibiotics in biological fluids. Compared with biological assays, the major benefits of this method are specificity and rapidity. In particular, the determination of biologically inactive metabolites emphasizes that this technique plays an outstanding role for the analysis of antibiotics. This paper describes how the method can be used in the analysis of several antibiotics and demonstrates the efficacy of this method for clinical microbiology. Methods for the determination in biological fluids of acylaminopenicillins (azlocillin, mezlocillin, piperacillin and aspoxicillin), quinolones (ciprofloxacine, norfloxacine and ofloxacine), a penem (imipenem) and a cephalosporin (cefixime) are summarized. Furthermore, their application to in vitro studies and their trial in clinical studies are described. PMID:3165979

Knöller, J; König, W; Schönfeld, W; Bremm, K D; Köller, M

1988-06-01

169

Reverse phase high speed liquid chromatography of antibiotics. III. Use of ultra high performance columns and ion-pairing techniques.  

PubMed

Improved methods for the separation and quantitation of cephalosporin, penicillin, aminoglycoside and anthracycline antibiotics are presented. The use of ultra high performance 5 micrometer phase columns combined with the added dimension of ion-pairing greatly increases the ease of separation and speed of analysis of complex antibiotic mixtures. Antibiotics in a variety of dosage forms and in fermentation broths have been examined in order to provide the maximum data on impurities to meet regulatory requirements for drug safety, purity and efficacy. Mixtures of antibiotics have been analyzed to demonstrate the improved separations, increased efficiency and shortened analysis times possible with ultra thin performance columns. Under these improved conditions, the danger of multiple components in a single peak are markedly reduced. PMID:6945300

White, E R; Zarembo, J E

1981-07-01

170

Certain attributes of the sexual ecosystem of high-risk MSM have resulted in an altered microbiome with an enhanced propensity to generate and transmit antibiotic resistance.  

PubMed

Surveillance data from a number of countries have indicated that antibiotic resistance in Neisseriagonorrhoea is strongly associated with men who have sex with men (MSM). This manuscript advances the hypothesis that certain features of the MSM sexual ecosystem may be responsible for this association. It is argued that in comparison with heterosexuals, high-risk MSM (hrMSM) have a higher prevalence of oro-penile, oro-rectal and anal sex which facilitates an enhanced mixing of the pharyngeal, rectal and penile microbiomes. In addition, hrMSM have an increased number of sexual partners per unit time and an increased prevalence of sexual relationships overlapping in time. The increased flux of microbiomes between different body habitats between sexual partners, in combination with the increased connectivity of the sexual network, serve to create a novel high-risk MSM sexual ecosystem with important consequences for the genesis and spread of antibiotic resistance. PMID:24857261

Kenyon, C; Osbak, K

2014-08-01

171

Finding alternatives to antibiotics.  

PubMed

The spread of antibiotic-resistant pathogens requires new treatments. As the rate of development of new antibiotics has severely declined, alternatives to antibiotics must be considered in both animal agriculture and human medicine. Products for disease prevention are different from those for disease treatment, and examples of both are discussed here. For example, modulating the gut microbial community, either through feed additives or fecal transplantation, could be a promising way to prevent certain diseases; for disease treatment, non-antibiotic approaches include phage therapy, phage lysins, bacteriocins, and predatory bacteria. Interestingly, several of these methods augment antibiotic efficacy by improving bacterial killing and decreasing antibiotic resistance selection. Because bacteria can ultimately evolve resistance to almost any therapeutic agent, it is important to continue to use both antibiotics and their alternatives judiciously. PMID:24953233

Allen, Heather K; Trachsel, Julian; Looft, Torey; Casey, Thomas A

2014-09-01

172

Antibiotic resistance in Chlamydiae  

PubMed Central

There are few documented reports of antibiotic resistance in Chlamydia and no examples of natural and stable antibiotic resistance in strains collected from humans. While there are several reports of clinical isolates exhibiting resistance to antibiotics, these strains either lost their resistance phenotype in vitro, or lost viability altogether. Differences in procedures for chlamydial culture in the laboratory, low recovery rates of clinical isolates and the unknown significance of heterotypic resistance observed in culture may interfere with the recognition and interpretation of antibiotic resistance. Although antibiotic resistance has not emerged in chlamydiae pathogenic to humans, several lines of evidence suggest they are capable of expressing significant resistant phenotypes. The adept ability of chlamydiae to evolve to antibiotic resistance in vitro is demonstrated by contemporary examples of mutagenesis, recombination and genetic transformation. The isolation of tetracycline-resistant Chlamydia suis strains from pigs also emphasizes their adaptive ability to acquire antibiotic resistance genes when exposed to significant selective pressure. PMID:20860486

Sandoz, Kelsi M; Rockey, Daniel D

2011-01-01

173

Genetic Architecture of Intrinsic Antibiotic Susceptibility  

PubMed Central

Background Antibiotic exposure rapidly selects for more resistant bacterial strains, and both a drug's chemical structure and a bacterium's cellular network affect the types of mutations acquired. Methodology/Principal Findings To better characterize the genetic determinants of antibiotic susceptibility, we exposed a transposon-mutagenized library of Escherichia coli to each of 17 antibiotics that encompass a wide range of drug classes and mechanisms of action. Propagating the library for multiple generations with drug concentrations that moderately inhibited the growth of the isogenic parental strain caused the abundance of strains with even minor fitness advantages or disadvantages to change measurably and reproducibly. Using a microarray-based genetic footprinting strategy, we then determined the quantitative contribution of each gene to E. coli's intrinsic antibiotic susceptibility. We found both loci whose removal increased general antibiotic tolerance as well as pathways whose down-regulation increased tolerance to specific drugs and drug classes. The beneficial mutations identified span multiple pathways, and we identified pairs of mutations that individually provide only minor decreases in antibiotic susceptibility but that combine to provide higher tolerance. Conclusions/Significance Our results illustrate that a wide-range of mutations can modulate the activity of many cellular resistance processes and demonstrate that E. coli has a large mutational target size for increasing antibiotic tolerance. Furthermore, the work suggests that clinical levels of antibiotic resistance might develop through the sequential accumulation of chromosomal mutations of small individual effect. PMID:19462005

Tavazoie, Saeed

2009-01-01

174

Microb Ecol . Author manuscript Human intestinal microbiota gene risk factors for antibiotic-associated  

E-print Network

for antibiotic-associated diarrhea: perspectives for prevention. Risk factors for antibiotic-associated diarrhea France De La Cocheti reè Abstract Antibiotic-associated diarrhea (AAD important for clinicians. For this reason, we conducted a hypothesis-generating study focused on antibiotic

Paris-Sud XI, Université de

175

A novel sensor for cephalosporins based on electrocatalytic oxidation by poly(o-anisidine)/SDS/Ni modified carbon paste electrode.  

PubMed

In this work for first time, the electrocatalytic oxidations of some cephalosporins were carried out by poly(o-anisidine)/SDS/Ni modified carbon paste electrode using cyclic voltammetry, chronoamperometry and chronocoulometry methods. At first, poly(o-anisidine) was formed by cyclic voltammetry in monomer solution containing sodium dodesyl sulfate (SDS), on carbon paste electrode surface. Then, Ni(II) ions were incorporated to electrode by immersion of the polymeric modified electrode having amine group in 0.1molL(-1) Ni(II) ion solution. A good redox behavior was observed for the Ni(OH)(2)/NiOOH couple on the surface of this electrode. Cephalosporins were successfully oxidized on the surface of this nickel ions dispersed poly(o-anisidine) modified carbon paste electrode. The electrocatalytic oxidation peak currents of cephalosporins were linearly dependent on their concentration. Electrode was successfully applied to determine cephalosporins in pharmaceutical preparations. PMID:20441933

Ojani, Reza; Raoof, Jahan-Bakhsh; Zamani, Saeed

2010-06-15

176

Ventilator-associated pneumonia in an adult clinical-surgical intensive care unit of a Brazilian university hospital: incidence, risk factors, etiology, and antibiotic resistance.  

PubMed

The objective of this study was to evaluate clinical characteristics, etiology, and resistance to antimicrobial agents, among patients with ventilator-associated pneumonia (VAP). A case study vs. patients control under mechanical ventilation and hospitalized into clinical-surgical adults ICU of HC-UFU was performed from March/2005 to March/2006. Patients under ventilation for over 48 h were included in the study including 84 with diagnosis of VAP, and 191 without VAP (control group). Laboratory diagnosis was carried out through quantitative microbiological evaluation of tracheal aspirate. The identification of pathogens was performed by classical microbiological tests, and the antibiotics sensitivity spectrum was determined through the CLSI technique. VAP incidence rate over 1,000 days of ventilation was 24.59. The mean (+/- SD) duration of mechanical ventilation prior to VAP diagnosis was 23.2 +/- 17.2 days. By multivariate analysis the risk factors predisposing for VAP were: mechanical ventilation time and mechanical ventilation > seven days, tracheostomy and use of > or = three antibiotics. Mortality rate was high (32.1 %) but lower than that of the control group (46.5%). Major pathogens were identified in most of patients (95.2%) and included: Pseudomonas aeruginosa (29%), Staphylococcus aureus (26%), Enterobacter/Klebsiella/Serratia (19%) and Acinetobacter spp. (18%), with expressive frequencies of P. aeruginosa (52%), S. aureus (65.4%) and Enterobacteriaceae (43.7%) resistant to imipenem, oxacillin and 3/4 generation cephalosporins, respectively. In conclusion, our observation showed VAPs caused by multiresistant microorganisms, the prescription of > or = three antibiotics, and mortality with unacceptably high rates. The practice of de-escalation therapy appears to be urgently needed in order to improve the situation. PMID:18553020

Rocha, Laura de Andrade da; Vilela, Carolina Assis Pereira; Cezário, Renata Cristina; Almeida, Alair Benedito; Gontijo Filho, Paulo

2008-02-01

177

In Vitro Evaluation of the Antimicrobial Activity of Ceftaroline against Cephalosporin-Resistant Isolates of Streptococcus pneumoniae  

Microsoft Academic Search

Increasing pneumococcal resistance to extended-spectrum cephalosporins warrants the search for novel agents with activity against such resistant strains. Ceftaroline, a parenteral cephalosporin currently in phase 3 clinical development, has demonstrated potent in vitro activity against resistant gram-positive organisms, including penicillin-resistant Streptococcus pneumoniae. In this study, the activity of ceftaroline was evaluated against highly cefotaxime-resistant isolates of pneumococci from the Active

Lesley McGee; Donald Biek; Yigong Ge; Magderie Klugman; M. du Plessis; A. M. Smith; B. Beall; C. G. Whitney; K. P. Klugman

2009-01-01

178

Bacterial Profile, Antibiotic Sensitivity and Resistance of Lower Respiratory Tract Infections in Upper Egypt  

PubMed Central

Background Lower respiratory tract infections (LRTI) account for a considerable proportion of morbidity and antibiotic use. We aimed to identify the causative bacteria, antibiotic sensitivity and resistance of hospitalized adult patients due to LRTI in Upper Egypt. Methods A multicentre prospective study was performed at 3 University Hospitals for 3 years. Samples included sputum or bronchoalveolar lavage (BAL) for staining and culture, and serum for serology. Samples were cultured on 3 bacteriological media (Nutrient, Chocolate, MacConkey's agars). Colonies were identified via MicroScan WalkAway-96. Pneumoslide IgM kit was used for detection of atypical pathogens via indirect immunofluorescent assay. Results The predominant isolates in 360 patients with CAP were S. pneumoniae (36%), C. pneumoniae (18%), and M. pneumoniae (12%). A higher sensitivity was recorded for moxifloxacin, levofloxacin, macrolides, and cefepime. A higher of resistance was recorded for doxycycline, cephalosporins, and ?-lactam-?-lactamase inhibitors. The predominant isolates in 318 patients with HAP were, methicillin-resistant Staphylococcus aureus; MRSA (23%), K. pneumoniae (14%), and polymicrobial in 12%. A higher sensitivity was recorded for vancomycin, ciprofloxacin, and moxifloxacin. Very high resistance was recorded for ?-lactam-?-lactamase inhibitors and cephalosporins. The predominant organisms in 376 patients with acute exacerbation of chronic obstructive pulmonary diseases (AECOPD) were H. influnzae (30%), S. pneumoniae (25%), and M. catarrhalis (18%). A higher sensitivity was recorded for moxifloxacin, macrolides and cefepime. A higher rate of resistance was recorded for aminoglycosides and cephalosporins. Conclusions The most predominant bacteria for CAP in Upper Egypt are S. pneumoniae and atypical organisms, while that for HAP are MRSA and Gram negative bacteria. For acute exacerbation of COPD, H. influnzae was the commonest organism. Respiratory quinolones, macrolides, and cefepime are the most efficient antibiotics in treatment of LRTI in our locality. PMID:24106606

Agmy, Gamal; Mohamed, Sherif; Gad, Yaser; Farghally, Esam; Mohammedin, Hamdy; Rashed, Hebba

2013-01-01

179

Prodrugs of cephalosporin RWJ-333441 (MC-04,546) with improved aqueous solubility.  

PubMed

To improve the aqueous solubility of anti-methicillin-resistant Staphylococcus aureus cephalosporin RWJ-333441 for parenteral administration, acyl derivatives of the C-3 primary amino group were prepared and evaluated for solubility, cleavage in serum in vitro, and conversion to RWJ-333441 in vivo. Improved solubility at physiologic pH values and release of RWJ-333441 in vitro and in vivo were observed for several prodrugs, including the aspartate derivative RWJ-333442. PMID:12760896

Hecker, Scott J; Calkins, Trevor; Price, Mary E; Huie, Keith; Chen, Sharon; Glinka, Tomasz W; Dudley, Michael N

2003-06-01

180

Plasmid-Mediated Resistance to Expanded-Spectrum Cephalosporins among Enterobacter aerogenes Strains  

Microsoft Academic Search

Resistance to expanded-spectrum cephalosporins commonly develops in Enterobacter aerogenes during ther- apy due to selection of mutants producing high levels of the chromosomal Bush group 1 b-lactamase. Recently, resistant strains producing plasmid-mediated extended-spectrum b-lactamases (ESBLs) have been isolated as well. A study was designed to investigate ESBL production among 31 clinical isolates of E. aerogenes from Richmond, Va., with decreased

JOHANN D. D. PITOUT; KENNETH S. THOMSON; NANCY D. HANSON; ANTON F. EHRHARDT; PHILIP COUDRON; CHRISTINE C. SANDERS

1998-01-01

181

Directed evolution and rational approaches to improving Streptomyces clavuligerus deacetoxycephalosporin C synthase for cephalosporin production  

Microsoft Academic Search

It is approximately 60 years since the discovery of cephalosporin C in Cephalosporium acremonium. Streptomycetes have since been found to produce the structurally related cephamycin C. Studies on the biosynthetic pathways\\u000a of these two compounds revealed a common pathway including a step governed by deacetoxycephalosporin C synthase which catalyses\\u000a the ring-expansion of penicillin N to deacetoxycephalosporin C. Because of the therapeutic

Kian-Sim Goo; Chun-Song Chua; Tiow-Suan Sim

2009-01-01

182

Antibiotics in the environment  

PubMed Central

Molecules with antibiotic properties, produced by various microbes, have been around long before mankind recognized their usefulness in preventing and treating bacterial infections. Bacteria have therefore been exposed to selection pressures from antibiotics for very long times, however, generally only on a micro-scale within the immediate vicinity of the antibiotic-producing organisms. In the twentieth century we began mass-producing antibiotics, mainly synthetic derivatives of naturally produced antibiotic molecules, but also a few entirely synthetic compounds. As a consequence, entire bacterial communities became exposed to unprecedented antibiotic selection pressures, which in turn led to the rapid resistance development we are facing today among many pathogens. We are, rightly, concerned about the direct selection pressures of antibiotics on the microbial communities that reside in or on our bodies. However, other environments, outside of our bodies, may also be exposed to antibiotics through different routes, most often unintentionally. There are concerns that increased selection pressures from antibiotics in the environment can contribute to the recruitment of resistance factors from the environmental resistome to human pathogens. This paper attempts to 1) provide a brief overview of environmental exposure routes of antibiotics, 2) provide some thoughts about our current knowledge of the associated risks for humans as well as ecosystems, and 3) indicate management options to reduce risks. PMID:24646081

2014-01-01

183

Availability of Antibiotics for Purchase Without a Prescription on the Internet  

PubMed Central

PURPOSE Reducing inappropriate use of antibiotics is key to many antibiotic resistance initiatives. Most initiatives, however, focus almost exclusively on controlling prescribing by health care clinicians and do not focus on patient self-medication. The purpose of this study was to examine antibiotics available to patients without a prescription, a phenomenon on the Internet. METHODS We conducted an Internet search using 2 major search engines (Google and Yahoo) with the key words “purchase antibiotics without a prescription” and “online (English only).” Vendors were compared according to the classes of antibiotics available, quantity, shipping locations, and shipping time. RESULTS We found 138 unique vendors selling antibiotics without a prescription. Of those vendors, 36.2% sold antibiotics without a prescription, and 63.8% provided an online prescription. Penicillins were available on 94.2% of the sites, macrolides on 96.4%, fluoroquinolones on 61.6%, and cephalosporins on 56.5%. Nearly all, 98.6%, ship to the United States. The mean delivery time was 8 days, with 46.1% expecting delivery in more than 7 days. Among those selling macrolides (n = 133), 93.3% would sell azithromycin in quantities consistent with more than a single course of medication. Compared with vendors that require a medical interview, vendors who sell antibiotics without a prescription were more likely to sell quantities in excess of a single course, and the antibiotics were more likely to take more than 7 days to reach the customer. CONCLUSIONS Antibiotics are freely available for purchase on the Internet without a prescription, a phenomenon that encourages self-medication and low quality of care. PMID:19752471

Mainous, Arch G.; Everett, Charles J.; Post, Robert E.; Diaz, Vanessa A.; Hueston, William J.

2009-01-01

184

Platforms for antibiotic discovery.  

PubMed

The spread of resistant bacteria, leading to untreatable infections, is a major public health threat but the pace of antibiotic discovery to combat these pathogens has slowed down. Most antibiotics were originally isolated by screening soil-derived actinomycetes during the golden era of antibiotic discovery in the 1940s to 1960s. However, diminishing returns from this discovery platform led to its collapse, and efforts to create a new platform based on target-focused screening of large libraries of synthetic compounds failed, in part owing to the lack of penetration of such compounds through the bacterial envelope. This article considers strategies to re-establish viable platforms for antibiotic discovery. These include investigating untapped natural product sources such as uncultured bacteria, establishing rules of compound penetration to enable the development of synthetic antibiotics, developing species-specific antibiotics and identifying prodrugs that have the potential to eradicate dormant persisters, which are often responsible for hard-to-treat infections. PMID:23629505

Lewis, Kim

2013-05-01

185

Natural antibiotic susceptibility of Escherichia coli, Shigella, E. vulneris, and E. hermannii strains.  

PubMed

The natural antibiotic susceptibility of 139 Escherichia coli strains (including 18 enterohemorrhagic E. coli), 73 Shigella strains (S. sonnei (n = 37), S. flexneri (n = 29), S. boydii (n = 6), S. dysenteriae (n = 1)), 23 E. vulneris, and 20 E. hermannii strains toward 71 antibiotics was examined. MICs were determined using a microdilution procedure. All examined taxa were naturally sensitive/intermediate toward tetracyclines, aminoglycosides, some penicillins (amoxycillin/clavulanate, ampicillin/sulbactam, piperacillin [with and without tazobactam], mezlocillin, azlocillin), cephalosporins, carbapenems, monobactams, quinolones, trimethoprim, cotrimoxazole, and chloramphenicol and were naturally resistant/intermediate toward benzylpenicillin, oxacillin, macrolides, lincosamides, glycopeptides, rifampicin, and fusidic acid. No differences in natural antibiotic susceptibility were seen between enterohemorrhagic and other E. coli strains. Likewise, with one exception, no significant differences in natural antibiotic susceptibility were seen either among the Shigella subgroups or between Shigella and E. coli. The natural population of S. flexneri was slightly more susceptible to chloramphenicol than the natural populations of other taxa within the Shigella-E. coli complex. E. vulneris and E. hermannii showed susceptibility patterns to many antibiotics similar to Shigella and E. coli, but there were other antibiotics toward which there were significant differences in natural susceptibility. E. vulneris and E. hermannii were less susceptible to nitrofurantoin and slightly more susceptible to several aminoglycosides than E. coli and Shigella. E. hermannii was the only species that was naturally resistant/intermediate to ticarcillin and amoxycillin (DIN standard). The addition of clavulanic acid to the latter resulted in a decrease of seven twofold dilution steps (E. vulneris: four twofold dilution steps, E. coli/Shigella: two twofold dilution steps) of the MICs of the natural population. With the exception of cefoperazone and cefepime, E. hermannii was more susceptible to cephalosporins than strains of the other species. E. vulneris was the species most susceptible to ticarcillin and the only species that was highly resistant to fosfomycin (MIC > 256 micrograms/mL). The antibiotic susceptibility to fosfomycin was also unique for E. hermannii (MIC 32-128 micrograms/mL), whereas the natural populations of E. coli and Shigella showed lower MIC values. The data of this study represent an assessment of the natural susceptibility of strains of Escherichia spp. and Shigella subgroups to a wide range of antibiotics. These databases can be used for the validation of antibiotic susceptibility test results of Escherichia spp. and shigellae. The conformity of the natural antibiotic susceptibility test results not only among the Shigella subgroups but also between Shigella and E. coli support the status of Shigella as a subgroup of the species E. coli. PMID:10092968

Stock, I; Wiedemann, B

1999-03-01

186

Antibiotic prescriptions in children  

Microsoft Academic Search

Results: In the year surveyed, 511270 antibiotic prescriptions in 219 257 children were identified. In all, 52.9% of children received at least one antibiotic; this percentage decreased with age, ranging from 70.4% in children 1-2 years old to 35.8% in children >11 years old. Fifty-two per cent of inhabitants under the age of 15 years were treated with systemic antibiotics

D. Resi; M. Milandri; M. L. Moro; Viale Aldo Moro

2003-01-01

187

Aetiology and antibiotic resistance issues regarding urological procedures.  

PubMed

There are specific indications in urological procedures [transurethral resection of the prostate (TURP), transurethral resection of the bladder (TURB), endoscopic procedures, and all interventions classified as contaminated or dirty] requiring antibiotic prophylaxis. Most postoperative infections are caused by enterococci of the Gram-positive strains and Enterobacteriaceae of the Gram-negative ones. As reported by the European Center for Disease Prevention and Control (ECDC), there are increasing numbers of antibiotic-resistant pathogens. Most Enterococcus faecium strains are ampicillin-resistant and the Enterobacteriaceae have a high prevalence of extended-spectrum beta-lactamase (ESBL) producers, for which the cephalosporins and penicillins are not drugs of choice. In recent years, there are also increasing numbers of Gram-negative strains that are able to produce carbapenemases and for which the only therapeutic options are gentamicin, tigecycline and colistin. An alternative to these drugs, from a prophylactic point of view, is fosfomycin, an old antibiotic that maintains bactericidal activity against both enterococci and multidrug-resistant Enterobacteriaceae. Available in an oral formulation as trometamol salt, fosfomycin reaches high plasma and urine concentrations, and is therefore a possible alternative to other drugs both for therapy and urological prophylaxis. PMID:25245707

Concia, Ercole; Azzini, Anna Maria

2014-10-01

188

Antibiotic susceptibility survey of Neisseria gonorrhoeae in Thailand.  

PubMed

The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending sexually transmitted disease clinics in Cholburi and Bangkok, Thailand, were determined by agar dilution. Some 28.2% of isolates produced beta-lactamase. A total of 97.9% of beta-lactamase-positive and 51% of beta-lactamase-negative isolates tested were resistant to penicillin (MICs, greater than or equal to 2 micrograms/ml), 70% of isolates tested were resistant to tetracycline (MICs, greater than or equal to 2 micrograms/ml), and 91% of isolates tested were susceptible to spectinomycin (MICs, less than or equal to 64 micrograms/ml). The MICs for 90% of isolates for the other drugs tested were 2 micrograms/ml for erythromycin, 2 micrograms/ml for cefoxitin, 1 micrograms/ml for cefuroxime, 0.125 micrograms/ml for cefpodoxime, 0.06 micrograms/ml for cefotaxime, 0.25 micrograms/ml for ceftazidime, 0.03 micrograms/ml for ceftizoxime, 0.03 micrograms/ml for ceftriaxone, 0.03 micrograms/ml for cefixime, 0.06 micrograms/ml for aztreonam, 0.008 micrograms/ml for ciprofloxacin, 0.125 micrograms/ml for norfloxacin, and 0.075 micrograms/ml for ofloxacin. Fewer than 1.5% of isolates were resistant to the extended-spectrum cephalosporins tested. Some 0.3% or fewer isolates were resistant to broad-spectrum cephalosporins, fluoroquinolones, or the monobactam aztreonam. Antibiotic resistance among N. gonorrhoeae isolates from Cholburi and Bangkok in May 1990 appeared to be primarily limited to penicillin and tetracycline, which are no longer used to control gonorrhea. Spectinomycin, which has been in general use against gonorrhea in Thailand since 1983, has dwindling utility, with resistance at a level of 8.9%. PMID:1416851

Clendennen, T E; Echeverria, P; Saengeur, S; Kees, E S; Boslego, J W; Wignall, F S

1992-08-01

189

Generation of broad specificity antibodies for sulfonamide antibiotics and development of an enzyme-linked immunosorbent assay (ELISA) for the analysis of milk samples.  

PubMed

Immunoreagents appropriately produced to detect a wide range of sulfonamide antibiotic congeners have been used to develop a highly sensitive enzyme-linked immunosorbent assay (ELISA). The selectivity has been achieved by combining antibodies raised against 5-[6-(4-aminobenzenesulfonylamino)pyridin-3-yl]-2-methylpentanoic acid (SA1), covalently coupled to horseshoe crab hemocyanin (HCH), and 5-[4-(amino)phenylsulfonamide]-5-oxopentanoic acid (SA2), coupled to ovalbumin (OVA), on an indirect ELISA format. The immunizing hapten has been designed to address selectivity against the common aminobenzenesulfonylamino moieties, using theoretical calculations and molecular modeling tools. Hapten SA1 has been synthesized in four steps from methyl 5-(4-amino-3-pyridinyl)-2-methyl-4-pentenoate through a Heck reaction, under Jeffery conditions, to avoid introduction of additional epitopes in the linker. The microplate immunoassay developed is able to reach the necessary detectability for the determination of the sulfonamide antibiotics most frequently used in the veterinary field, in compliance with the EC Regulation 2377/90. As an example, the IC(50) and LOD values accomplished for sulfapyridine are 2.86 +/- 0.24 and 0.13 +/- 0.03 microg L(-1), respectively. Studies performed with different types of milk samples demonstrate that direct and accurate measurements can be performed in this type of matrix without any previous sample cleanup method. PMID:19154159

Adrian, Javier; Font, Héctor; Diserens, Jean-Marc; Sánchez-Baeza, Francisco; Marco, M-Pilar

2009-01-28

190

On the use of antibiotics to reduce rhizoplane microbial populations in root physiology and ecology investigations  

NASA Technical Reports Server (NTRS)

No straightforward method exists for separating the proportion of ion exchange and respiration due to rhizoplane microbial organisms from that of root ion exchange and respiration. We examined several antibiotics that might be used for the temporary elimination of rhizoplane bacteria from hydroponically grown wheat roots (Triticum aestivum cv. Veery 10). Each antibiotic was tested for herbicidal activity and plate counts were used to enumerate bacteria and evaluate antibiotic kinetics. Only lactam antibiotics (penicillins and cephalosporins) did not reduce wheat growth rates. Aminoglycosides, the pyrimidine trimethoprim, colistin and rifampicin reduced growth rates substantially. Antibiotics acted slowly, with maximum reductions in rhizoplane bacteria occurring after more than 48 h of exposure. Combinations of nonphytotoxic antibiotics reduced platable rhizoplane bacteria by as much as 98%; however, this was generally a reduction from about 10(9) to 10(6) colony forming units per gram of dry root mass, so that many viable bacteria remained on root surfaces. We present evidence which suggests that insufficient bacterial biomass exists on root surfaces of nonstressed plants grown under well-aerated conditions to quantitatively interfere with root nitrogen absorption measurements.

Smart, D. R.; Ferro, A.; Ritchie, K.; Bugbee, B. G.

1995-01-01

191

Access to antibiotics in New Delhi, India: implications for antibiotic policy  

PubMed Central

Objective The present survey was conducted to investigate the price and availability of a basket of 24 essential antibiotics and eight high-end antibiotics at various levels of health care in public and private sector in National Capital Territory of Delhi, India using standardized WHO/HAI methodology. Methods Data on procurement price and availability was collected from three public healthcare providers in the state: the federal (central) government, state government and Municipal Corporation of Delhi (MCD). Overall a total of 83 public facilities, 68 primary care, 10 secondary cares and 5 tertiary care facilities were surveyed. Data was also collected from private retail (n?=?40) and chain pharmacies (n?=?40) of a leading corporate house. Prices were compared to an international reference price (expressed as median price ratio-MPR). Results Public sector: Delhi state government has its essential medicine list (Delhi state EML) and was using Delhi state EML 2007 for procurement; the other two agencies had their own procurement list. All the antibiotics procured including second and third generation antibiotics except for injections were available at primary care facilities. Antibiotic available were on the basis of supply rather than rationality or the Delhi state EML and none was 100% available. There was sub-optimal availability of some essential antibiotics while other non-essential ones were freely available. Availability of antibiotics at tertiary care facilities was also sub-optimal. Private sector: Availability of antibiotics was good. For most of the antibiotics the most expensive and popular trade names were often available. High-end antibiotics, meropenam, gemifloxacin, and moxifloxacin were commonly available. In retail pharmacies some newer generation non-essential antibiotics like gemifloxacin were priced lower than the highest-priced generic of amoxicillin?+?clavulanic acid, azithromycin, and cefuroxime aexitl. Conclusions Inappropriate availability and pricing of newer generation antibiotics, which may currently be bought without prescription, is likely to lead to their over-use and increased resistance. All providers should follow the EML of whichever of the three concerned Delhi public sector agencies that it is under and these EMLs should follow the essential medicine concept. The Indian regulatory authorities need to consider urgently, drug schedules and pricing policies that will curtail inappropriate access to new generation antibiotics. PMID:24764541

2013-01-01

192

Comparative study of the LC-MS/MS and UPLC-MS/MS for the multi-residue analysis of quinolones, penicillins and cephalosporins in cow milk, and validation according to the regulation 2002/657/EC.  

PubMed

The aim of this study was to develop and validate an analytical method to simultaneously determine European Union-regulated ?-lactams (penicillins and cephalosporins) and quinolones in cow milk. The procedure involves a new solid phase extraction (SPE) to clean-up and pre-concentrate the three series of antibiotics before analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). LC-MS/MS and UPLC-MS/MS techniques were also compared. The method was validated according to the Directive 2002/657/EC and subsequently applied to 56 samples of raw cow milk supplied by the Laboratori Interprofessional Lleter de Catalunya (ALLIC) (Laboratori Interprofessional Lleter de Catalunya, Control Laboratory Interprofessional of Milk of Catalunya). PMID:21820979

Junza, A; Amatya, R; Barrón, D; Barbosa, J

2011-09-01

193

Perioperative Pharmacology: Antibiotic Administration  

Microsoft Academic Search

Accurate and timely administration of antibiotics is a crucial element of perioperative patient care but, often, pharmacologic implications of antibiotics are overlooked or misunderstood. Preventable medication errors that involve antimicrobials occur throughout the perioperative continuum. Examples of errors associated with antimicrobial use include omitted doses, duplicate doses, incorrect doses, and antimicrobial products given to patients with preexisting allergies. Perioperative nurses

Linda Wanzer; Bradlee Goeckner; Rodney W. Hicks

2011-01-01

194

The future of antibiotics.  

PubMed

Antibiotic resistance continues to spread even as society is experiencing a market failure of new antibiotic research and development (R&D). Scientific, economic, and regulatory barriers all contribute to the antibiotic market failure. Scientific solutions to rekindle R&D include finding new screening strategies to identify novel antibiotic scaffolds and transforming the way we think about treating infections, such that the goal is to disarm the pathogen without killing it or modulate the host response to the organism without targeting the organism for destruction. Future economic strategies are likely to focus on 'push' incentives offered by public-private partnerships as well as increasing pricing by focusing development on areas of high unmet need. Such strategies can also help protect new antibiotics from overuse after marketing. Regulatory reform is needed to re-establish feasible and meaningful traditional antibiotic pathways, to create novel limited-use pathways that focus on highly resistant infections, and to harmonize regulatory standards across nations. We need new antibiotics with which to treat our patients. But we also need to protect those new antibiotics from misuse when they become available. If we want to break the cycle of resistance and change the current landscape, disruptive approaches that challenge long-standing dogma will be needed. PMID:25043962

Spellberg, Brad

2014-01-01

195

The surface protein Lmo1941 with LysM domain influences cell wall structure and susceptibility of Listeria monocytogenes to cephalosporins.  

PubMed

Listeria monocytogenes is a Gram-positive bacterium causing rare but dangerous cases of disease in humans and animals. The ?-lactams penicillin G and ampicillin are the antibiotics of choice in the treatment of listeriosis. Recently, lmo1941, encoding a surface protein of L. monocytogenes with unknown function, was identified as a gene transcriptionally upregulated under penicillin G pressure. In this study, the effect of lmo1941 knockout on the susceptibility of L. monocytogenes to ?-lactams was examined. Deletion mutant in lmo1941 was constructed and subjected to studies, which revealed that the deletion of lmo1941 had no effect on susceptibility and tolerance to penicillin G and ampicillin but resulted, however, in increased susceptibility of L. monocytogenes to several cephalosporins. Subsequently, the potential effect of lmo1941 mutation on the cell wall of L. monocytogenes was investigated. The analysis revealed quantitative changes in the muropeptide profile of peptidoglycan and a decrease in density of the high-density zone of cell wall of the mutant strain. Both these changes were observed in cells taken from the stationary phase. These results indicate that the surface protein Lmo1941 affects peptidoglycan composition and cell wall structure of L. monocytogenes in the stationary phase of growth. PMID:24974853

Krawczyk-Balska, Agata; Korsak, Dorota; Popowska, Magdalena

2014-08-01

196

Neisseria gonorrhoeae and extended-spectrum cephalosporins in California: surveillance and molecular detection of mosaic penA  

PubMed Central

Background The spread of Neisseria gonorrhoeae strains with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins is a major public health problem. While much work has been performed internationally, little is known about the genetics or molecular epidemiology of N. gonorrhoeae isolates with reduced susceptibility to extended-spectrum cephalosporins in the United States. The majority of N. gonorrhoeae infections are diagnosed without a live culture. Molecular tools capable of detecting markers of extended-spectrum cephalosporin resistance are needed. Methods Urethral N. gonorrhoeae isolates were collected from 684 men at public health clinics in California in 2011. Minimum inhibitory concentrations (MICs) to ceftriaxone, cefixime, cefpodoxime and azithromycin were determined by Etest and categorized according to the U.S. Centers for Disease Control 2010 alert value breakpoints. 684 isolates were screened for mosaic penA alleles using real-time PCR (RTPCR) and 59 reactive isolates were subjected to DNA sequencing of their penA alleles and Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST). To increase the specificity of the screening RTPCR in detecting isolates with alert value extended-spectrum cephalosporin MICs, the primers were modified to selectively amplify the mosaic XXXIV penA allele. Results Three mosaic penA alleles were detected including two previously described alleles (XXXIV, XXXVIII) and one novel allele (LA-A). Of the 29 isolates with an alert value extended-spectrum cephalosporin MIC, all possessed the mosaic XXXIV penA allele and 18 were sequence type 1407, an internationally successful strain associated with multi-drug resistance. The modified RTPCR detected the mosaic XXXIV penA allele in urethral isolates and urine specimens and displayed no amplification of the other penA alleles detected in this study. Conclusion N. gonorrhoeae isolates with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins are currently circulating in California. Isolates with the same NG-MAST ST, penA allele and extended-spectrum cephalosporin MICs have caused treatment failures elsewhere. The RTPCR assay presented here may be useful for the detection of N. gonorrheoae isolates and clinical specimens with reduced extended-spectrum cephalosporin MICs in settings where antimicrobial susceptibility testing is unavailable. In an era of increasing antimicrobial resistance and decreasing culture capacity, molecular assays capable of detecting extended-spectrum cephalosporin of resistance are essential to public health. PMID:24305088

2013-01-01

197

Comparative kinetic analysis on thermal degradation of some cephalosporins using TG and DSC data  

PubMed Central

Background The thermal decomposition of cephalexine, cefadroxil and cefoperazone under non-isothermal conditions using the TG, respectively DSC methods, was studied. In case of TG, a hyphenated technique, including EGA, was used. Results The kinetic analysis was performed using the TG and DSC data in air for the first step of cephalosporin’s decomposition at four heating rates. The both TG and DSC data were processed according to an appropriate strategy to the following kinetic methods: Kissinger-Akahira-Sunose, Friedman, and NPK, in order to obtain realistic kinetic parameters, even if the decomposition process is a complex one. The EGA data offer some valuable indications about a possible decomposition mechanism. The obtained data indicate a rather good agreement between the activation energy’s values obtained by different methods, whereas the EGA data and the chemical structures give a possible explanation of the observed differences on the thermal stability. A complete kinetic analysis needs a data processing strategy using two or more methods, but the kinetic methods must also be applied to the different types of experimental data (TG and DSC). Conclusion The simultaneous use of DSC and TG data for the kinetic analysis coupled with evolved gas analysis (EGA) provided us a more complete picture of the degradation of the three cephalosporins. It was possible to estimate kinetic parameters by using three different kinetic methods and this allowed us to compare the Ea values obtained from different experimental data, TG and DSC. The thermodegradation being a complex process, the both differential and integral methods based on the single step hypothesis are inadequate for obtaining believable kinetic parameters. Only the modified NPK method allowed an objective separation of the temperature, respective conversion influence on the reaction rate and in the same time to ascertain the existence of two simultaneous steps. PMID:23594763

2013-01-01

198

Methicillin-resistant Staphylococcus aureus Bacterial Nitric-oxide Synthase Affects Antibiotic Sensitivity  

E-print Network

Methicillin-resistant Staphylococcus aureus Bacterial Nitric-oxide Synthase Affects Antibiotic of Medicine, New York, New York 10016 Background: Methicillin-resistant Staphylococcus aureus (MRSA) generates activities to reduce MRSA pathology and increase antibiotic effectiveness. Staphylococcus aureus infections

Nizet, Victor

199

In vitro and in vivo antibacterial activities of S-1090, a new oral cephalosporin.  

PubMed Central

S-1090, a new oral cephalosporin, was active against selected gram-negative bacteria and methicillin-susceptible clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus warneri, against which it had excellent activity. S-1090 was the most active compound against Streptococcus pyogenes and Streptococcus agalactiae among the agents compared. The in vivo efficacy of S-1090 against systemic and urinary and respiratory tract infections caused by gram-positive and -negative bacteria was superior to that expected from the in vitro and in vivo activities of the agents against which it was compared. PMID:8585742

Tsuji, M; Ishii, Y; Ohno, A; Miyazaki, S; Yamaguchi, K

1995-01-01

200

Selectively Guanidinylated Aminoglycosides as Antibiotics  

PubMed Central

The emergence of virulent, drug-resistant bacterial strains coupled with a minimal output of new pharmaceutical agents to combat them makes this a critical time for antibacterial research. Aminoglycosides are a well-studied, highly potent class of naturally occurring antibiotics with scaffolds amenable to modification, and therefore, they provide an excellent starting point for the development of semisynthetic, next-generation compounds. To explore the potential of this approach, we synthesized a small library of aminoglycoside derivatives selectively and minimally modified at one or two positions with a guanidine group replacing the corresponding amine or hydroxy functionality. Most guanidino-aminoglycosides showed increased affinity for the ribosomal decoding rRNA site, the cognate biological target of the natural products, when compared with their parent antibiotics, as measured by an in vitro fluorescence resonance energy transfer (FRET) A-site binding assay. Additionally, certain analogues showed improved minimum inhibitory concentration (MIC) values against resistant bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA). An amikacin derivative holds particular promise with activity greater than or equal to the parent antibiotic in the majority of bacterial strains tested. PMID:22639134

Fair, Richard J.; Hensler, Mary E.; Thienphrapa, Wdee; Dam, Quang N.

2012-01-01

201

Evolution of an Antibiotic Resistance Enzyme Constrained by Stability and Activity Trade-offs  

SciTech Connect

Pressured by antibiotic use, resistance enzymes have been evolving new activities. Does such evolution have a cost? To investigate this question at the molecular level, clinically isolated mutants of the {beta}-lactamase TEM-1 were studied. When purified, mutant enzymes had increased activity against cephalosporin antibiotics but lost both thermodynamic stability and kinetic activity against their ancestral targets, penicillins. The X-ray crystallographic structures of three mutant enzymes were determined. These structures suggest that activity gain and stability loss is related to an enlarged active site cavity in the mutant enzymes. In several clinically isolated mutant enzymes, a secondary substitution is observed far from the active site (Met182 {yields} Thr). This substitution had little effect on enzyme activity but restored stability lost by substitutions near the active site. This regained stability conferred an advantage in vivo. This pattern of stability loss and restoration may be common in the evolution of new enzyme activity.

Wang, Xiaojun; Minasov, George; Shoichet, Brian K. (NWU)

2010-03-08

202

Environmental pollution by antibiotics and by antibiotic resistance determinants  

Microsoft Academic Search

Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can

Jose Luis Martinez

2009-01-01

203

ROTATING ANTIBIOTICS SELECTS OPTIMALLY AGAINST ANTIBIOTIC RESISTANCE, IN THEORY  

E-print Network

ROTATING ANTIBIOTICS SELECTS OPTIMALLY AGAINST ANTIBIOTIC RESISTANCE, IN THEORY R. E. BEARDMORE in an intensive care unit (ICU) will select against the evolution and spread of antibiotic-resistant pathogens the antibiotics are from distinct functional groups, we use a control theoretic-approach to prove that one can

Beardmore, Robert

204

Previous antibiotic exposure and evolution of antibiotic resistance in mechanically ventilated patients with  

E-print Network

Previous antibiotic exposure and evolution of antibiotic resistance in mechanically ventilated, Taichung, Taiwan Keywords: Antibiotic resistance; Antibiotic exposure; Antibiotic selection pressure; Antibiotic stewardship; Nosocomial infection Abstract Purpose: This study aimed to evaluate the impact

Cochran-Stafira, D. Liane

205

Sorption Mechanisms of Antibiotic Cephapirin onto Quartz and Feldspar by Raman Spectroscopy  

SciTech Connect

Raman spectroscopy was used to investigate the sorption mechanisms of cephapirin (CHP), a veterinary antibiotic, onto quartz (SiO2) and feldspar (KAlSi3O8) at different pH values. Depending on the charge and surface properties of the mineral, different reaction mechanisms including electrostatic attraction, monodentate and bidentate complexation were found to be responsible for CHP sorption. The zwitterion (CHPo) adsorbs to a quartz(+) surface by electrostatic attraction of the carboxylate anion group ( COO-) at a low pH, but adsorbs to a quartz(-) surface through electrostatic attraction of the pyridinium cation and possibly COO- bridge complexes at relatively higher pH conditions. CHP- bonds to a quartz(-) surface by bidentate complexation between one oxygen of COO- and oxygen from the carbonyl (C=O) of the acetoxymethyl group. On a feldspar surface of mixed charge, CHPo forms monodentate complexes between C=O as well as COO- bridging complexes or electrostatically attached to localized edge (hydr)oxy-Al surfaces. CHP- adsorbs to feldspar(-) through monodentate C=O complexation, and similar mechanisms may operate for the sorption of other cephalosporins. This research demonstrates, for the first time, that Raman spectroscopic techniques can be effective for evaluating the sorption processes and mechanisms of cephalosporin antibiotics even at relatively low sorbed concentrations (97-120 ?mol/kg).

Peterson, Jonathan [Hope College; Wang, Wei [ORNL; Gu, Baohua [ORNL

2009-01-01

206

Antibiotic susceptibility of bacteria isolated from respiratory tract of pigs in Poland between 2004 and 2008.  

PubMed

Antibiotic susceptibility of bacteria isolated from nasal swabs and lungs of pigs, to 16 commonly used antibiotics, was determined by disc diffusion test. beta-lactams showed the best activity against Streptococcus suis (S. suis) (> 99% of susceptible strains). The lowest sensitivity of S. suis was evidenced to: tylosin, tetracycline and neomycin (50%, 40% and 25%, respectively). Isolates of Escherichia coli (E. coli) demonstrated the highest susceptibility to cephalosporin (85% strains), gentamicin and norfloxacin (over 74%). The lowest susceptibility of E. coli was demonstrated to tiamulin and penicillin (11.3% and 1.9%, respectively). Over 80% of Actinobacillus pleuropneumoniae (App) strains were susceptible to all antibiotics tested. The highest resistance of App, but demonstrated by below 20% of tested isolates only, was evidenced to neomycin and LxS. Isolates of Pasteurella multocida (Pm), Haemophilus parasuis (Hps) and Arcanobacterium pyogenes (A. pyogenes) were highly susceptible to the most antibiotics included in the analysis. The comparison of the in vitro susceptibility of pathogens to the chemotherapeutics used on Polish farms for the therapy of bacterial infection of pigs within the last five years and the last 10 years, showed an increasing percent of E. coli and S. suis strains resistant to commonly used antibiotics. It is also shown that Pm, Hps, App and A. pyogenes isolates were continuously susceptible to the most chemotherapeutics applied. PMID:21077428

Markowska-Daniel, I; Urbaniak, K; Stepniewska, K; Pejsak, Z

2010-01-01

207

Antibiotics and Sinusitis  

MedlinePLUS

... duration. In patients that are healthy, high dose amoxicillin is the preferred antibiotic. If there is no ... of life. Pediatric Sinusitis In children, high dose amoxicillin, cefuroxime or amoxicillin with clavulanate are recommended especially ...

208

Antibiotic Prescriptions for Kids  

MedlinePLUS Videos and Cool Tools

... 15, 2014 Related MedlinePlus Pages Antibiotics Bacterial Infections Children's Health Viral Infections Transcript What's the best treatment when your child has an acute respiratory tract infection? We're ...

209

Meta-Analysis of Antibiotics and the Risk of Community-Associated Clostridium difficile Infection  

PubMed Central

The rising incidence of Clostridium difficile infection (CDI) could be reduced by lowering exposure to high-risk antibiotics. The objective of this study was to determine the association between antibiotic class and the risk of CDI in the community setting. The EMBASE and PubMed databases were queried without restriction to time period or language. Comparative observational studies and randomized controlled trials (RCTs) considering the impact of exposure to antibiotics on CDI risk among nonhospitalized populations were considered. We estimated pooled odds ratios (OR) for antibiotic classes using random-effect meta-analysis. Our search criteria identified 465 articles, of which 7 met inclusion criteria; all were observational studies. Five studies considered antibiotic risk relative to no antibiotic exposure: clindamycin (OR = 16.80; 95% confidence interval [95% CI], 7.48 to 37.76), fluoroquinolones (OR = 5.50; 95% CI, 4.26 to 7.11), and cephalosporins, monobactams, and carbapenems (CMCs) (OR = 5.68; 95% CI, 2.12 to 15.23) had the largest effects, while macrolides (OR = 2.65; 95% CI, 1.92 to 3.64), sulfonamides and trimethoprim (OR = 1.81; 95% CI, 1.34 to 2.43), and penicillins (OR = 2.71; 95% CI, 1.75 to 4.21) had lower associations with CDI. We noted no effect of tetracyclines on CDI risk (OR = 0.92; 95% CI, 0.61 to 1.40). In the community setting, there is substantial variation in the risk of CDI associated with different antimicrobial classes. Avoidance of high-risk antibiotics (such as clindamycin, CMCs, and fluoroquinolones) in favor of lower-risk antibiotics (such as penicillins, macrolides, and tetracyclines) may help reduce the incidence of CDI. PMID:23478961

Khanafer, Nagham; Daneman, Nick; Fisman, David N.

2013-01-01

210

Antibiotic-Induced Anaphylaxis  

Microsoft Academic Search

\\u000a An antibiotic allergic reaction represents one of the side effects of drugs and is a daily worry for the clinician. If urticaria\\u000a and maculo–papular eruptions are the most frequent manifestations, then anaphylaxis can occur. The tools allowing a definite\\u000a diagnosis are validated for some antibiotics and include the following procedures: a thorough clinical history, standardized\\u000a skin tests, reliable biological tests,

Pascal Demoly; Philippe Jean Bousquet; Antonino Romano

211

Eight more ways to deal with antibiotic resistance.  

PubMed

The fight against antibiotic resistance must be strengthened. We propose actions that U.S. government agencies and private sector entities can take to build a more comprehensive effort. These actions can increase the viability of investing in new antibiotics, ensure the quality and stewardship of all antibiotics, and make responses to emerging resistance more informed. Success requires the thoughtful exercise of federal authority and a firm commitment to share data and reward developers for the value generated with new, life-saving antibiotics. PMID:24867992

Metz, Matthew; Shlaes, David M

2014-08-01

212

[The history of antibiotics].  

PubMed

The development of chemical compounds for the treatment of infectious diseases may be divided into three phases: a) the discovery in the 1600s in South America of alkaloid extracts from the bark of the cinchona tree and from the dried root of the ipecacuanha bush, which proved effective against, respectively, malaria (quinine) and amoebic dysentery (emetine); b) the development of synthetic drugs, which mostly took place in Germany, starting with Paul Ehrlich's (1854-1915) discovery of salvarsan (1909), and crowned with Gerhard Domagk's (1895-1964) discovery of the sulfonamides (1930s); and c) the discovery of antibiotics. The prime example of the latter is the development of penicillin in the late 1920s following a discovery by a solitary research scientist who never worked in a team and never as part of a research programme. It took another ten years or so before drug-quality penicillin was produced, with research now dependent on being conducted in large collaborative teams, frequently between universities and wealthy industrial companies. The search for new antibiotics began in earnest in the latter half of the 1940s and was mostly based on soil microorganisms. Many new antibiotics were discovered in this period, which may be termed «the golden age of antibiotics». Over the past three decades, the development of new antibiotics has largely stalled, while antibiotic resistance has increased. This situation may require new strategies for the treatment of infectious diseases. PMID:24326504

Yazdankhah, Siamak; Lassen, Jørgen; Midtvedt, Tore; Solberg, Claus Ola

2013-12-10

213

Antibiotics produced by Streptomyces.  

PubMed

Streptomyces is a genus of Gram-positive bacteria that grows in various environments, and its shape resembles filamentous fungi. The morphological differentiation of Streptomyces involves the formation of a layer of hyphae that can differentiate into a chain of spores. The most interesting property of Streptomyces is the ability to produce bioactive secondary metabolites, such as antifungals, antivirals, antitumorals, anti-hypertensives, immunosuppressants, and especially antibiotics. The production of most antibiotics is species specific, and these secondary metabolites are important for Streptomyces species in order to compete with other microorganisms that come in contact, even within the same genre. Despite the success of the discovery of antibiotics, and advances in the techniques of their production, infectious diseases still remain the second leading cause of death worldwide, and bacterial infections cause approximately 17 million deaths annually, affecting mainly children and the elderly. Self-medication and overuse of antibiotics is another important factor that contributes to resistance, reducing the lifetime of the antibiotic, thus causing the constant need for research and development of new antibiotics. PMID:22975171

Procópio, Rudi Emerson de Lima; Silva, Ingrid Reis da; Martins, Mayra Kassawara; Azevedo, João Lúcio de; Araújo, Janete Magali de

2012-01-01

214

Non-Steroidal Anti-Inflammatory Drugs and Antibiotics Prescription Trends at a Central West Bank Hospital  

PubMed Central

Objectives: We aimed to reliably describe the pattern of outpatient prescription of non-steroidal anti-inflammatory drugs (NSAIDs) and antibiotics (ATBs) at a central hospital in the West Bank, Palestine. Methods: This was a retrospective, cross-sectional study investigating a cohort of 2,208 prescriptions ordered by outpatient clinics and the emergency room over one year in Beit Jala Hospital in Bethlehem, West Bank. The orders were analysed for the rate and types of NSAIDs and ATBs utilised, and the appropriateness of these drugs to the diagnosis. Results: Of the total prescriptions, 410 contained NSAIDs (18.6%), including diclofenac (40.2%), low dose aspirin (23.9%), ibuprofen (17.8%) and indomethacin (15.1%). A minority of these prescriptions contained a combination of these agents (2.5%). Only one prescription contained cyclooxyeganse-2 inhibitors (0.2%). The appropriateness of NSAID use to the diagnosis was as follows: appropriate (58.3%), inappropriate (14.4%) and difficult to tell (27.3%). The rate of ATB use was 30.3% (669 prescriptions). The ATBs prescribed were amoxicillin (23.3%), augmentin (14.3%), quinolones (12.7%), first and second generation cephalosporins (9.4% and 12.7%, respectively) and macrolides (7.2%). ATB combinations were identified in 9.4%, with the most common being second-generation cephalopsorins and metronidazole (4.3%). Regarding the appropriateness of prescribing ATBs according to the diagnosis, it was appropriate in 44.8%, inappropriate in 20.6% and difficult to tell in 34.6% of the prescriptions. Conclusion: These findings revealed a relatively large number and inappropriate utilisation of ATBs and NSAIDs. An interventional programme needs to be adopted to reinforce physicians’ knowledge of the rational prescription of these agents. PMID:24273668

Tayem, Yasin I.; Qubaja, Marwan M.; Shraim, Riyad K.; Taha, Omar B.; Abu Shkheidem, Imadeddin A.; Ibrahim, Murad A.

2013-01-01

215

Aminoglycoside Kinases and Antibiotic Resistance  

Microsoft Academic Search

The evolution of antibiotic-resistant bacteria represents a serious public health concern. The appearance of strains with\\u000a resistance to multiple antibiotics threatens to render some infections untreatable by existing drugs. As a result, there is\\u000a considerable interest in understanding the mechanisms of antibiotic resistance and in identifying ways in which antibiotic\\u000a resistance can be overcome. Aminoglycoside antibiotics are broad-spectrum bactericidal compounds

D. H. Fong; D. Burk; A. Berghuis

216

Aspergillomarasmine A overcomes metallo-?-lactamase antibiotic resistance.  

PubMed

The emergence and spread of carbapenem-resistant Gram-negative pathogens is a global public health problem. The acquisition of metallo-?-lactamases (MBLs) such as NDM-1 is a principle contributor to the emergence of carbapenem-resistant Gram-negative pathogens that threatens the use of penicillin, cephalosporin and carbapenem antibiotics to treat infections. To date, a clinical inhibitor of MBLs that could reverse resistance and re-sensitize resistant Gram-negative pathogens to carbapenems has not been found. Here we have identified a fungal natural product, aspergillomarasmine A (AMA), that is a rapid and potent inhibitor of the NDM-1 enzyme and another clinically relevant MBL, VIM-2. AMA also fully restored the activity of meropenem against Enterobacteriaceae, Acinetobacter spp. and Pseudomonas spp. possessing either VIM or NDM-type alleles. In mice infected with NDM-1-expressing Klebsiella pneumoniae, AMA efficiently restored meropenem activity, demonstrating that a combination of AMA and a carbapenem antibiotic has therapeutic potential to address the clinical challenge of MBL-positive carbapenem-resistant Gram-negative pathogens. PMID:24965651

King, Andrew M; Reid-Yu, Sarah A; Wang, Wenliang; King, Dustin T; De Pascale, Gianfranco; Strynadka, Natalie C; Walsh, Timothy R; Coombes, Brian K; Wright, Gerard D

2014-06-26

217

SCE-963, a New Potent Cephalosporin with High Affinity for Penicillin-Binding Proteins 1 and 3 of Escherichia coli  

PubMed Central

A few biochemical activities of SCE-963, a new cephalosporin with potent antibacterial activities against gram-negative bacteria, were compared with those of several currently available cephalosporins against strains of Escherichia coli K-12. The minimum inhibitory concentrations of SCE-963, cefazolin, cephaloridine, cephalothin, and cephalexin were 0.2, 1.56, 3.13, 12.5, and 25 ?g/ml, respectively. Affinities of these cephalosporins for the penicillin-binding protein (PBP) 1B of E. coli correlated well with their antibacterial activities; among tested cephalosporins, SCE-963 showed the highest affinity for PBP 1B. SCE-963 inhibited cross-linking of peptidoglycan in a cell-free system the most strongly suggesting that this inhibition results from its high affinity for PBP 1B. SCE-963 also showed the highest affinity for PBP 3; it caused filamentation of cells over a wide range of relatively lower concentrations. Thus its superior antibacterial activity is believed to be manifested through its high affinity for the PBPs. Images PMID:371539

Nozaki, Yukimasa; Imada, Akira; Yoneda, Masahiko

1979-01-01

218

Antibiotic Prescriptions in Critically-Ill Patients: A Latin American Experience  

PubMed Central

Background: It is widely acknowledged that the presence of infection is an important outcome determinant for intensive care unit (ICU) patients. In fact, antibiotics are one of the most common therapies administered in the ICU settings. Aim: To evaluate the current usage of antibiotics in Latin American ICUs. Subjects and Methods: A one-day p-oint prevalence study to investigate the patterns of antibiotic was undertaken in 72 Latin American (LA) ICUs. Data was analyzed using the Statistix 8 statistical software, version 2.0 (USA). Results were expressed as proportions. When applicable, two tailed hypothesis testing for difference in proportions was used (Proportion Test); a P value of <0.05 was considered significant. Results: Of 704 patients admitted, 359 received antibiotic treatment on the day of the study (51%), of which 167/359 cases (46.5%) were due to hospital-acquired infections. The most frequent infection reorted was nosocomial pneumonia (74/359, 21%). Only in 264/359 patients (73.5%), cultures before starting antibiotic treatment were performed. Thirty-eight percent of the isolated microorganisms were Enterobacteriaceae extended-spectrum ?-lactamase-producing, 11% methicillin-resistant Staphylococcus aureus and 10% carbapenems-resistant non-fermentative Gram-negatives. The antibiotics most frequently prescribed were carbapenems (125/359, 35%), alone or in combination with vancomycin or other antibiotic. There were no significant differences in the “restricted” antibiotic prescription (carbapenems, vancomycin, piperacillin–tazobactam, broad-spectrum cephalosporins, fluoroquinolones, tigecycline and linezolid) between patients with APACHE II score at the beginning of the antibiotic treatment <15 [83/114 (72.5%)] and ?15 [179/245 (73%)] (P = 0.96). Only 29% of the antibiotic treatments were cultured directed (104/359). Conclusion: Carbapenems (alone or in combination) were the most frequently prescribed antibiotics in LA ICUs. However, the problem of carbapenem resistance in LA requires that physicians improve the use of this class of antibiotics. Our findings show that our web-based method for collection of one-day point prevalence was implemented successfully. However, based on the limitations of the model used, the results of this study must be taken with caution. PMID:23919194

Curcio, D

2013-01-01

219

The multifaceted roles of antibiotics and antibiotic resistance in nature  

PubMed Central

Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic-resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic resistance in pathogens. In the natural milieu, antibiotics are often found to be present in sub-inhibitory concentrations acting as signaling molecules supporting the process of quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host–parasite interactions (e.g., phagocytosis, adherence to the target cell, and so on). The evolutionary and ecological aspects of antibiotics and antibiotic resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behavior of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and the genes that confer resistance to antibiotics in nature. PMID:23487476

Sengupta, Saswati; Chattopadhyay, Madhab K.; Grossart, Hans-Peter

2013-01-01

220

Antibiotics and perioperative infections.  

PubMed

Surgical site infections remain a significant contributor to postoperative morbidity and mortality. It is estimated that 500,000 patients suffer from this complication annually. Among other interventions, appropriate administration of prophylactic antibiotics has been shown to decrease the risk of perioperative infections. The goal of prophylactic antibiotic administration is to decrease the risk of contamination of the wound from skin flora in the case of clean procedures, and to add coverage of organisms that are anticipated to contaminate the surgical field, as in open bowel procedures. The purpose of this review is to summarize the guiding principles of perioperative antibiotic administration including selection, timing, redosing, and discontinuation. In addition, special topics including likely organisms for classes of surgical procedures, endocarditis prophylaxis, and management strategies for patients with allergies will be reviewed. PMID:18831304

James, Michael; Martinez, Elizabeth A

2008-09-01

221

Identification of multiple clones of extended-spectrum cephalosporin-resistant Streptococcus pneumoniae isolates in the United States.  

PubMed Central

We characterized 12 isolates of Streptococcus pneumoniae with various levels of susceptibility of penicillin and extended-spectrum cephalosporins by antimicrobial susceptibility patterns, serotypes, ribotypes, chromosomal DNA restriction patterns by pulsed-field gel electrophoresis, multilocus enzyme electrophoresis patterns, penicillin-binding protein (PBP) profiles, and DNA restriction endonuclease cleavage profiles of pbp1a, pbp2x, and pbp2b. Seven cefotaxime-resistant (MIC, > or = 2 micrograms/ml) serotype 23F isolates were related on the basis of ribotyping, pulsed-field gel electrophoresis, and multilocus enzyme electrophoresis, but they had two slightly different PBP patterns: one unique to strains for which the MIC of penicillin is high (4.0 micrograms/ml) and one unique to strains for which the MIC of penicillin is low (0.12 to 1.0 micrograms/ml). The pbp1a and pbp2x fingerprints were identical for the seven isolates; however, the pbp2b fingerprints were different. An eighth serotype 23F isolate with high-level resistance to cephalosporins was not related to the other seven isolates by typing data but was a variant of the widespread, multiresistant serotype 23F Spanish clone. The PBP profiles and fingerprints of pbp1a, pbp2x, and pbp2b were identical to those of the Spanish clone isolate. An additional serotype 6B isolate with high-level resistance to cephalosporins had unique typing profiles and was unrelated to the serotype 23F cephalosporin-resistant isolates but was related on the basis of genetic typing methods to a second serotype 6B isolate that was cephalosporin susceptible. The serotype 6B isolates had different PBP profiles and fingerprints for pbp1a, but the fingerprints for pbp2x and pbp2b were the same. PMID:8619583

McDougal, L K; Rasheed, J K; Biddle, J W; Tenover, F C

1995-01-01

222

Penicillin and cephalosporin biosynthesis: mechanism of carbon catabolite regulation of penicillin production.  

PubMed

Penicillins and cephalosporins are synthesized by a series of enzymatic reactions that form the tripeptide delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine and convert this tripeptide into the final penicillin or cephalosporin molecules. One of the enzymes, isopenicillin N synthase has been crystallyzed and its active center identified. The three genes pcbAB, pcbC and penDE involved in penicillin biosynthesis are clustered in Penicillium chrysogenum, Aspergillus nidulans and Penicillium nalgiovense. Carbon catabolite regulation of penicillin biosynthesis is exerted by glucose and other easily utilizable carbon sources but not by lactose. The glucose effect is enhanced by high phosphate concentrations. Glucose represses the biosynthesis of penicillin by preventing the formation of the penicillin biosynthesis enzymes. Transcription of the pcbAB, pcbC and penDE genes of P. chrysogenum is strongly repressed by glucose and the repression is not reversed by alkaline pHs. Carbon catabolite repression of penicillin biosynthesis in A. nidulans is not mediated by CreA and the same appears to be true in P. chrysogenum. The first two genes of the penicillin pathway (pcbAB and pcbC) are expressed from a bidirectional promoter region. Analysis of different DNA fragments of this bidirectional promoter region revealed two important DNA sequences (boxes A and B) for expression and glucose catabolite regulation of the pcbAB gene. Using protein extracts from mycelia grown under carbon catabolite repressing or derepressing conditions DNA-binding proteins that interact with the bidirectional promoter region were purified to near homogeneity. PMID:10422579

Martín, J F; Casqueiro, J; Kosalková, K; Marcos, A T; Gutiérrez, S

1999-01-01

223

Monitoring and identifying antibiotic resistance mechanisms in bacteria.  

PubMed

Sub-therapeutic administration of antibiotics to animals is under intense scrutiny because they contribute to the dissemination of antibiotic-resistant bacteria into the food chain. Studies suggest that there is a link between the agricultural use of antibiotics and antibiotic-resistant human infections. Antibiotic-resistant organisms from animal and human wastes reenter the human and animal populations through a number of pathways including natural waters, irrigation water, drinking water, and vegetables and foods. Antibiotic usage in the United States for animal production (disease prevention and growth promotion) is estimated to be 18 million pounds annually. As much as 25 to 75% of the antibiotics administered to feedlot animals are excreted unaltered in feces. Because about 180 million dry tons of livestock and poultry waste is generated annually in the United States, it is not surprising that animal-derived antibiotic-resistant organisms are found contaminating groundwater, surface water, and food crops. It is extremely important to clearly understand the molecular mechanisms that could potentially cause lateral or horizontal gene transfer of antibiotic resistance genes among bacteria. Once the mechanisms and magnitude of resistance gene transfer are clearly understood and quantified, strategies can be instituted to reduce the potential for dissemination of these genes. PMID:12710483

Roe, M T; Pillai, S D

2003-04-01

224

Tackling antibiotic resistance  

PubMed Central

The development and spread of antibiotic resistance in bacteria is a universal threat to both humans and animals that is generally not preventable, but can nevertheless be controlled and must be tackled in the most effective ways possible. To explore how the problem of antibiotic resistance might best be addressed, a group of thirty scientists from academia and industry gathered at the Banbury Conference Centre in Cold Spring Harbor, New York, May 16-18, 2011. From these discussions emerged a priority list of steps that need to be taken to resolve this global crisis. PMID:22048738

Bush, Karen; Courvalin, Patrice; Dantas, Gautam; Davies, Julian; Eisenstein, Barry; Huovinen, Pentti; Jacoby, George A.; Kishony, Roy; Kreiswirth, Barry N.; Kutter, Elizabeth; Lerner, Stephen A.; Levy, Stuart; Lewis, Kim; Lomovskaya, Olga; Miller, Jeffrey H.; Mobashery, Shahriar; Piddock, Laura J. V.; Projan, Steven; Thomas, Christopher M.; Tomasz, Alexander; Tulkens, Paul M.; Walsh, Timothy R.; Watson, James D.; Witkowski, Jan; Witte, Wolfgang; Wright, Gerry; Yeh, Pamela; Zgurskaya, Helen I.

2014-01-01

225

Antibiotics in Animal Products  

NASA Astrophysics Data System (ADS)

The administration of antibiotics to animals to prevent or treat diseases led us to be concerned about the impact of these antibiotics on human health. In fact, animal products could be a potential vehicle to transfer drugs to humans. Using appropri ated mathematical and statistical models, one can predict the kinetic profile of drugs and their metabolites and, consequently, develop preventive procedures regarding drug transmission (i.e., determination of appropriate withdrawal periods). Nevertheless, in the present chapter the mathematical and statistical concepts for data interpretation are strictly given to allow understanding of some basic pharma-cokinetic principles and to illustrate the determination of withdrawal periods

Falcão, Amílcar C.

226

Health Care Competition, Antibiotic Use, and Antibiotic Resistance in Taiwan  

Microsoft Academic Search

While antibiotics are critical to modern health care, their overuse has fostered an- tibiotic resistance. Since patients in many settings prefer to visit doctors who freely prescribe antibiotics, doctors may have an incentive to attract patients through greater prescription. This paper examines the eect of health care competition on antibiotic prescription in a large, nationally-representative sample of outpatient visits from

Daniel Bennett; Tsai-Ling Lauderdale; Che-Lun Hung

227

What is the optimum antibiotic prophylaxis in patients undergoing implantation of a left ventricular assist device?  

PubMed

A best evidence topic was written according to a structured protocol. The question addressed was what the optimum antibiotic prophylaxis in patients undergoing implantation of a left ventricular assist device (LVAD) is. A total of 373 papers were found, of which 11 represented the best evidence. The authors, date, journal, study type, population, main outcome measures and results are tabulated. Eight retrospective and two prospective studies, including one randomized controlled trial (RCT), were identified. Although highly variable, the prophylactic antibiotic protocols employed in these studies generally favour the use of vancomycin, a cephalosporin, beta-lactam and quinolone, with the option of additional fluconazole and mupirocin. However, the lack of standardized definitions for infection, and variations in the choice, timing and duration of prophylactic antibiotics complicates the interpretation of reported infection rates. Driveline and pocket infections comprised the majority of infectious complications, and were principally attributed to Gram-positive organisms, such as Staphylococcus, as well as Pseudomonas species. We conclude that a beta-lactam be used for primary prophylaxis, with vancomycin where the risk of MRSA is high. Topical mupirocin and an anti-fungal are also recommended. Prophylaxis should commence prior to device insertion, and be continued into the peri- and post-operative period. Large-scale RCTs are necessary to assess the impact of different antibiotic regimens on infection within LVAD recipients. PMID:22159247

Acharya, Metesh Nalin; Som, Robin; Tsui, Steven

2012-02-01

228

Prevalence, antibiotic resistance, and molecular characterization of Salmonella serovars in retail meat products.  

PubMed

The prevalence of Salmonella was determined in chicken meat (n = 26), beef (n = 49), and pork (n = 56) collected from wholesale markets, retail stores, and traditional markets in Seoul, South Korea, in 2009. Antibiotic resistance was assessed, and the molecular subtypes of Salmonella isolates were ascertained using an automated repetitive sequence-based PCR (rep-PCR) system (DiversiLab). A total of 18 Salmonella strains were isolated from 17 of 131 samples: 16 strains from each of 16 samples and 2 strains from the same pork sample. The prevalence of Salmonella from the retail meats was 2.0% in beef, 8.9% in pork, and 42.3% in chicken meat. Among 10 different serotypes, Salmonella enterica Panama was recovered from a beef sample, and Salmonella London and Salmonella Montevideo were the predominant serotypes from pork and chicken meat, respectively. The highest antibiotic resistance observed was to erythromycin (100%) followed by streptomycin (22.2%) and tetracycline and chloramphenicol (16.7%). Of the 18 isolates, 5 (27.8%) were resistant to two or more antibiotics, and 1 isolate from chicken meat was resistant to eight antibiotics, including cephalosporins. Differentiation between all of the Salmonella isolates except between Salmonella Montevideo and Salmonella London was successfully performed with the automated rep-PCR system, indicating that it can be added to the toolbox for source tracking of foodborne pathogens associated with outbreaks. PMID:21219782

Hyeon, Ji-Yeon; Chon, Jung-Whan; Hwang, In-Gyun; Kwak, Hyo-Sun; Kim, Moo-Sang; Kim, Soo-Ki; Choi, In-Soo; Song, Chang-Seon; Park, Chankyu; Seo, Kun-Ho

2011-01-01

229

Best antibiotics for buccal delivery  

E-print Network

The purpose of the research was to identify the clinical and commercial benefits of switching from intravenous (IV) to buccal delivery of antibiotics. then, the research continued to select 3-5 antibiotics that best met ...

Goldberg, Manijeh Nazari

2011-01-01

230

Antibiotic-Resistant Gonorrhea (ARG)  

MedlinePLUS

... gov . Gonorrhea Sexually Transmitted Diseases Gonorrhea Share Compartir Antibiotic-Resistant Gonorrhea Basic Information On this Page Surveillance Trends Challenges Laboratory Issues The development of antibiotic resistance in Neisseria gonorrhoeae is an urgent public ...

231

Self-medication with antibiotics.  

E-print Network

?? Background: Self-medication with antibiotics is a global phenomenon and potentialcontributor to human pathogen resistance to antibiotics. Amongst Pakistanis, antibioticself-medication rates are high. At present,… (more)

Khan, Rizwan Ahmad

2011-01-01

232

Bacterial cheating limits antibiotic resistance  

NASA Astrophysics Data System (ADS)

The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

2012-02-01

233

Evolution of antibiotic resistance  

Microsoft Academic Search

World-wide spread of bacterial resistance to antimicrobial agents may limit the future progress of medicine. A huge environmental antibiotic pressure, resulting from industrial production and marketing of these drugs, has simultaneously contributed to the increase in the diversity of resistant phenotypes, to the selection of the fittest among them, and to the dispersal of resistance genes, which is expected to

Fernando Baquero; Jesús Blázquez

1997-01-01

234

Antibiotic resistance: an overview  

Microsoft Academic Search

The results of large scale surveys have indicated that in general terms antibiotic resistance in bacteria has not increased, especially in Europe and North America. When the prevalence of resistance in specific bacteria has increased the increase has usually been associated with the introduction of a novel antimicrobial agent, whether in human or veterinary clinical practice, but the prevalence of

JR Walton

1988-01-01

235

Side effects of antibiotics  

Microsoft Academic Search

A review of the side effects of antibiotics in human patients is presented. At least three classes of untoward reactions may be distinguished: development of drug hypersensitivity, toxicological hazards, and microbial effects such as emergence of drug resistance.The intrinsic toxicities of the oldest discoveries, penicillin and sulphonamides, have turned out te be very low for most animals as well as

A. Manten

1981-01-01

236

Antibiotic Production by Soil Actinomycetes  

NSDL National Science Digital Library

Students attempt to identify Streptomycetes with antibiotic properties in local soil samples. The purpose of this investigation is to try to discover Actinomycetes from local soil samples that have antibiotic properties. The use of known species of Streptomycetes that produce antibiotics can be easily seen as they produce zones of inhibition on a lawn of bacteria; the antibiotic activity from local soil samples is variable and takes many samples to find a few that produce zones of inhibition.

John William Goudie (Kalamazoo Area Math and Science Center REV)

1995-06-30

237

Antibiotic use for common cold  

Microsoft Academic Search

Antibiotics do not help patients with an uncomplicated common cold. Antibiotics can have side effects for the individual taking\\u000a them that range from unpleasant to serious, even lethal. Antibiotic use also contributes to communal harm by encouraging antibiotic\\u000a resistance. If there can be no benefit, but there can be harm, why is the common cold the commonest reason for doctors

Timothy W. Kenealy; Bruce Arroll

238

Investigating the Antibiotic Resistance Problem.  

ERIC Educational Resources Information Center

Seeks to give teachers useful information on the extent of the problem of antibiotic-resistant bacteria, mechanisms bacteria use to resist antibiotics, the causes of the emergence of antibiotic-resistant organisms, and practices that can prevent or reverse this trend. Contains 19 references. (DDR)

Lawson, Michael; Lawson, Amy L.

1998-01-01

239

Antibiotics acting on the translational  

E-print Network

Antibiotics acting on the translational machinery Jörg M. Harms1,*, Heike Bartels1, Frank Schlünzen antibiotics, including vancomycin (the `last resort'), development of new antimicrobial agents has slowed during recent decades. To aid design of new antibiotics, we must develop a detailed understanding

Yonath, Ada E.

240

Antibiotic alternatives: the substitution of antibiotics in animal husbandry?  

PubMed Central

It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really replace antibiotics remains a controversial issue. This review summarizes recent development and perspectives of alternatives to antibiotics. The mechanism of actions, applications, and prospectives of the alternatives such as immunity modulating agents, bacteriophages and their lysins, antimicrobial peptides, pro-, pre-, and synbiotics, plant extracts, inhibitors targeting pathogenicity (bacterial quorum sensing, biofilm, and virulence), and feeding enzymes are thoroughly discussed. Lastly, the feasibility of alternatives to antibiotics is deeply analyzed. It is hard to conclude that the alternatives might substitute antibiotics in veterinary medicine in the foreseeable future. At the present time, prudent use of antibiotics and the establishment of scientific monitoring systems are the best and fastest way to limit the adverse effects of the abuse of antibiotics and to ensure the safety of animal-derived food and environment. PMID:24860564

Cheng, Guyue; Hao, Haihong; Xie, Shuyu; Wang, Xu; Dai, Menghong; Huang, Lingli; Yuan, Zonghui

2014-01-01

241

The abundance of antibiotic resistance genes in human guts has correlation to the consumption of antibiotics in animal.  

PubMed

Increasing evidence has accumulated to support that the human gut is a reservoir for antibiotic resistance genes. We previously identified more than 1000 genes displaying high similarity with known antibiotic resistance genes in the human gut gene set generated from the Chinese, Danish, and Spanish populations. Here, first, we add our new understanding of antibiotic resistance genes in the US and the Japanese populations; next, we describe the structure of a vancomycin-resistant operon in a Danish sample; and finally, we provide discussions on the correlation of the abundance of resistance genes in human gut with the antibiotic consumption in human medicine and in animal husbandry. These results, combined with those we published previously, provide comprehensive insights into the antibiotic resistance genes in the human gut microbiota at a population level. PMID:24637798

Hu, Yongfei; Yang, Xi; Lu, Na; Zhu, Baoli

2014-01-01

242

[Perioperative antibiotic prophylaxis].  

PubMed

In times of growing bacterial resistance against antimicrobiotic drugs the broad prescription of antibiotics in human medicine must be carefully considered. The perioperative antibiotic treatment is in the center of that conflict. On the one hand an efficient pathogen reduction for the preemptive treatment of infectious complications is desired but on the other hand it is suspected that this promotes the selection of multiresistant pathogens which could lead to an increase of more complicated nosocomial infections. The aim of this article is a critical appraisal of this subject on the basis of the 2012 guidelines of the German working group of Hygiene in Hospital and Practice (AWMF) and the 2010 recommendations of the Paul-Ehrlich-Gesellschaft. PMID:24402512

Reutter, F; Reuter, D A; Hilgarth, H; Heilek, A M; Goepfert, M S; Punke, M A

2014-01-01

243

Co-occurrence of Antibiotic and Heavy Metal Resistance in K?z?l?rmak River Isolates.  

PubMed

Contamination of surface waters with antimicrobials has become an increasing public health concern because of the emergence of multi-resistant pathogens. For this reason, water samples collected from the K?z?l?rmak River-K?r?kkale, Turkey were analysed to learn more about the co-occurrence of heavy metal and antibiotic resistance in bacteria. Resistant profiles were determined by using 26 antibiotics and 17 heavy metals. Out of 290, 24 isolates with both heavy metal and antibiotic resistance were determined. Resistance to heavy metals including lead, tin, nickel, barium, aliminum, strontium, silver and lithium varied between 50 and 92 %. More than 50 % of the isolates showed resistance to cephalosporin, quinolone, sulfonamide and aminoglycoside type of antibiotics. The discharge of antimicrobials to water bodies may cause a combined effect of selection and co-selection towards resistant bacteria. Therefore, surface waters may be potential hot spots of the evolution of heavy metal- and antibiotic-resistant bacteria and require special scientific consideration. PMID:25257221

Icgen, Bulent; Yilmaz, Fadime

2014-12-01

244

Antibiotics from myxobacteria.  

PubMed

Covering: up to the end of 2013. Myxobacteria produce a vast range of structurally diverse natural products with prominent biological activities. Here, we provide a detailed description and judge the potential of all antibiotically active myxobacterial compounds as lead structures, pointing out their particularities and, if known, their mode of action. Thus, the review provides an overview of the potential of specific compounds, suitable for future investigations and possible clinical applications. PMID:24841474

Schäberle, Till F; Lohr, Friederike; Schmitz, Alexander; König, Gabriele M

2014-07-01

245

b-Lactamases Responsible for Resistance to Expanded-Spectrum Cephalosporins in Klebsiella pneumoniae, Escherichia coli, and Proteus mirabilis Isolates Recovered in South Africa  

Microsoft Academic Search

Although resistance to the expanded-spectrum cephalosporins among members of the family Enterobacteria- ceae lacking inducible b-lactamases occurs virtually worldwide, little is known about this problem among iso- lates recovered in South Africa. Isolates of Klebsiella pneumoniae, Escherichia coli, and Proteus mirabilis resistant to expanded-spectrum cephalosporins recovered from patients in various parts of South Africa over a 3-month period were investigated

J. D. D. PITOUT; K. S. THOMSON; N. D. HANSON; A. F. EHRHARDT; E. S. MOLAND; C. C. SANDERS

1998-01-01

246

Pneumococcal resistance to antibiotics.  

PubMed Central

The geographic distribution of pneumococci resistant to one or more of the antibiotics penicillin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline appears to be expanding, and there exist foci of resistance to chloramphenicol and rifampin. Multiply resistant pneumococci are being encountered more commonly and are more often community acquired. Factors associated with infection caused by resistant pneumococci include young age, duration of hospitalization, infection with a pneumococcus of serogroup 6, 19, or 23 or serotype 14, and exposure to antibiotics to which the strain is resistant. At present, the most useful drugs for the management of resistant pneumococcal infections are cefotaxime, ceftriaxone, vancomycin, and rifampin. If the strains are susceptible, chloramphenicol may be useful as an alternative, less expensive agent. Appropriate interventions for the control of resistant pneumococcal outbreaks include investigation of the prevalence of resistant strains, isolation of patients, possible treatment of carriers, and reduction of usage of antibiotics to which the strain is resistant. The molecular mechanisms of penicillin resistance are related to the structure and function of penicillin-binding proteins, and the mechanisms of resistance to other agents involved in multiple resistance are being elucidated. Recognition is increasing of the standard screening procedure for penicillin resistance, using a 1-microgram oxacillin disk. PMID:2187594

Klugman, K P

1990-01-01

247

In vitro and in vivo evaluation of Ro 09-1428, a new parenteral cephalosporin with high antipseudomonal activity.  

PubMed Central

Ro 09-1428, a new parenteral cephalosporin with a catechol moiety attached at position 7 of the cephalosporin ring, showed high in vitro activity against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, and Streptococcus pyogenes, with MICs for 90% of strains tested (MIC90s) of less than or equal to 0.39 micrograms/ml. Morganella morganii, Providencia rettgeri, Citrobacter freundii, Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae were inhibited with MIC90s of less than or equal to 3.13 micrograms/ml. Serratia marcescens was less susceptible to Ro 09-1428, with a MIC90 of 25 micrograms/ml. The most distinctive feature of Ro 09-1428 was its potent activity against Pseudomonas aeruginosa and Acinetobacter calcoaceticus, with MIC90s of 0.39 and 6.25 micrograms/ml, respectively. Most of the ceftazidime-resistant strains of P. aeruginosa, E. cloacae, and C. freundii were inhibited by Ro 09-1428, while those of S. marcescens were resistant at a concentration of 12.5 micrograms/ml. Ro 09-1428 was more active than ceftazidime against staphylococci. PBP 3 was the most sensitive target in E. coli and P. aeruginosa. The response to ferric iron in growth medium suggests that Ro 09-1428 may be taken up by transport mechanisms similar to those of other catechol cephalosporins. In accordance with its in vitro activity, Ro 09-1428 activity was equal to or greater than ceftazidime activity in efficacy against experimental septicemias in mice. The results indicate that Ro 09-1428 is a broad-spectrum cephalosporin with advantages over ceftazidime in its activity against P. aeruginosa, staphylococci, and ceftazidime-resistant strains of C. freundii and E. cloacae. PMID:1906261

Arisawa, M; Sekine, Y; Shimizu, S; Takano, H; Angehrn, P; Then, R L

1991-01-01

248

Rapid Detection of ?-Lactamase-Hydrolyzing Extended-Spectrum Cephalosporins in Enterobacteriaceae by Use of the New Chromogenic ?Lacta Test  

PubMed Central

The chromogenic ?Lacta test developed for the rapid detection of ?-lactamase-hydrolyzing extended-spectrum cephalosporins in Enterobacteriaceae revealed good performance with extended-spectrum ?-lactamase (ESBL) producers (97.5% true-positive results). However, false-negative results occurred with chromosomal AmpC hyperproducers and plasmid AmpC producers, whereas uninterpretable results were mostly due to VIM-1 carbapenemase producers and possibly low levels of expressed ESBLs. PMID:24574293

Morosini, Maria Isabel; Garcia-Castillo, Maria; Tato, Marta; Gijon, Desiree; Valverde, Aranzazu; Ruiz-Garbajosa, Patricia

2014-01-01

249

A novel sensor for cephalosporins based on electrocatalytic oxidation by poly(o-anisidine)\\/SDS\\/Ni modified carbon paste electrode  

Microsoft Academic Search

In this work for first time, the electrocatalytic oxidations of some cephalosporins were carried out by poly(o-anisidine)\\/SDS\\/Ni modified carbon paste electrode using cyclic voltammetry, chronoamperometry and chronocoulometry methods. At first, poly(o-anisidine) was formed by cyclic voltammetry in monomer solution containing sodium dodesyl sulfate (SDS), on carbon paste electrode surface. Then, Ni(II) ions were incorporated to electrode by immersion of the

Reza Ojani; Jahan-Bakhsh Raoof; Saeed Zamani

2010-01-01

250

Prevalence of Ambler class A ?-lactamases and ampC expression in cephalosporin-resistant isolates of Acinetobacter baumannii.  

PubMed

We examined the prevalence of various cephalosporins' resistance mechanisms in Acinetobacter baumannii clinical isolates. Phenotypic and molecular detection of Ambler classes A, B and D ?-lactamases was performed on 75 isolates. Clonal relatedness was defined using Repetitive Extragenic Palindromic PCR. PCR mapping was used to examine the linkage of insertion sequences and the ampC gene, and ampC expression was analyzed by TaqMan reverse transcriptase-PCR. Twenty-six (37%) isolates carried at least one of the blaPER-1 or blaTEM-1. Sixty-nine (98.5%) out of 70 cephalosporin-resistant isolates had insertions upstream of the ampC gene, of which 48 (69%) and 6 (8%) were identified as ISAba1and ISAba125, respectively. Higher level of expression was obtained in resistant isolates lacking ISAba1/ampC combination in comparison with that in positive ones. The ability to up-regulate the expression of ampC gene in association with different insertion elements has become an important factor in A. baumannii resistance to cephalosporins. PMID:23726148

Rezaee, Mohammad Ahangarzadeh; Pajand, Omid; Nahaei, Mohammad Reza; Mahdian, Reza; Aghazadeh, Mohammad; Ghojazadeh, Morteza; Hojabri, Zoya

2013-07-01

251

In Vitro Activities of Cephalosporins and Quinolones against Escherichia coli Strains Isolated from Diarrheic Dairy Calves  

PubMed Central

The in vitro activities of several cephalosporins and quinolones against 195 strains of Escherichia coli isolated from dairy calves affected by neonatal diarrhea were determined. One hundred thirty-seven of these strains produced one or more potential virulence factors (F5, F41, F17, cytotoxic necrotizing factor, verotoxin, and the eae gene), but the remaining 58 strains did not produce any of these factors. From 11 to 18% of the E. coli strains were resistant to cephalothin, nalidixic acid, enoxacin, and enrofloxacin. However, cefuroxime, cefotaxime, and cefquinome were highly effective against the E. coli isolates tested. Some significant differences (P < 0.05) in resistance to quinolones between the strains producing potential virulence factors and nonfimbriated, nontoxigenic, eae-negative strains were found. Thus, eae-positive, necrotoxigenic, and verotoxigenic (except for nalidixic acid) E. coli strains were significantly more sensitive to nalidixic acid, enoxacin, and enrofloxacin than nonfimbriated, nontoxigenic, eae-negative strains. Moreover, eae-positive strains were significantly more sensitive to enoxacin and enrofloxacin than F5-positive strains. Thus, the results of this study suggest that the bovine E. coli strains that produce some potential virulence factors are more sensitive to quinolones than those that do not express these factors. PMID:10049259

Orden, José Antonio; Ruiz-Santa-Quiteria, José Antonio; García, Silvia; Cid, Dolores; de la Fuente, Ricardo

1999-01-01

252

Advanced treatment of cephalosporin pharmaceutical wastewater by nano-coated electrode and perforated electrode.  

PubMed

The objective of this study was to investigate the degradation of nonbiodegradable organic pollutants in biologically cephalosporin pharmaceutical wastewater using different electrodes such as non-nano-scale electrode (traditional coated), nano-scale (nano-coated) electrode, and perforated electrode after biotreatment. The traditional coated electrode plate, nano-coated electrode plate, and two different perforated titanium dioxide (TiO2) electrode plates with an average pore size of 10 ?m and 20 ?m were chosen as the anode. The results demonstrated that traditional coated electrode, nano-scale electrode, and perforated electrode could effectively remove nonbiodegradable organic pollutants from pharmaceutical wastewater. The perforated electrode with an average pore size of 10 ?m exhibited the best degradation effect with a 90 % decrease in the chemical oxygen demand (COD) (COD content reduced from 320 mg L(-1) to 32 mg L(-1)). During catalytic degradation, the electrical conductivity of pharmaceutical wastewater increased and the pH increased and finally reached equilibrium. It was also found that the perforated TiO2 electrode produced relatively large amounts of dissolved oxygen during the catalytic oxidation process, reaching above 4 mg L(-1), whereas the nano-coated electrode produced little dissolved oxygen. The biotoxicities of all wastewater samples increased firstly then decreased slightly during the electrical catalytic oxidation, but the final biotoxicities were all higher than initial ones. PMID:24967559

Yang, Bo; Zuo, Jiane; Gan, Lili; Yu, Xin; Liu, Fenglin; Tang, Xinyao; Wang, Yajiao

2014-09-19

253

Use of oral cephalosporins in the treatment of acute otitis media in children  

Microsoft Academic Search

The selection of the most effective antimicrobial to treat acute otitis media (AOM) has become more difficult in recent years because of increasing antibiotic resistance among all AOM pathogens. Resistance of Streptococcus pneumoniae to penicillin as well as amoxicillin ranges from 30 to 55% in the USA. Currently, 40–55% of Haemophilus influenzae and 90–100% of Moraxella catarrhalis are resistant to

Itzhak Brook

2004-01-01

254

Role of prophylactic antibiotics in cirrhotic patients with variceal bleeding  

PubMed Central

Bacterial infections are common in cirrhotic patients with acute variceal bleeding, occurring in 20% within 48 h. Outcomes including early rebleeding and failure to control bleeding are strongly associated with bacterial infection. However, mortality from variceal bleeding is largely determined by the severity of liver disease. Besides a higher Child-Pugh score, patients with hepatocellular carcinoma are particularly susceptible to infections. Despite several hypotheses that include increased use of instruments, greater risk of aspiration pneumonia and higher bacterial translocation, it remains debatable whether variceal bleeding results in infection or vice versa but studies suggest that antibiotic prophylaxis prior to endoscopy and up to 8 h is useful in reducing bacteremia and spontaneous bacterial peritonitis. Aerobic gram negative bacilli of enteric origin are most commonly isolated from cultures, but more recently, gram positives and quinolone-resistant organisms are increasingly seen, even though their clinical significance is unclear. Fluoroquinolones (including ciprofloxacin and norfloxacin) used for short term (7 d) have the most robust evidence and are recommended in most expert guidelines. Short term intravenous cephalosporin (especially ceftriaxone), given in a hospital setting with prevalent quinolone-resistant organisms, has been shown in studies to be beneficial, particularly in high risk patients with advanced cirrhosis. PMID:24587656

Lee, Yeong Yeh; Tee, Hoi-Poh; Mahadeva, Sanjiv

2014-01-01

255

Chromosomal resistance to antibiotics in gonococci from Bahrain.  

PubMed

Ninety-one isolates of non-penicillinase-producing Neisseria gonorrhoeae from patients in Bahrain were tested for serotype, auxotype, and antibiotic susceptibility. Ten serovars and three auxotypes were found. Of the 91 isolates, 49 (54%) were serovar IB-5/7, 59 (65%) had a penicillin MIC greater than or equal to 1 mg/l, 39 (45%) had a cefuroxime MIC greater than or equal to 0.5 mg/l, and 63 (69%) had a tetracycline MIC of greater than or equal to 4 mg/l. No spectinomycin or high-level tetracycline resistance was seen. Seventy of the 91 isolates were tested against ciprofloxacin and ceftriaxone, and 40 (57%) and 26 (37%) had MICs greater than or equal to 0.03 mg/l, respectively. DNA from two penicillin-resistant isolates was capable of transforming recipient strain FA19 to donor level of penicillin and cephalosporin resistance in four steps. The first three steps were indicative of the acquisition of known resistance mutations. The existence of the fourth level transformants, with the ability of donor DNA to transform strain FA140 to higher levels of resistance, suggest the presence of another resistance mutation. PMID:1948513

Bindayna, K M; Easmon, C S; Ison, C A

1991-01-01

256

Use of antibiotics in bronchiectasis.  

PubMed

Bronchiectasis is defined by the presence of abnormal bronchial widening and occurs as a consequence of chronic airway infection. It is an important and common cause of respiratory disease. Antibiotics are the main therapy used for the treatment of this condition. The article will review the use of antibiotics for the treatment of bronchiectasis. Antibiotics can be given as short-term therapy for exacerbations or as long-term/maintenance therapy. Antibiotics given by the inhalational route and macrolides are two relatively new classes of medication that may be useful for long-term therapy. There are significant concerns about the overuse resulting in antibiotic resistance. It should be emphasized that nearly all of the trials in the literature have only had small numbers of subjects. The data that is available describing the use of antibiotics in bronchiectasis can generally be regarded as preliminary. PMID:22023177

King, Paul T; Holmes, Peter W

2012-02-01

257

Liquid antibiotics in bone cement  

PubMed Central

Objectives The objective of this study was to compare the elution characteristics, antimicrobial activity and mechanical properties of antibiotic-loaded bone cement (ALBC) loaded with powdered antibiotic, powdered antibiotic with inert filler (xylitol), or liquid antibiotic, particularly focusing on vancomycin and amphotericin B. Methods Cement specimens loaded with 2 g of vancomycin or amphotericin B powder (powder group), 2 g of antibiotic powder and 2 g of xylitol (xylitol group) or 12 ml of antibiotic solution containing 2 g of antibiotic (liquid group) were tested. Results Vancomycin elution was enhanced by 234% in the liquid group and by 12% in the xylitol group compared with the powder group. Amphotericin B elution was enhanced by 265% in the liquid group and by 65% in the xylitol group compared with the powder group. Based on the disk-diffusion assay, the eluate samples of vancomycin-loaded ALBC of the liquid group exhibited a significantly larger inhibitory zone than samples of the powder or the xylitol group. Regarding the ALBCs loaded with amphotericin B, only the eluate samples of the liquid group exhibited a clear inhibitory zone, which was not observed in either the xylitol or the powder groups. The ultimate compressive strength was significantly reduced in specimens containing liquid antibiotics. Conclusions Adding vancomycin or amphotericin B antibiotic powder in distilled water before mixing with bone cement can significantly improve the efficiency of antibiotic release than can loading ALBC with the same dose of antibiotic powder. This simple and effective method for preparation of ALBCs can significantly improve the efficiency of antibiotic release in ALBCs. Cite this article: Bone Joint Res 2014;3:246–51. PMID:25104836

Chang, Y. H.; Tai, C. L.; Hsu, H. Y.; Hsieh, P. H.; Lee, M. S.; Ueng, S. W. N.

2014-01-01

258

Antibiotic overuse versus chronic suppression  

Microsoft Academic Search

Because of the increasing use of antibiotics in the inpatient and outpatient setting, the emergence of resistance to antimicrobial\\u000a agents has progressed significantly. Traditionally, antibiotic resistance has been a problem only in the management of complicated\\u000a nosocomial urinary tract infections (UTIs). However, we now are seeing an emergence of antibiotic resistance in uncomplicated\\u000a community-acquired UTIs. Although uncomplicated UTIs constitute most

Kevin Bigelow; Alexis E. Te

2005-01-01

259

A prospective study on Adverse Drug Reactions of antibiotics in a tertiary care hospital  

PubMed Central

Adverse reactions are the recognized hazards of drug therapy and they can occur with any class of drugs and many studies revealed that the incidence is more in case of antibiotics. The main aim of this study was to detect and analyze Adverse Drug Reactions of antibiotics in inpatients of a tertiary care hospital. A prospective spontaneous reporting study by active and passive methods was carried out for a period of six months. A total of 49 ADRs were reported during the study period with male predominance (53.06%) and geriatric age group. More number of ADRs was from General Medicine and Pediatric departments in which the most affected organ systems were the GIT (38.77%) and the skin (30.61%). The antibiotic classes mostly accounted were cephalosporins (34.69%) followed by fluoroquinolones and others in which type A reactions were more compared to type B and 59.18% of them were predictable. The severity assessment revealed that most of them were moderate (63.26%) followed by mild and severe reactions. Of the reported reactions, 55.10% were definitely preventable and causality assessment was done which showed that 71.42% of the reactions were probable, possible (18.36%), definite (10.20%) and no reactions were unlikely. The study concluded that Adverse Drug Reactions to antibiotics are common and some of them resulted in increased healthcare cost due to the need of some interventions and increased length of hospital stay. The health system should promote the spontaneous reporting of Adverse Drug Reactions to antibiotics, proper documentation and periodic reporting to regional pharmacovigilance centers to ensure drug safety. PMID:25161373

Shamna, M.; Dilip, C.; Ajmal, M.; Linu Mohan, P.; Shinu, C.; Jafer, C.P.; Mohammed, Yahiya

2013-01-01

260

Combined administration of antibiotics and direct oral anticoagulants: a renewed indication for laboratory monitoring?  

PubMed

The recent development and marketing of novel direct oral anticoagulants (DOACs) represents a paradigm shift in the management of patients requiring long-term anticoagulation. The advantages of these compounds over traditional therapy with vitamin K antagonists include a reportedly lower risk of severe hemorrhages and the limited need for laboratory measurements. However, there are several scenarios in which testing should be applied. The potential for drug-to-drug interaction is one plausible but currently underrecognized indication for laboratory assessment of the anticoagulant effect of DOACs. In particular, substantial concern has been raised during Phase I studies regarding the potential interaction of these drugs with some antibiotics, especially those that interplay with permeability glycoprotein (P-gp) and cytochrome 3A4 (CYP3A4). A specific electronic search on clinical trials published so far confirms that clarithromycin and rifampicin significantly impair the bioavailability of dabigatran, whereas clarithromycin, erythromycin, fluconazole, and ketoconazole alter the metabolism of rivaroxaban in vivo. Because of their more recent development, no published data were found for apixaban and edoxaban, or for potential interactions of DOACs with other and widely used antibiotics. It is noteworthy, however, that an online resource based on Food and Drug Administration and social media information, reports several hemorrhagic and thrombotic events in patients simultaneously taking dabigatran and some commonly used antibiotics such as amoxicillin, cephalosporin, and metronidazole. According to these reports, the administration of antibiotics in patients undergoing therapy with DOACs would seem to require accurate evaluation as to whether dose adjustments (personalized or antibiotic class driven) of the anticoagulant drug may be advisable. This might be facilitated by direct laboratory assessments of their anticoagulant effect ex vivo. PMID:24919144

Lippi, Giuseppe; Favaloro, Emmanuel J; Mattiuzzi, Camilla

2014-10-01

261

Degradation kinetics and mechanism of ?-lactam antibiotics by the activation of H2O2 and Na2S2O8 under UV-254nm irradiation.  

PubMed

The extensive production and usage of antibiotics have led to an increasing occurrence of antibiotic residuals in various aquatic compartments, presenting a significant threat to both ecosystem and human health. This study investigated the degradation of selected ?-lactam antibiotics (penicillins: ampicillin, penicillin V, and piperacillin; cephalosporin: cephalothin) by UV-254nm activated H2O2 and S2O8(2-) photochemical processes. The UV irradiation alone resulted in various degrees of direct photolysis of the antibiotics; while the addition of the oxidants improved significantly the removal efficiency. The steady-state radical concentrations were estimated, revealing a non-negligible contribution of hydroxyl radicals in the UV/S2O8(2-) system. Mineralization of the ?-lactams could be achieved at high UV fluence, with a slow formation of SO4(2-) and a much lower elimination of total organic carbon (TOC). The transformation mechanisms were also investigated showing the main reaction pathways of hydroxylation (+16Da) at the aromatic ring and/or the sulfur atom, hydrolysis (+18Da) at the ?-lactam ring and decarboxylation (-44Da) for the three penicillins. Oxidation of amine group was also observed for ampicillin. This study suggests that UV/H2O2 and UV/S2O8(2-) advanced oxidation processes (AOPs) are capable of degrading ?-lactam antibiotics decreasing consequently the antibiotic activity of treated waters. PMID:25086235

He, Xuexiang; Mezyk, Stephen P; Michael, Irene; Fatta-Kassinos, Despo; Dionysiou, Dionysios D

2014-08-30

262

Antibiotic control of antibiotic resistance in hospitals: a simulation study  

Microsoft Academic Search

BACKGROUND: Using mathematical deterministic models of the epidemiology of hospital-acquired infections and antibiotic resistance, it has been shown that the rates of hospital-acquired bacterial infection and frequency of antibiotic infections can be reduced by (i) restricting the admission of patients colonized with resistant bacteria, (ii) increasing the rate of turnover of patients, (iii) reducing transmission by infection control measures, and

Michael J Haber; Bruce R Levin; Piotr Kramarz

2010-01-01

263

Microbes: Too Smart for Antibiotics?  

NSDL National Science Digital Library

This lesson focuses on examining why microbes become resistant to antibiotics, as well as their roles in human health and the environment. Students can produce public-awareness campaigns on antibiotic use, create yogurt recipe cards, develop a commercial bioremediation product, experiment with simulated germs and more!

Peggy Deichstetter (St. Edward High School;)

2002-12-01

264

Antibiotics: Opportunities for Genetic Manipulation  

Microsoft Academic Search

New antibiotics can still be discovered by the development of novel screening procedures. Notable successes over the last few years include the monobactams, beta-lactamase inhibitors (clavulanic acid) and new glycopeptides in the antibacterial field; antiparasitic agents such as avermectins; and herbicidal antibiotics like bialaphos. In the future we can expect the engineering of genes from 'difficult' pathogens, including mycobacteria and

D. A. Hopwood

1989-01-01

265

Multiple antibiotic resistance and efflux  

Microsoft Academic Search

Multiple antibiotic resistance in bacteria was at first thought to be caused exclusively by the combination of several resistance genes, each coding for resistance to a single drug. More recently, it became clear that such phenotypes are often achieved by the activity of drug efflux pumps. Some of these efflux pumps exhibit an extremely wide specificity covering practically all antibiotics,

Hiroshi Nikaido

1998-01-01

266

The Antibiotic Resistance Problem Revisited  

ERIC Educational Resources Information Center

The term "antibiotic" was first proposed by Vuillemin in 1889 but was first used in the current sense by Walksman in 1941. An antibiotic is defined as a "derivative produced by the metabolism of microorganisms that possess antibacterial activity at low concentrations and is not toxic to the host." In this article, the author describes how…

Lawson, Michael A.

2008-01-01

267

JAMA Patient Page: Inappropriate Use of Antibiotics  

MedlinePLUS

... Medical Association JAMA PATIENT PAGE Inappropriate Use of Antibiotics A n antibiotic is a substance produced naturally by microorganisms or ... infections. THESE INFECTIONS CAN USUALLY BE TREATED WITHOUT ANTIBIOTICS • Common cold • Influenza (flu) • Most coughs and bronchitis ( ...

268

Reducing fitness costs associated with antibiotic resistance  

E-print Network

Reducing fitness costs associated with antibiotic resistance Experimental evolution Reducing fitness costs associated with antibiotic resistance Experimental evolution in the filamentous;Schoustra, Sijmen Ecco Reducing fitness costs associated with antibiotic resistance ­ Experimental evolution

Kassen, Rees

269

Essential Oils, A New Horizon in Combating Bacterial Antibiotic Resistance  

PubMed Central

For many years, the battle between humans and the multitudes of infection and disease causing pathogens continues. Emerging at the battlefield as some of the most significant challenges to human health are bacterial resistance and its rapid rise. These have become a major concern in global public health invigorating the need for new antimicrobial compounds. A rational approach to deal with antibiotic resistance problems requires detailed knowledge of the different biological and non-biological factors that affect the rate and extent of resistance development. Combination therapy combining conventional antibiotics and essential oils is currently blooming and represents a potential area for future investigations. This new generation of phytopharmaceuticals may shed light on the development of new pharmacological regimes in combating antibiotic resistance. This review consolidated and described the observed synergistic outcome between essential oils and antibiotics, and highlighted the possibilities of essential oils as the potential resistance modifying agent. PMID:24627729

Yap, Polly Soo Xi; Yiap, Beow Chin; Ping, Hu Cai; Lim, Swee Hua Erin

2014-01-01

270

Cephalosporin MIC Distribution of Extended-Spectrum-?-Lactamase- and pAmpC-Producing Escherichia coli and Klebsiella Species?  

PubMed Central

The acquisition of ?-lactamases in members of the Enterobacteriaceae family poses a challenge to antimicrobial susceptibility testing in the clinical laboratory. We correlated the distribution of the MICs for Klebsiella spp. and Escherichia coli with the presence of extended-spectrum ?-lactamase (ESBL) and plasmid-mediated AmpC ?-lactamase (pAmpC) genes. A total of 264 isolates were subjected to cefazolin, ceftriaxone, cefotaxime, ceftazidime, cefepime, and aztreonam agar dilution MIC determination; ESBL screening and confirmatory testing by the methods of the Clinical and Laboratory Standards Institute (CLSI); and for isolates for which the MICs of extended-spectrum cephalosporins were ?1 ?g/ml or the MICs of cefpodoxime were >4 ?g/ml, PCR amplification and sequencing of the ESBL and pAmpC genes. PCR was positive for 73/81 isolates (45 isolates with an ESBL gene alone, 24 isolates with a pAmpC gene alone, with 4 isolates with both genes). Compared to PCR, confirmatory testing by the CLSI method yielded a sensitivity and a specificity of 98.0 and 96.3%, respectively; there were six false-positive results and one false-negative result. No distinction in the MIC distribution was apparent between isolates with the ESBL gene and isolates with the pAmpC gene. A substantial percentage of the isolates with PCR-confirmed ESBL and/or pAmpC genes fell within the current CLSI susceptible category. For a ceftazidime, ceftriaxone, or cefotaxime MIC of ?2 ?g/ml, a dichotomy existed between isolates with and without ESBL and pAmpC genes in most cases. This suggests that the presence of the ESBL and the pAmpC enzymes may yield similar MICs of extended-spectrum cephalosporins, many of which fall within the current nonresistant categories. Lowering of the current CLSI breakpoints for cephalosporins appears to be warranted. PMID:19494061

Kohner, Peggy C.; Robberts, Frans J. L.; Cockerill, Franklin R.; Patel, Robin

2009-01-01

271

Experimental Study of LY333328 (Oritavancin), Alone and in Combination, in Therapy of Cephalosporin-Resistant Pneumococcal Meningitis  

PubMed Central

Using a rabbit model of meningitis, we sought to determine the efficacy of LY333328, a semisynthetic glycopeptide, in the treatment of cephalosporin-resistant pneumococcal meningitis. LY333328 was administered at a dose of 10 mg/kg of body weight/day, alone and in combination with ceftriaxone at 100 mg/kg/day with or without dexamethasone at 0.25 mg/kg/day. The therapeutic groups were treated with LY333328 with or without dexamethasone and LY333328-ceftriaxone with or without dexamethasone. Rabbits were inoculated with a cephalosporin-resistant pneumococcal strain (ceftriaxone MIC, 2 ?g/ml; penicillin MIC, 4 ?g/ml; LY333328 MIC, 0.008 ?g/ml) and were treated over a 26-h period beginning 18 h after inoculation. The bacterial counts in cerebrospinal fluid (CSF), the white blood cell count, the lactic acid concentration, the CSF LY333328 concentration, and bactericidal and bacteriostatic activities were determined at different time points. In vitro, LY333328 was highly bactericidal and its use in combination with ceftriaxone at one-half the MIC was synergistic. In the rabbit model, LY333328 alone was an excellent treatment for cephalosporin-resistant pneumococcal meningitis, with a rapid decrease in colony counts and no therapeutic failures. The use of LY333328 in combination with ceftriaxone improved the activity of LY333328, but no synergistic effect was observed. The combination of LY333328 with dexamethasone was also rapidly bactericidal, but two therapeutic failures were observed. The combination of LY333328 with ceftriaxone and dexamethasone was effective, without therapeutic failures. PMID:12760866

Cabellos, Carmen; Fernandez, Antonio; Maiques, Jose M.; Tubau, Fe; Ardanuy, Carmen; Viladrich, Pedro F.; Linares, Josefina; Gudiol, Francesc

2003-01-01

272

Bacterial evolution of antibiotic hypersensitivity  

PubMed Central

The evolution of resistance to a single antibiotic is frequently accompanied by increased resistance to multiple other antimicrobial agents. In sharp contrast, very little is known about the frequency and mechanisms underlying collateral sensitivity. In this case, genetic adaptation under antibiotic stress yields enhanced sensitivity to other antibiotics. Using large-scale laboratory evolutionary experiments with Escherichia coli, we demonstrate that collateral sensitivity occurs frequently during the evolution of antibiotic resistance. Specifically, populations adapted to aminoglycosides have an especially low fitness in the presence of several other antibiotics. Whole-genome sequencing of laboratory-evolved strains revealed multiple mechanisms underlying aminoglycoside resistance, including a reduction in the proton-motive force (PMF) across the inner membrane. We propose that as a side effect, these mutations diminish the activity of PMF-dependent major efflux pumps (including the AcrAB transporter), leading to hypersensitivity to several other antibiotics. More generally, our work offers an insight into the mechanisms that drive the evolution of negative trade-offs under antibiotic selection. PMID:24169403

Lazar, Viktoria; Pal Singh, Gajinder; Spohn, Reka; Nagy, Istvan; Horvath, Balazs; Hrtyan, Monika; Busa-Fekete, Robert; Bogos, Balazs; Mehi, Orsolya; Csorgo, Balint; Posfai, Gyorgy; Fekete, Gergely; Szappanos, Balazs; Kegl, Balazs; Papp, Balazs; Pal, Csaba

2013-01-01

273

Improved perioperative antibiotic use and reduced surgical wound infections through use of computer decision analysis.  

PubMed

A prospective study was performed over a two-year period to determine whether computer-generated reminders of perioperative antibiotic use could improve prescribing habits and reduce postoperative wound infections. During the first year, baseline patterns of antibiotic use and postoperative infection rates were established. During the second year, computer-generated reminders regarding perioperative antibiotic use were placed in the patient's medical record prior to surgery and patterns of antibiotic use and postoperative wound infections monitored. Hospitalized patients undergoing non-emergency surgery from June to November 1985 (3,263 patients), and from June to November 1986 (3,568) were monitored with respect to indications for perioperative antibiotic use, timing of antibiotic use and postoperative infectious complications. Perioperative antibiotic use was considered advisable for 1,621 (50%) patients in the 1985 sample and for 1,830 (51%) patients in the 1986 sample. Among these patients, antibiotics were given within two hours before the surgical incision in 638 (40%) of the 1985 sample and 1,070 (58%) of the 1986 sample (p less than 0.001). Overall, postoperative wound infections were detected in 28 (1.8%) of 1,621 patients in 1985 compared with 16 (0.9%) of 1,830 such patients in 1986 (p less than 0.03). We conclude that computer-generated reminders of perioperative antibiotic use improved prescribing habits with a concurrent decline in postoperative wound infections. PMID:2745959

Larsen, R A; Evans, R S; Burke, J P; Pestotnik, S L; Gardner, R M; Classen, D C

1989-07-01

274

Antibiotic resistance in wild birds  

PubMed Central

Wild birds have been postulated as sentinels, reservoirs, and potential spreaders of antibiotic resistance. Antibiotic-resistant bacteria have been isolated from a multitude of wild bird species. Several studies strongly indicate transmission of resistant bacteria from human rest products to wild birds. There is evidence suggesting that wild birds can spread resistant bacteria through migration and that resistant bacteria can be transmitted from birds to humans and vice versa. Through further studies of the spatial and temporal distribution of resistant bacteria in wild birds, we can better assess their role and thereby help to mitigate the increasing global problem of antibiotic resistance. PMID:24697355

Bonnedahl, Jonas

2014-01-01

275

[Antibiotic prophylaxis and endoluminal tubes].  

PubMed

Surgical site infections are one of the most common complications after surgical procedures. The use of perioperative antibiotic prophylaxis can successfully reduce the number of wound infections. The indications, timing and choice of antibiotics are discussed critically. Taken together antibiotic prophylaxis should be evaluated depending on wound contamination, the type of operation and patient-specific risk factors. In the second part of this work the current literature on the effectiveness of endoluminal tubes in abdominal surgery is analyzed. While many surgeons use these tubes regularly in elective abdominal surgery, only few data are available on this topic. The use of nasogastric tubes in elective surgery should be avoided. PMID:22008844

Justinger, C; Schilling, M K

2011-12-01

276

Beta-lactam resistance in Aeromonas spp. caused by inducible beta-lactamases active against penicillins, cephalosporins, and carbapenems.  

PubMed Central

Use of cefoperazone in a patient with Aeromonas caviae in the respiratory tract selected a mutant that constitutively produced beta-lactamase. This mutant, in contrast to its parental strain with an inducible beta-lactamase, showed enhanced resistance to newer cephalosporins and aztreonam. This observation suggested that species of Aeromonas, like those of other genera with inducible beta-lactamases, may pose therapeutic problems associated with the rapid development of multiple beta-lactam resistance. Thus, a study was designed to identify the beta-lactamases in 12 strains representing four species of Aeromonas and assess their role in drug resistance. Eleven strains possessed inducible beta-lactamases. One strain showed no detectable activity. An analysis of substrate and inhibitor profiles, isoelectric points, and beta-lactam susceptibility patterns revealed the presence of at least four distinguishable inducible beta-lactamases. These enzymes were involved in the resistance of strains within the genus to penicillins, cephalosporins, aztreonam, and imipenem but not cefoxitin. Unlike most other organisms with inducible beta-lactamases, all four strains of A. caviae, one of four strains of A. sobria, and one of three strains of A. hydrophila possessed two distinct inducible beta-lactamases. Furthermore, substrate and inhibitor profiles revealed that many of these Aeromonas beta-lactamases were distinct from inducible enzymes that have been characterized in other genera of gram-negative bacteria. Images PMID:3264129

Bakken, J S; Sanders, C C; Clark, R B; Hori, M

1988-01-01

277

Crossover assessment of serum bactericidal activity and pharmacokinetics of five broad-spectrum cephalosporins in the elderly.  

PubMed Central

To better define the pharmacokinetics and serum bactericidal activity (SBA) of the expanded-spectrum cephalosporins in the elderly, we administered single 2-g intravenous infusions of cefoperazone, cefotaxime, ceftriaxone, ceftazidime, and ceftizoxime to six healthy volunteers over the age of 65 years. Serum was collected over 24 h, and concentrations were determined by high-performance liquid chromatography; pharmacokinetic parameters were determined for each drug. SBA was measured against representative strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, and Pseudomonas aeruginosa. All agents tested had excellent SBAs against E. coli and K. pneumoniae, often for a longer duration than would be expected on the basis of conventional dosing regimens. Ceftazidime had the greatest SBA against E. aerogenes and was the only agent with a substantial SBA against P. aeruginosa. Although ceftizoxime had the greatest SBA against S. aureus, none of these cephalosporins had substantial antistaphylococcal SBAs. Pharmacokinetic analysis revealed that cefoperazone and ceftriaxone had markedly different concentration-time profiles in the elderly volunteers than would have been expected on the basis of existing data from younger volunteers. For older patients, dosing guidelines for these two agents may need to be altered. PMID:2393258

Deeter, R G; Weinstein, M P; Swanson, K A; Gross, J S; Bailey, L C

1990-01-01

278

Determination of endotoxin in injectable antibiotic preparations by the chromogenic assay method using a Limulus reagent (Tachypleus hemocyte lysate) and a chromogenic substrate.  

PubMed Central

The effects of 50 antibiotics on the detection and determination of bacterial endotoxins by the chromogenic method using a Limulus reagent (Tachypleus hemocyte lysate) and a chromogenic substrate of p-nitroaniline derivatives were tested, and the antibiotic concentration for 50% inhibition of the chromogenic reaction in the presence of 0.5 ng of endotoxin (Escherichia coli 0111:B4) per ml was estimated. All the antibiotic preparations were depyrogenized by ultrafiltration treatment before they were subjected to the test. The reaction was conducted in the presence of a high concentration (0.5 M) of Tris buffer to constantly maintain the pH of the reaction mixture, and liberated p-nitroaniline was determined by high-pressure liquid chromatography. Several aminoglycosides (amikacin, bekanamycin, kanamycin, and streptomycin sulfate), bleomycin hydrochloride, and fosfomycin disodium showed no inhibition of the reaction up to 20 mg/ml. However, other antibiotics, including penicillins, cephalosporins, macrolides, and tetracyclines, inhibited the reaction concentration dependently. Polymyxin B sulfate was the most potent inhibitor, with less than 8 micrograms/ml for 50% inhibition. It was concluded that the chromogenic method can be applied to the detection and determination of endotoxin in most of the antibiotic preparations. An application of this method to carbenicillin disodium preparations was exemplified. PMID:3700595

Yano, S; Hotta, Y; Takahashi, S

1986-01-01

279

Multiple Antibiotic Resistance Operon Assays.  

National Technical Information Service (NTIS)

An isolated and cloned region of a bacterial chromosome containing a multiple antibiotic resistance operon is disclosed. A description of the structure and function of the operon is provided as are assorted recombinant DNA constructs involving the operon ...

S. B. Levy

2004-01-01

280

The Double Life of Antibiotics  

PubMed Central

Antibiotic resistance is a persistent health care problem worldwide. Evidence for the negative consequences of subtherapeutic feeding in livestock production has been mounting while the antibiotic pipeline is drying up. In recent years, there has been a paradigm shift in our perception of antibiotics. Apart from its roles in self-defense, antibiotics also serve as inter-microbial signaling molecules, regulators of gene expression, microbial food sources, and as mediators of host immune response. “The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily under-dose himself and by exposing his microbes to nonlethal quantities of the drug make them resistant.”~Alexander Fleming PMID:24003650

Yap, Mee-Ngan F.

2013-01-01

281

Antibiotic and Antimicrobial Resistance: Threat Report 2013  

MedlinePLUS

... with Antibiotic-Resistant Bacteria [page 18] Assessment of Domestic Antibiotic-Resistant Threats [page 20] Running Out of Drugs to Treat Serious Gram-Negative Infections [page 22] People at Especially High Risk [page 24] Antibiotic Safety [page 25] Gaps in Knowledge of Antibiotic Resistance [ ...

282

Antibiotics in third molar surgery.  

PubMed

The aim of this survey was to assess the knowledge and practice of Swiss dentists focusing on the use of antibiotics in prophylactic surgical removal of lower wisdom teeth. A postal survey was conducted among all 3288 dentists who are members of the Swiss Dental Society (SSO) representing nearly all dentists in Switzerland. The questionnaire consisted of 13 questions with mostly multiple-choice answers. Demographic profile, surgical experience, the use of antibiotics, and wound management, i.e. wound closure and the use of mouth rinse were assessed. A response rate of 55% was obtained. Most Swiss dentists perform surgical extractions in their practices. Of all dentists, 18.6% used antibiotics routinely, but a large variation was found comparing the three linguistic regions of Switzerland with the highest prescription rate of 48% in the French-speaking south-west of Switzerland. Fifty-two percent of dentists prescribed amoxicillin in a dose of 750 mg. Most often three daily doses were prescribed (47%). A postoperative regime was prescribed by 54.4% of dentists. French language (p=0.003), graduation from the university of Geneva (p=0.007), foreign diplomas (p<0.001), and dentists with diplomas awarded from 2001-2006 (p=0.004) showed a highly significant correlation with the use of antibiotics. In Switzerland, prophylactic antibiotics are used in third molar surgery. Antibiotic prescription however largely depends on geographical situation and dentist profiles. The assessment of antibiotic use in private practices is important in the light of growing evidence that antibiotic overuse may lead to development of multiresistant bacterial strains. In a second part results regarding wound management and mouth rinse will be presented. PMID:24671748

Vlcek, Daniel; Razavi, Amir; Kuttenberger, Johannes J

2014-01-01

283

Static recipient cells as reservoirs of antibiotic resistance during antibiotic therapy  

Microsoft Academic Search

How does taking the full course of antibiotics prevent antibiotic resistant bacteria establishing in patients? We address this question by testing the possibility that horizontal\\/lateral gene transfer (HGT) is critical for the accumulation of the antibiotic-resistance phenotype while bacteria are under antibiotic stress. Most antibiotics prevent bacterial reproduction, some by preventing de novo gene expression. Nevertheless, in some cases and

Allan R. Willms; Paul D. Roughan; Jack A. Heinemann

2006-01-01

284

[Resistance to "last resort" antibiotics in Gram-positive cocci: The post-vancomycin era].  

PubMed

New therapeutic alternatives have been developed in the last years for the treatment of multidrug-resistant Gram-positive infections. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are considered a therapeutic challenge due to failures and lack of reliable antimicrobial options. Despite concerns related to the use of vancomycin in the treatment of severe MRSA infections in specific clinical scenarios, there is a paucity of solid clinical evidence that support the use of alternative agents (when compared to vancomycin). Linezolid, daptomycin and tigecycline are antibiotics approved in the last decade and newer cephalosporins (such as ceftaroline and ceftobiprole) and novel glycopeptides (dalvavancin, telavancin and oritavancin) have reached clinical approval or are in the late stages of clinical development. This review focuses on discussing these newer antibiotics used in the "post-vancomycin" era with emphasis on relevant chemical characteristics, spectrum of antimicrobial activity, mechanisms of action and resistance, as well as their clinical utility. PMID:24968051

Rincón, Sandra; Panesso, Diana; Díaz, Lorena; Carvajal, Lina P; Reyes, Jinnethe; Munita, José M; Arias, César A

2014-04-01

285

In vitro antibiotic susceptibilities of Neisseria gonorrhoeae isolates in the Philippines.  

PubMed

Antibiotic susceptibility surveillance testing was performed on clinical isolates of Neisseria gonorrhoeae collected in September 1989 in the Philippines. beta-Lactamase was produced by 77 (55%) of 140 isolates. In vitro MIC testing revealed significant resistance to penicillin (MIC for 90% of isolates [MIC90], greater than 64 micrograms/ml), tetracycline (MIC90, 4 micrograms/ml), and cefmetazole (MIC90, 8 micrograms/ml). Spectinomycin resistance was rare (10 of 117), but the MIC90 was 32 micrograms/ml. Isolates were susceptible to fluoroquinolones and cephalosporins at the time of this survey, as evidenced by the MIC90s of ciprofloxacin (0.25 microgram/ml), norfloxacin (2.0 micrograms/ml), ofloxacin (0.625 microgram/ml), cefpodoxime (2.0 micrograms/ml), cefotaxime (1.0 microgram/ml), ceftazidime (0.25 microgram/ml), ceftizoxime (0.25 microgram/ml), and ceftriaxone (0.06 microgram/ml). To date, ceftriaxone resistance has not emerged, despite the widespread use of this antibiotic in the Philippines. PMID:1605592

Clendennen, T E; Hames, C S; Kees, E S; Price, F C; Rueppel, W J; Andrada, A B; Espinosa, G E; Kabrerra, G; Wignall, F S

1992-02-01

286

Site-directed mutagenesis of residues 164, 170, 171, 179, 220, 237 and 242 in PER-1 beta-lactamase hydrolysing expanded-spectrum cephalosporins.  

PubMed

The class A beta-lactamase PER-1, which displays 26% identity with the TEM-type extended-spectrum beta-lactamases (ESBLs), is characterized by a substrate profile similar to that conferred by these latter enzymes. The role of residues Ala164, His170, Ala171, Asn179, Arg220, Thr237 and Lys242, found in PER-1, was assessed by site-directed mutagenesis. Replacement of Ala164 by Arg yielded an enzyme with no detectable beta-lactamase activity. Two other mutants, N179D and A164R+N179D, were also inactive. Conversely, a mutant with the A171E substitution displayed a substrate profile very similar to that of the wild-type enzyme. Moreover, the replacement of Ala171 by Glu in the A164R enzyme yielded a double mutant which was active, suggesting that Glu171 could compensate for the deleterious effect of Arg164 in the A164R+A171E enzyme. A specific increase in kcat for cefotaxime was observed with H170N, whereas R220L and T237A displayed a specific decrease in activity towards the same drug and a general increase in affinity towards cephalosporins. Finally, the K242E mutant displayed a kinetic behaviour very similar to that of PER-1. Based on three-dimensional models generated by homology modelling and molecular dynamics, these results suggest novel structure-activity relationships in PER-1, when compared with those previously described for the TEM-type ESBLs. PMID:10325401

Bouthors, A T; Delettré, J; Mugnier, P; Jarlier, V; Sougakoff, W

1999-04-01

287

Incidence of penicillinase producing Neisseria gonorrhoeae (PPNG) strains and susceptibility of gonococcal isolates to antibiotics in Benin City, Nigeria.  

PubMed Central

Of 53 strains of Neisseria gonorrhoeae isolated in Benin City, Nigeria, in February 1983 to October 1984, 46 (87%) produced penicillinase. The minimum inhibitory concentrations (MICs) of penicillin G and ampicillin for these isolates were between 1 mg/l and and 50 mg/l. About 48% (22/46) of the penicillinase producing strains were also resistant to streptomycin, cotrimoxazole, and ampicillin and cloxacillin. All 53 isolates were sensitive to tetracycline, erythromycin, amoxycillin and clavulanic acid, nalidixic acid, spectinomycin, and the penicillinase stable cephalosporins. The high incidence of resistance may have been the result of indiscriminate and unsupervised use of antibiotics before patients presented for proper treatment in clinics and hospitals. PMID:3936776

Obaseiki-Ebor, E E; Oyaide, S M; Okpere, E E

1985-01-01

288

Incidence of penicillinase producing Neisseria gonorrhoeae (PPNG) strains and susceptibility of gonococcal isolates to antibiotics in Benin City, Nigeria.  

PubMed

Of 53 strains of Neisseria gonorrhoeae isolated in Benin City, Nigeria, in February 1983 to October 1984, 46 (87%) produced penicillinase. The minimum inhibitory concentrations (MICs) of penicillin G and ampicillin for these isolates were between 1 mg/l and and 50 mg/l. About 48% (22/46) of the penicillinase producing strains were also resistant to streptomycin, cotrimoxazole, and ampicillin and cloxacillin. All 53 isolates were sensitive to tetracycline, erythromycin, amoxycillin and clavulanic acid, nalidixic acid, spectinomycin, and the penicillinase stable cephalosporins. The high incidence of resistance may have been the result of indiscriminate and unsupervised use of antibiotics before patients presented for proper treatment in clinics and hospitals. PMID:3936776

Obaseiki-Ebor, E E; Oyaide, S M; Okpere, E E

1985-12-01

289

Generations.  

PubMed

Groups naturally promote their strengths and prefer values and rules that give them an identity and an advantage. This shows up as generational tensions across cohorts who share common experiences, including common elders. Dramatic cultural events in America since 1925 can help create an understanding of the differing value structures of the Silents, the Boomers, Gen Xers, and the Millennials. Differences in how these generations see motivation and values, fundamental reality, relations with others, and work are presented, as are some applications of these differences to the dental profession. PMID:16623137

Chambers, David W

2005-01-01

290

Management Options For Reducing The Release Of Antibiotics And Antibiotic Resistance Genes To The Environment  

EPA Science Inventory

Background: There is growing concern worldwide about the role of polluted soil and water - 77 environments in the development and dissemination of antibiotic resistance. 78 Objective: To identify management options for reducing the spread of antibiotics and 79 antibiotic resist...

291

Ferrate(VI) oxidation of ?-lactam antibiotics: reaction kinetics, antibacterial activity changes, and transformation products.  

PubMed

Oxidation of ?-lactam antibiotics by aqueous ferrate(VI) was investigated to determine reaction kinetics, reaction sites, antibacterial activity changes, and transformation products. Apparent second-order rate constants (kapp) were determined in the pH range 6.0-9.5 for the reaction of ferrate(VI) with penicillins (amoxicillin, ampicillin, cloxacillin, and penicillin G), a cephalosporin (cephalexin), and several model compounds. Ferrate(VI) shows an appreciable reactivity toward the selected ?-lactams (kapp for pH 7 = 110-770 M(-1) s(-1)). The pH-dependent kapp could be well explained by considering species-specific reactions between ferrate(VI) and the ?-lactams (with reactions occurring at thioether, amine, and/or phenol groups). On the basis of the kinetic results, the thioether is the main reaction site for cloxacillin and penicillin G. In addition to the thioether, the amine is a reaction site for ampicillin and cephalexin, and amine and phenol are reaction sites for amoxicillin. HPLC/MS analysis showed that the thioether of ?-lactams was transformed to stereoisomeric (R)- and (S)-sulfoxides and then to a sulfone. Quantitative microbiological assay of ferrate(VI)-treated ?-lactam solutions indicated that transformation products resulting from the oxidation of cephalexin exhibited diminished, but non-negligible residual activity (i.e., ?24% as potent as the parent compound). For the other ?-lactams, the transformation products showed much lower (<5%) antibacterial potencies compared to the parent compounds. Overall, ferrate(VI) oxidation appears to be effective as a means of lowering the antibacterial activities of ?-lactams, although alternative approaches may be necessary to achieve complete elimination of cephalosporin activities. PMID:25073066

Karlesa, Anggita; De Vera, Glen Andrew D; Dodd, Michael C; Park, Jihye; Espino, Maria Pythias B; Lee, Yunho

2014-09-01

292

WAAR (World Alliance against Antibiotic Resistance): Safeguarding antibiotics  

PubMed Central

Summary Resistance to antibiotics has increased recently to a dramatic extend, and the pipeline of new antibiotics is almost dry for the five next years. Failures happen already for trivial community acquired infections, like pyelonephritis, or peritonitis, and this is likely to increase. Difficult surgical procedures, transplants, and other immunosuppressive therapies will become far more risky. Resistance is mainly due to an excessive usage of antibiotics, in all sectors, including the animal one. Action is urgently needed. Therefore, an alliance against MDRO has been recently created, which includes health care professionals, consumers, health managers, and politicians. The document highlights the different proposed measures, and represents a strong consensus between the different professionals, including general practicionners, and veterinarians. PMID:22958542

2012-01-01

293

Antibiotic resistance of bacterial biofilms.  

PubMed

A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains. Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute to the survival of biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy and they can be treated by chronic suppressive therapy. A promising strategy may be the use of enzymes that can dissolve the biofilm matrix (e.g. DNase and alginate lyase) as well as quorum-sensing inhibitors that increase biofilm susceptibility to antibiotics. PMID:20149602

Høiby, Niels; Bjarnsholt, Thomas; Givskov, Michael; Molin, Søren; Ciofu, Oana

2010-04-01

294

In vitro activities of E1101, a novel oral cephalosporin, against bacteria causing infections in obstetric and gynecological patients.  

PubMed

E1101 is a new oral cephalosporin with a broad spectrum of antibacterial activity. It inhibited more than 90% of clinical isolates of Streptococcus agalactiae, Escherichia coli and Peptostreptococcus magnus at the concentration of 3.13 mg/l. E1101 was the most active agent against S. agalactiae and E. coli. Since none of the compounds was sufficiently active against the Bacteroides fragilis and Prevotella bivia isolates, they are not appropriate in the treatment of patients with infections caused by these organisms. The results of this study suggest that, subject to confirmation by clinical trials, E1101, in combination with an agent with reliable activity against anaerobic bacteria, is suitable as empirical therapy of patients with obstetric and gynecological infections. PMID:9732148

Mikamo, H; Sato, Y; Hayasaki, Y; Kawazoe, K; Tamaya, T

1998-01-01

295

Forces shaping the antibiotic resistome.  

PubMed

Antibiotic resistance has become a problem of global scale. Resistance arises through mutation or through the acquisition of resistance gene(s) from other bacteria in a process called horizontal gene transfer (HGT). While HGT is recognized as an important factor in the dissemination of resistance genes in clinical pathogens, its role in the environment has been called into question by a recent study published in Nature. The authors found little evidence of HGT in soil using a culture-independent functional metagenomics approach, which is in contrast to previous work from the same lab showing HGT between the environment and human microbiome. While surprising at face value, these results may be explained by the lack of selective pressure in the environment studied. Importantly, this work suggests the need for careful monitoring of environmental antibiotic pollution and stringent antibiotic stewardship in the fight against resistance. PMID:25213620

Perry, Julie A; Wright, Gerard D

2014-12-01

296

[Antibiotic treatment in Lyme arthritis].  

PubMed

Primary cause of Lyme arthritis (LA) is an invasion and survival of Borrelia burgdorferi s.l. spirochetes within joint tissues. Elimination of the pathogen is an effective treatment method in a great majority of patients and can be achieved by a number of antibiotic regimens of confirmed efficacy. Antibiotic therapy lasting for 2 to 4 weeks enables eradication of the infection, followed by resolution of arthritis within weeks to months. If insufficient, the course of therapy may be repeated up to 3 times in a few months' intervals, although effectiveness of repeated treatment is not so well confirmed and probably small. Further symptoms, persisting in spite of proper antibiotherapy, typically are not caused by ongoing infection, but rather by autoimmune phenomena or persistent damage to the joint, so further administration of antibiotics in such patients seems of no benefit. PMID:22320035

Grygorczuk, Sambor; Zajkowska, Joanna; Kondrusik, Maciej; Moniuszko, Anna; Pancewicz, S?awomir

2008-01-01

297

The need for a veterinary antibiotic policy.  

PubMed

The international recognition of the 'stable to table' approach to food safety emphasises the need for appropriate and safe use of antibiotics in animal production. An appropriate use of antibiotics for food animals will preserve the long-term efficacy of existing antibiotics, support animal health and welfare and limit the risk of transfer of antibiotic resistance to humans. Furthermore, it may promote consumer confidence in the veterinary use of antibiotics. In advancing these arguments, the authors of this article argue that there is a need for a visible and operational policy for veterinary use of antibiotics, paying particular attention to the policies that are being developed in Denmark. PMID:10458580

Pedersen, K B; Aarestrup, F M; Jensen, N E; Bager, F; Jensen, L B; Jorsal, S E; Nielsen, T K; Hansen, H C; Meyling, A; Wegener, H C

1999-07-10

298

Effect of UV-B radiation on some common antibiotics  

Microsoft Academic Search

Some of the commonly used antibiotics such as cephaloridine, cephalexin, cephradine, nystatin and nafcillin were tested for generation of singlet oxygen (1O2) under UV-B (290–320 nm) exposure and the order for 1O2 generation was obtained: cephaloridine>cephalexin>nystatin>cephradine>nafcillin. In vitro study with deoxyguanosine (dGuo) showed that 1O2 was responsible for drug-sensitized photodegradation of the guanine base of DNA and RNA. Sodium azide

R. S Ray; R. B Misra; M Farooq; R. K Hans

2002-01-01

299

MICROBIOLOGY: Noninherited Resistance to Antibiotics  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Why is it that the rate of mortality of bacteria exposed to bactericidal antibiotics declines with time but sensitive cells survive for hours or even days of exposure? The mechanisms responsible for this persistence have perplexed microbiologists for decades. In his Perspective, Levin discusses a pair of recent studies (Balaban et al., Miller et al.) that shed light on the mechanisms responsible for this phenomenon and the way in which these bacterial persisters emerge. Levin also considers the potential clinical implications of this non-inherited form of resistance to antibiotics.

Bruce R. Levin (Emory University;Department of Biology)

2004-09-10

300

How ?-Lactam Antibiotics Enter Bacteria: A Dialogue with the Porins  

PubMed Central

Background Multi-drug resistant (MDR) infections have become a major concern in hospitals worldwide. This study investigates membrane translocation, which is the first step required for drug action on internal bacterial targets. ?-lactams, a major antibiotic class, use porins to pass through the outer membrane barrier of Gram-negative bacteria. Clinical reports have linked the MDR phenotype to altered membrane permeability including porin modification and efflux pump expression. Methodology/Principal Findings Here influx of ?-lactams through the major Enterobacter aerogenes porin Omp36 is characterized. Conductance measurements through a single Omp36 trimer reconstituted into a planar lipid bilayer allowed us to count the passage of single ?-lactam molecules. Statistical analysis of each transport event yielded the kinetic parameters of antibiotic travel through Omp36 and distinguishable translocation properties of ?-lactams were quantified for ertapenem and cefepime. Expression of Omp36 in an otherwise porin-null bacterial strain is shown to confer increases in the killing rate of these antibiotics and in the corresponding bacterial susceptibility. Conclusions/Significance We propose the idea of a molecular “passport” that allows rapid transport of substrates through porins. Deciphering antibiotic translocation provides new insights for the design of novel drugs that may be highly effective at passing through the porin constriction zone. Such data may hold the key for the next generation of antibiotics capable of rapid intracellular accumulation to circumvent the further development MDR infections. PMID:19434239

Molitor, Alexander; Bolla, Jean-Michel; Bessonov, Andrey N.; Winterhalter, Mathias; Pages, Jean-Marie

2009-01-01

301

Biological activities of two fungistatic antibiotics produced by Bacillus cereus UW85.  

PubMed Central

Cultures and culture filtrates of Bacillus cereus UW85 suppress damping-off of alfalfa caused by Phytophthora medicaginis. We studied the role in disease suppression of two antibiotics from culture filtrates of UW85 that reversibly inhibited growth of P. medicaginis. We purified the two antibiotics by cation-exchange chromatography and high-voltage paper electrophoresis and showed that one of them, designated zwittermicin A, was an aminopolyol of 396 Da that was cationic at pH 7.0; the second, designated antibiotic B, appeared to be an aminoglycoside containing a disaccharide. Both antibiotics prevented disease of alfalfa seedlings caused by P. medicaginis. Purified zwittermicin A reversibly reduced elongation of germ tubes derived from cysts of P. medicaginis, and antibiotic B caused swelling of the germ tubes. Mutants generated with Tn917 or mitomycin C treatment were screened either for antibiotic accumulation in an agar plate diffusion assay or for the ability to suppress damping-off disease of alfalfa. Of 2,682 mutants screened for antibiotic accumulation, 5 mutants were substantially reduced in antibiotic accumulation and disease-suppressive activity. Of the 1,700 mutants screened for disease-suppressive activity, 3 mutants had reduced activity and they accumulated less of both antibiotics than did the parent strain. The amount of antibiotic accumulated by the mutants was significantly correlated with the level of disease suppression. Addition of either zwittermicin A or antibiotic B to alfalfa plants inoculated with a culture of a nonsuppressive mutant resulted in disease suppression. These results demonstrate that B. cereus UW85 produces two fungistatic antibiotics that contribute to suppression of damping-off disease of alfalfa. Images PMID:8031096

Silo-Suh, L A; Lethbridge, B J; Raffel, S J; He, H; Clardy, J; Handelsman, J

1994-01-01

302

When and How to Take Antibiotics  

MedlinePLUS

... unnecessarily you may contribute to the development of antibiotic resistance. If you become sick and your bacteria are resistant to your prescribed antibiotic, your illness lasts longer and you may have ...

303

Alliance for the Prudent Use of Antibiotics  

MedlinePLUS

... the Center for Adaptation Genetics and Drug Resistance . Antibiotic Resistance in the News Tweets by @APUANews 2014 ... 2013 CDC Report: Vol. 32 No. 2: Tracking Antibiotic Resistance Genes in the Environment Vol. 32 No. ...

304

Impacts of Antibiotic-Resistant Bacteria.  

National Technical Information Service (NTIS)

Partial Contents: Summary, Conclusions, Issues and Options; Introduction; Antibiotic Use and Resistance in the Community (Populations Susceptible to Antibiotic-Resistant Bacteria, Factors in the Emergence of Bacterial Diseases, Changes in Disease Patterns...

1995-01-01

305

Antibiotic Might Raise Heart Risks for Some  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Antibiotic Might Raise Heart Risks for Some People with ... Preidt Wednesday, August 20, 2014 Related MedlinePlus Pages Antibiotics Arrhythmia TUESDAY, Aug. 19, 2014 (HealthDay News) -- Taking ...

306

Fundamentals of the Study of Antibiotics.  

National Technical Information Service (NTIS)

Contents: Antagonism in the world of microorganisms, searches for producers and antibiotic substances in nature, conditions of the formation of antibiotics and their biological role: Interrelationships of microorganisms under natural conditions; The conce...

N. S. Egorov

1967-01-01

307

Aminoglycoside Antibiotics and Methods of Using Same.  

National Technical Information Service (NTIS)

The present invention relates to aminoglycoside compounds having antibiotic activity. Moreover, the present invention relates to L-aminoglycoside compounds and diastereomers thereof which posses antibiotic activity and are not susceptible to development o...

R. R. Rando

2004-01-01

308

Evaluation of an Automated Antibiotic Consultant.  

National Technical Information Service (NTIS)

In the treatment of infection, physicians frequently need to begin antibiotic therapy before the results of bacterial and susceptibility tests are available. The empiric use of antibiotics is based on clinical experience and a knowledge of the most freque...

R. S. Evans, D. C. Classen, S. L. Pestotnik, H. P. Lundsgaarde, J. P. Burke

1994-01-01

309

Antibiotic Activity in Space, Results and Hypothesis.  

National Technical Information Service (NTIS)

Modifications of structure and function of bacteria, particularly in response to antibiotics, induced by spacecraft environments were examined on Spacelab and Salyut. The increase of antibiotic resistance may be due to a stimulating effect on the cell mul...

L. Lapchine, N. Moatti, G. Richoilley, J. Templier, G. Gasset

1987-01-01

310

Origins and Evolution of Antibiotic Resistance  

PubMed Central

Summary: Antibiotics have always been considered one of the wonder discoveries of the 20th century. This is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. The extraordinary genetic capacities of microbes have benefitted from man's overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiotic introduced into practice clinically, agriculturally, or otherwise. This review presents the salient aspects of antibiotic resistance development over the past half-century, with the oft-restated conclusion that it is time to act. To achieve complete restitution of therapeutic applications of antibiotics, there is a need for more information on the role of environmental microbiomes in the rise of antibiotic resistance. In particular, creative approaches to the discovery of novel antibiotics and their expedited and controlled introduction to therapy are obligatory. PMID:20805405

Davies, Julian; Davies, Dorothy

2010-01-01

311

Antibiotic use and risk of gynecological cancer  

Microsoft Academic Search

ObjectivesSeveral studies addressed the association between antibiotic use and breast cancer risk. The objective of this study was to assess the association between antibiotic use and risk of cervical, ovarian, and uterine cancer.

Hani M. Tamim; Khaled M. Musallam; Hanan M. F. Al Kadri; Jean-François Boivin; Jean-Paul Collet

312

Antibiotic resistance: location, location, location  

Microsoft Academic Search

Antibiotic resistance surveys are published widely, citing percentage resistance rates, sometimes for vast transcontinental regions. Such data seem straightforward, but when one drills deeper, great complexity emerges. Rates for methicillin resistance among Staphylococcus aureus from bacteraemias vary from <1% to 50% among European countries, and vary greatly among both hospitals and hospital units. Methicillin-resistant S. aureus (MRSA) resistance rates are

D. M. Livermore; A. Pearson

2007-01-01

313

Are Preoperative Antibiotics Administered Preoperatively?  

Microsoft Academic Search

Ideally antibiotics should be administered preopera tively within 2 hours of skin incision, to ensure adequate tissue concentrations, especially when a vascular pros thesis is used. The quality of patient outcomes may be ad versely affected when key processes, by degrees, fail to meet patient care objectives. This study was designed to incorporate the concepts of total quality management to

Paul E. Collier; Marilyn Rudolph; Debra Ruckert; Thomas Osella; Nancy A. Collier; Marcia Ferrero

1998-01-01

314

New Antibiotic Approved by FDA  

NSDL National Science Digital Library

Last week, the FDA approved Zyvox (known generically as linezolid), the first in a new class of synthetic antibacterial drugs -- called oxazolidinones -- designed to treat a number of drug-resistant infections. Zyvox has proven effective in treatment of infections associated with vancomycin-resistant Enterococcus faecium (VREF) as well as hospital-acquired pneumonia and complicated skin and skin structure infections, including cases caused by methicillin-resistant Staphylococcus aureus (MRSA). This is the first drug to be approved in over 40 years for fighting hospital-acquired infections that are resistant to antibiotics. "It comes at a time when we were literally running out of antibiotics," said Dr. Robert C. Moellering Jr., physician-in-chief of Boston's Beth Israel-Deaconness Hospital, in a recent AP news article. In an attempt to preserve the long-term effectiveness of Zyvox and discourage microbes from developing renewed resistance, some doctors are calling for cautious use of the drug for only the worst antibiotic-resistant infections. This week's In The News takes a look at this new development and its consequences for antibiotic resistant bacteria.

Ramanujan, Krishna.

315

Antibiotic Resistance: Consequences of Inaction  

Microsoft Academic Search

Bacterial resistance presents therapeutic dilemmas to clinicians worldwide. The warnings were there long ago, but too few people heeded them. Thus an emerging problem has grown to a crisis. Resistance is an ecological phenomenon stemming from the response of bacteria to the widespread use of antibiotics and their presence in the environment. While determining the consequences of inaction on the

2001-01-01

316

A Mutation of the RNA Polymerase ?? Subunit (rpoC) Confers Cephalosporin Resistance in Bacillus subtilis  

PubMed Central

In bacteria, mutations affecting the major catalytic subunits of RNA polymerase (encoded by rpoB and rpoC) emerge in response to a variety of selective pressures. Here we isolated a Bacillus subtilis strain with high-level resistance to cefuroxime (CEF). Whole-genome resequencing revealed only one missense mutation affecting an invariant residue in close proximity to the C-terminal DNA-binding domain of RpoC (G1122D). Genetic reconstruction experiments demonstrate that this substitution is sufficient to confer CEF resistance. The G1122D mutation leads to elevated expression of stress-responsive regulons, including those of extracytoplasmic function (ECF) ? factors (?M, ?W, and ?X) and the general stress ? factor (?B). The increased CEF resistance of the rpoCG1122D strain is lost in the sigM rpoCG1122D double mutant, consistent with a major role for ?M in CEF resistance. However, a sigM mutant is very sensitive to CEF, and this sensitivity is still reduced by the G1122D mutation, suggesting that other regulatory effects are also important. Indeed, the ability of the G1122D mutation to increase CEF resistance is further reduced in a triple mutant strain lacking three ECF ? factors (?M, ?W, and ?X), which are known from prior studies to control overlapping sets of genes. Collectively, our findings highlight the ability of mutations in RNA polymerase to confer antibiotic resistance by affecting the activity of alternative ? factors that control cell envelope stress-responsive regulons. PMID:23070162

Lee, Yong Heon; Nam, Ki Hyun

2013-01-01

317

Laehnemann et al. Genomics of rapid adaptation to antibiotics  

E-print Network

antibiotic resistance evolution. Results: Our new analyses demonstrate that amplification of a sequence mechanism to high antibiotic stress. Keywords: antibiotic resistance; convergent evolution; Escherichia coli- ulations restore growth to almost untreated levels [5]. Such fast antibiotic resistance evolution

Beardmore, Robert

318

Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria  

Microsoft Academic Search

MICROBIAL RESISTANCE TO ANTIBIOTICS IS ON THE RISE, in part because of inappropriate use of antibiotics in human medicine but also because of practices in the agricul- tural industry. Intensive animal production involves giving livestock animals large quantities of antibiotics to promote growth and prevent infection. These uses pro- mote the selection of antibiotic resistance in bacterial populations. The resistant

George G. Khachatourians

1998-01-01

319

Are Sewage Treatment Plants Promoting Antibiotic Resistance?  

Microsoft Academic Search

There is widespread speculation that sewage treatment plants (STPs) and aquatic environments in general may be breeding grounds for antibiotic resistant bacteria. We examine the question of whether low concentrations of antibiotics in STPs can provide or contribute to a selective pressure facilitating the acquisition or proliferation of antibiotic resistance among bacteria in the receiving environment. Examination of available literature

Karen L. Jury; Stuart J. Khan; Tony Vancov; Richard M. Stuetz; Nicholas J. Ashbolt

2011-01-01

320

Predicting the evolution of antibiotic resistance genes  

Microsoft Academic Search

Antibiotic resistance is thought to evolve rapidly in response to antibiotic use. At present, we lack effective tools to assess how rapidly existing resistance genes are likely to evolve to yield resistance to newly introduced drugs. To address this problem, a method has been developed for in vitro evolution experiments to help predict how long it will take antibiotic resistance

Barry G. Hall

2004-01-01

321

New business models for antibiotic innovation  

PubMed Central

The increase in antibiotic resistance and the dearth of novel antibiotics have become a growing concern among policy-makers. A combination of financial, scientific, and regulatory challenges poses barriers to antibiotic innovation. However, each of these three challenges provides an opportunity to develop pathways for new business models to bring novel antibiotics to market. Pull-incentives that pay for the outputs of research and development (R&D) and push-incentives that pay for the inputs of R&D can be used to increase innovation for antibiotics. Financial incentives might be structured to promote delinkage of a company’s return on investment from revenues of antibiotics. This delinkage strategy might not only increase innovation, but also reinforce rational use of antibiotics. Regulatory approval, however, should not and need not compromise safety and efficacy standards to bring antibiotics with novel mechanisms of action to market. Instead regulatory agencies could encourage development of companion diagnostics, test antibiotic combinations in parallel, and pool and make transparent clinical trial data to lower R&D costs. A tax on non-human use of antibiotics might also create a disincentive for non-therapeutic use of these drugs. Finally, the new business model for antibiotic innovation should apply the 3Rs strategy for encouraging collaborative approaches to R&D in innovating novel antibiotics: sharing resources, risks, and rewards. PMID:24646116

Shah, Tejen A.

2014-01-01

322

Microbiology Lab 7 Determination of Antibiotic Sensitivity  

E-print Network

Microbiology Lab 7 Determination of Antibiotic Sensitivity Disk diffusion/ Kirby-Bauer Method Thus as antibiotics, act to inhibit bacterial growth in a variety of ways. See below. 1) disruption of a metabolic vary in a number ways, (i.e. types of metabolism used , cell wall structure) specific antibiotics vary

323

Antibiotic treatment for acute otitis media  

Microsoft Academic Search

The major problems encountered in the antibiotic therapy of acute otitis media (AOM) are the tremendous increase in the resistance to antibiotics of its main pathogens and the lack of tight criteria (taking into consideration, as a major determinant, the eradication of the pathogens from the middle ear fluid) in the selection of the appropriate antibiotic drugs for the treatment

Eugene Leibovitz; Ron Dagan

2000-01-01

324

Genetic Architecture of Intrinsic Antibiotic Susceptibility  

Microsoft Academic Search

Background: Antibiotic exposure rapidly selects for more resistant bacterial strains, and both a drug's chemical structure and a bacterium's cellular network affect the types of mutations acquired. Methodology\\/Principal Findings: To better characterize the genetic determinants of antibiotic susceptibility, we exposed a transposon-mutagenized library of Escherichia coli to each of 17 antibiotics that encompass a wide range of drug classes and

Hany S. Girgis; Alison K. Hottes; Saeed Tavazoie

2009-01-01

325

Perioperative Antibiotic Process Improvement Reaps Rewards  

Microsoft Academic Search

Recent health care improvement initiatives have linked financial payments to compliance with predetermined performance measures. This article reports the effect of a unique prophylactic antibiotic use program on compliance rates and costs. The Departments of Surgery, Infection Control, and Anesthesiology collaborated on a prophylactic preoperative antibiotic protocol, whereby Anesthesiology assumed responsibility for timely antibiotic prophylaxis (TAP) before surgical incision. Data

Brenda G. Fahy; Edwin A. Bowe; Joseph Conigliaro

2011-01-01

326

Perioperative antibiotic prophylaxis and prosthetic valve endocarditis  

Microsoft Academic Search

A study of twenty-five cases of prosthetic valve endocarditis suggests that the antibiotics used for perioperative prophylaxis may alter the type and antibiotic sensitivity of organisms which subsequently infect the artificial valves. Based on the results of this study, the authors have been able to modify their prophylactic regime to encompass these organisms and to predict the antibiotics most likely

C. Ward; A. E. Jephcott; C. A. Hardisty

1977-01-01

327

A call for antibiotic alternatives research.  

PubMed

The persistence and spread of antibiotic resistance, in conjunction with decreased profitability of new antibiotics, have created the dangerous prospect of ineffective therapies against bacterial diseases. National strategies aimed at discovery, development, and definition of the mechanisms of effective antibiotic alternatives, especially for agricultural applications, should be encouraged. PMID:23473628

Stanton, Thaddeus B

2013-03-01

328

New business models for antibiotic innovation.  

PubMed

The increase in antibiotic resistance and the dearth of novel antibiotics have become a growing concern among policy-makers. A combination of financial, scientific, and regulatory challenges poses barriers to antibiotic innovation. However, each of these three challenges provides an opportunity to develop pathways for new business models to bring novel antibiotics to market. Pull-incentives that pay for the outputs of research and development (R&D) and push-incentives that pay for the inputs of R&D can be used to increase innovation for antibiotics. Financial incentives might be structured to promote delinkage of a company's return on investment from revenues of antibiotics. This delinkage strategy might not only increase innovation, but also reinforce rational use of antibiotics. Regulatory approval, however, should not and need not compromise safety and efficacy standards to bring antibiotics with novel mechanisms of action to market. Instead regulatory agencies could encourage development of companion diagnostics, test antibiotic combinations in parallel, and pool and make transparent clinical trial data to lower R&D costs. A tax on non-human use of antibiotics might also create a disincentive for non-therapeutic use of these drugs. Finally, the new business model for antibiotic innovation should apply the 3Rs strategy for encouraging collaborative approaches to R&D in innovating novel antibiotics: sharing resources, risks, and rewards. PMID:24646116

So, Anthony D; Shah, Tejen A

2014-05-01

329

Antibiotics in Milk—A Review1  

Microsoft Academic Search

SUIVi I~IARY The widespread use of antibiotics has contributed to the control of diseases and the nutritional well-being of livestock. However, the use of antibiotics in the treatment of mastitis has created problems for the milk processor and consumer. Following treatment of mastitis with antibiotics, they may be found in the milk in sufficient concentrations to inhibit dairy starter microorganisms

J. L. Albright; S. L. Tuckey; G. T. Woods

1961-01-01

330

Treatment and prevention of antibiotic associated diarrhea  

Microsoft Academic Search

Mild or severe episodes of antibiotic-associated diarrhea (AAD) are common side effects of antibiotic therapy. The incidence of AAD differs with the antibiotic and varies from 5 to 25%. The major form of intestinal disorders is the pseudomembranous colitis associated with Clostridium difficile which occurs in 10–20% of all AAD. In most cases of AAD discontinuation or replacement of the

E Bergogne-Bérézin

2000-01-01

331

European Antibiotic Awareness Day 2011: antibiotics--a powerful tool and a dwindling resource.  

PubMed

The increasing resistance of microorganisms to a range of antibiotics is of growing concern to healthcare professionals world wide. A correlation between antibiotic resistance and high prescribing rates has long been established. However, despite numerous awareness campaigns, antibiotic prescribing rates are still high and increasing in many countries including the UK. The European Antibiotic Awareness Day on 18 November 2011 provides a platform to remind prescribers and the general public about the dangers of antibiotic overuse. The key message is to encourage prudent antibiotic prescribing so that antibiotics remain a safe and effective resource for the future. PMID:21926061

Zenner, Dominik; Shetty, Nandini

2011-10-01

332

Antibiotic sensitivity pattern of uropathogens from pregnant women with urinary tract infection in Abakaliki, Nigeria  

PubMed Central

Background Urinary tract infection (UTI) is a common bacterial infection during pregnancy and a significant cause of perinatal and maternal morbidity and mortality. The causative bacteria have remained virtually the same although with variations in individual prevalence. There has been an increasing resistance by these bacteria to the commonly available antibiotics. Objectives To determine the prevalence of UTI, the common causative bacteria, and their antibiotic sensitivity pattern among pregnant women with UTI. Methodology This is a descriptive study that was carried out at the Obstetrics Department of two tertiary institutions in Abakaliki, Ebonyi State, Nigeria (Federal Medical Center and Ebonyi State University Teaching Hospital) over a period of 12 months. Midstream urine specimens from selected pregnant women with clinical features of UTI were collected for microscopy, culture, and sensitivity. The results were analyzed with the 2008 Epi Info™ software. Results A total of 542 pregnant women presented with symptoms of UTI and were recruited for the study over the study period. Of the 542 pregnant women, 252 (46.5%) had significant bacteriuria with positive urine culture and varying antibiotic sensitivity pattern. The prevalence of symptomatic UTI was 3%. Escherichia coli was the most common bacteria isolated with a percentage of 50.8%. Other isolated micro organisms included Stapylococcus aereus (52 cultures, 20.6%), Proteus mirabilis (24 cultures, 9.5%), S. saprophyticus (18 cultures, 7.1%), Streptococcus spp. (14 cultures, 5.6%), Citrobacter spp. (5 cultures, 2.0%), Klebsiella spp. (4 cultures, 1.6%), Enterobacter spp. (4 cultures, 1.6%), and Pseudomonas spp. (3 cultures, 1.2%). Levofloxacin had the highest overall antibiotic sensitivity of 92.5%. Others with overall antibiotic sensitivity pattern greater than 50% included cefpodoxime (87.3%), ofloxacin (77.4%), ciprofloxacin (66.7%), ceftriaxone (66.7%), and gentamicin (50.8%). Conclusion E. coli was the most common etiological agent of UTI in pregnancy with Enterococcus (Staphylococcus) gaining prominence. Cephalosporin and quinolones were shown to be very effective against the organisms causing UTI in these pregnant women. PMID:24324344

Onoh, RC; Umeora, OUJ; Egwuatu, VE; Ezeonu, PO; Onoh, TJP

2013-01-01

333

Evidence-based adjustment of antibiotic in pediatric complicated appendicitis in the era of antibiotic resistance  

Microsoft Academic Search

Introduction  Antibiotic resistance is a global issue especially in developed areas. With the emergence of antibiotic resistant-bacteria,\\u000a the traditional choice of broad spectrum antibiotics may not be effective in complicated appendicitis. We herein report the\\u000a bacteriology and antibiotic susceptibility of intra-operative peritoneal culture in children with acute appendicitis in Hong\\u000a Kong. This may guide us to adjust the choice of antibiotics

Kin Wai Edwin Chan; Kim Hung Lee; Jennifer Wai Cheung Mou; Sing Tak Cheung; Jennifer Dart Yin Sihoe; Yuk Him Tam

2010-01-01

334

Methicillin-resistant Staphylococcus aureus-induced thrombo-inflammatory response is reduced with timely antibiotic administration  

PubMed Central

Summary Methicillin-resistant Staphylococcus aureus (MRSA) induces a pro-thrombotic and pro-inflammatory milieu. Although timely antibiotic administration in MRSA sepsis may improve outcomes by arresting bacterial growth, the effects of antibiotics on mitigating injurious thrombo-inflammatory cellular responses remains unexplored. Using a newly developed human whole blood model and an in vivo mouse model of MRSA infection, we examined how antibiotics inhibit MRSA induced thrombo-inflammatory pathways. Human whole blood was inoculated with MRSA. Thrombin generation and inflammatory cytokine synthesis was measured in the presence or absence of linezolid and vancomycin. C57BL/6 mice were injected with MRSA and the effect of vancomycin administration was examined. MRSA accelerated thrombin generation in a time- and concentration-dependent manner and induced the release of cytokines, including interleukin (IL)-6, IL-8, and monocyte chemotactic protein (MCP)-1. The increase in thrombin generation and inflammatory responses was mediated through the synthesis of tissue factor and cytokines, respectively, and the release of microparticles. The early administration of antibiotics restored normal thrombin generation patterns and significantly reduced the synthesis of cytokines. In contrast, when antibiotic administration was delayed, thrombin generation and cytokine synthesis were not significantly reduced. In mice infected with MRSA, early antibiotic administration reduced thrombin anti-thrombin complexes and cytokine synthesis, whereas delayed antibiotic administration did not. These data provide novel mechanistic evidence of the importance of prompt antibiotic administration in infectious syndromes. PMID:23348831

Franks, Zechariah; Campbell, Robert A.; de Abreu, Adriana Vieira; Holloway, Jeffrey T.; Marvin, James E.; Kraemer, Bjoern F.; Zimmerman, Guy A.; Weyrich, Andrew S.; Rondina, Matthew T.

2013-01-01

335

Antibiotics induce redox-related physiological alterations as part of their lethality.  

PubMed

Deeper understanding of antibiotic-induced physiological responses is critical to identifying means for enhancing our current antibiotic arsenal. Bactericidal antibiotics with diverse targets have been hypothesized to kill bacteria, in part by inducing production of damaging reactive species. This notion has been supported by many groups but has been challenged recently. Here we robustly test the hypothesis using biochemical, enzymatic, and biophysical assays along with genetic and phenotypic experiments. We first used a novel intracellular H2O2 sensor, together with a chemically diverse panel of fluorescent dyes sensitive to an array of reactive species to demonstrate that antibiotics broadly induce redox stress. Subsequent gene-expression analyses reveal that complex antibiotic-induced oxidative stress responses are distinct from canonical responses generated by supraphysiological levels of H2O2. We next developed a method to quantify cellular respiration dynamically and found that bactericidal antibiotics elevate oxygen consumption, indicating significant alterations to bacterial redox physiology. We further show that overexpression of catalase or DNA mismatch repair enzyme, MutS, and antioxidant pretreatment limit antibiotic lethality, indicating that reactive oxygen species causatively contribute to antibiotic killing. Critically, the killing efficacy of antibiotics was diminished under strict anaerobic conditions but could be enhanced by exposure to molecular oxygen or by the addition of alternative electron acceptors, indicating that environmental factors play a role in killing cells physiologically primed for death. This work provides direct evidence that, downstream of their target-specific interactions, bactericidal antibiotics induce complex redox alterations that contribute to cellular damage and death, thus supporting an evolving, expanded model of antibiotic lethality. PMID:24803433

Dwyer, Daniel J; Belenky, Peter A; Yang, Jason H; MacDonald, I Cody; Martell, Jeffrey D; Takahashi, Noriko; Chan, Clement T Y; Lobritz, Michael A; Braff, Dana; Schwarz, Eric G; Ye, Jonathan D; Pati, Mekhala; Vercruysse, Maarten; Ralifo, Paul S; Allison, Kyle R; Khalil, Ahmad S; Ting, Alice Y; Walker, Graham C; Collins, James J

2014-05-20

336

Antibiotic effectiveness: balancing conservation against innovation.  

PubMed

Antibiotic effectiveness is a natural societal resource that is diminished by antibiotic use. As with other such assets, keeping it available requires both conservation and innovation. Conservation encompasses making the best use of current antibiotic effectiveness by reducing demand through vaccination, infection control, diagnostics, public education, incentives for clinicians to prescribe fewer antibiotics, and restrictions on access to newer, last-resort antibiotics. Innovation includes improving the efficacy of current drugs and replenishing effectiveness by developing new drugs. In this paper, I assess the relative benefits and costs of these two approaches to maintaining our ability to treat infections. PMID:25214620

Laxminarayan, Ramanan

2014-09-12

337

Infection, antibiotics, and preterm delivery.  

PubMed

The relationship between genital tract infection and preterm delivery has been established on the basis of biochemical, microbiological, and clinical evidence. In theory, pathogenic bacteria may ascend from the lower reproductive tract into the uterus, and the resulting inflammation leads to preterm labor, rupture of the membranes, and birth. A growing body of evidence suggests that preterm labor and/rupture of the membranes are triggered by micro-organisms in the genital tract and by the host response to these organisms, ie, elaboration of cytokines and proteolytic enzymes. Epidemiologic and in vitro studies do not prove a cause-and-effect relationship between infection and preterm birth. However, the preponderance of evidence indicates that treatment of asymptomatic bacteriuria and symptomatic lower genital tract infections such as bacterial vaginosis (BV), trichomoniasis, gonorrhea, and chlamydia will lower the risk of preterm delivery. Based on current evidence, pregnant women who note an abnormal vaginal discharge should be tested for BV, trichomonas, gonorrhea, and chlamydia. Those who test positive should be treated appropriately. A 3- to 7-day course of antibiotic treatment for asymptomatic bacteriuria during pregnancy is clinically indicated to reduce the risk of pyelonephritis and preterm delivery. Routine screening for chlamydia and gonorrhea should be performed for women at high risk of acquiring sexually transmitted diseases. The practice of routine screening for BV in asymptomatic women who are at low risk for preterm delivery cannot be supported based on evidence from the literature. Routine screening for asymptomatic bacteriuria during pregnancy is cost-effective, particularly in high-prevalence populations. The results of antibiotic trials for the treatment of preterm labor have been inconsistent. In the absence of reasonable evidence that antimicrobial therapy leads to significant prolongation of pregnancy in the setting of preterm labor, antibiotics should be used only for protecting the neonate from group B streptococci sepsis. They should not be used for the purpose of prolonging pregnancy. Multiple investigations have shown that, in patients with preterm premature rupture of the membranes, prophylactic antibiotics are of value in prolonging the latent period between rupture of the membranes and onset of labor and in reducing the incidence of maternal and neonatal infection. The most extensively tested effective antibiotic regimen for prophylaxis involves erythromycin alone or in combination with ampicilln. Controversy still exists regarding the appropriate length and route of antibiotic prophylaxis. PMID:11707017

Locksmith, G; Duff, P

2001-10-01

338

Community-Onset Escherichia coli Infection Resistant to Expanded-Spectrum Cephalosporins in Low-Prevalence Countries  

PubMed Central

By global standards, the prevalence of community-onset expanded-spectrum-cephalosporin-resistant (ESC-R) Escherichia coli remains low in Australia and New Zealand. Of concern, our countries are in a unique position, with high extramural resistance pressure from close population and trade links to Asia-Pacific neighbors with high ESC-R E. coli rates. We aimed to characterize the risks and dynamics of community-onset ESC-R E. coli infection in our low-prevalence region. A case-control methodology was used. Patients with ESC-R E. coli or ESC-susceptible E. coli isolated from blood or urine were recruited at six geographically dispersed tertiary care hospitals in Australia and New Zealand. Epidemiological data were prospectively collected, and bacteria were retained for analysis. In total, 182 patients (91 cases and 91 controls) were recruited. Multivariate logistic regression identified risk factors for ESC-R among E. coli strains, including birth on the Indian subcontinent (odds ratio [OR] = 11.13, 95% confidence interval [95% CI] = 2.17 to 56.98, P = 0.003), urinary tract infection in the past year (per-infection OR = 1.430, 95% CI = 1.13 to 1.82, P = 0.003), travel to southeast Asia, China, the Indian subcontinent, Africa, and the Middle East (OR = 3.089, 95% CI = 1.29 to 7.38, P = 0.011), prior exposure to trimethoprim with or without sulfamethoxazole and with or without an expanded-spectrum cephalosporin (OR = 3.665, 95% CI = 1.30 to 10.35, P = 0.014), and health care exposure in the previous 6 months (OR = 3.16, 95% CI = 1.54 to 6.46, P = 0.02). Among our ESC-R E. coli strains, the blaCTX-M ESBLs were dominant (83% of ESC-R E. coli strains), and the worldwide pandemic ST-131 clone was frequent (45% of ESC-R E. coli strains). In our low-prevalence setting, ESC-R among community-onset E. coli strains may be associated with both “export” from health care facilities into the community and direct “import” into the community from high-prevalence regions. PMID:24468775

Ingram, Paul R.; Runnegar, Naomi; Pitman, Matthew C.; Freeman, Joshua T.; Athan, Eugene; Havers, Sally M.; Sidjabat, Hanna E.; Jones, Mark; Gunning, Earleen; De Almeida, Mary; Styles, Kaylene; Paterson, David L.

2014-01-01

339

Enzymatic glycosylation of the topical antibiotic mupirocin.  

PubMed

Mupirocin is a commercially available antibiotic that acts on bacterial isoleucyl-tRNA synthetase, thereby inhibiting protein synthesis and preventing bacterial infection. An in vitro glycosylation approach was applied to synthesize glycoside derivatives of mupirocin using different NDP-sugars and glycosyltransferase from Bacillus licheniformis. Ultra pressure liquid chromatography-photo diode array analyses of the reaction mixtures revealed the generation of product peak(s). The results were further supported by high-resolution quadruple time of flight electrospray ionization mass spectrometry analyses. The product purified from the reaction mixture with UDP-D-glucose was subjected to NMR analysis, and the structure was determined to be mupirocin 6-O-?-D-glucoside. Other glycoside analogs of mupirocin were determined based on high-resolution mass analyses. Antibacterial activity assays against Staphylococcus aureus demonstrated complete loss of antibacterial activity after glucosylation of mupirocin at the 6-hydroxyl position. PMID:25069899

Parajuli, Prakash; Pandey, Ramesh Prasad; Pokhrel, Anaya Raj; Ghimire, Gopal Prasad; Sohng, Jae Kyung

2014-11-01

340

[Action of antibiotics as signalling molecules].  

PubMed

It was thought that antibiotics should be produced by soil microorganisms to inhibit the growth of competitors in natural habitats. Yet it has been shown that antibiotics at subinhibitory concentrations may have a role as signalling molecules providing cell-to-cell communication in bacteria in the environment. Antibiotics modulate gene transcription and regulate gene expression in microbial populations. Subinhibitory concentrations of antibiotics may cause a number of phenotypic and genotypic changes in microorganisms. These transcription changes are dependent on the interaction of antibiotics with macromolecular receptors such as ribosome or RNA-polymerase. Antibiotic signalling and quorum-sensing system are important regulatory mechanisms in bacteria. It was demonstrated that antibiotics interfered with quorum-sensing system. PMID:25051715

Bulgakova, V G; Vinogradova, K A; Orlova, T I; Kozhevin, P A; Polin, A N

2014-01-01

341

Use of antibiotics in plant agriculture.  

PubMed

Antibiotics are essential for control of bacterial diseases of plants, especially fire blight of pear and apple and bacterial spot of peach. Streptomycin is used in several countries; the use of oxytetracycline, oxolinic acid and gentamicin is limited to only a few countries. Springtime antibiotic sprays suppress pathogen growth on flowers and leaf surfaces before infection; after infection, antibiotics are ineffective. Antibiotics are applied when disease risk is high, and consequently the majority of orchards are not treated annually. In 2009 in the United States, 16,465 kg (active ingredient) was applied to orchards, which is 0.12% of the total antibiotics used in animal agriculture. Antibiotics are active on plants for less than a week, and significant residues have not been found on harvested fruit. Antibiotics have been indispensable for crop protection in the United States for more than 50 years without reports of adverse effects on human health or persistent impacts on the environment. PMID:22849276

Stockwell, V O; Duffy, B

2012-04-01

342

Is Clostridium difficile associated with the ‘4C’ antibiotics? A retrospective observational study in diabetic foot ulcer patients  

PubMed Central

Aims Clostridium difficile is an anaerobic cytotoxin-producing bacterium that can cause infectious diarrhoea, pseudomembranous colitis and toxic megacolon. The major risk factors for developing C. difficile infection include recent or current antimicrobial use, diabetes, age over 65, proton pump inhibitor use, immunosuppression and previous infection with C. difficile. Most diabetic foot ulcers are polymicrobial. Methods As a result guidelines advise treatment with broad spectrum antibiotics which include the ‘4C's’ (clindamycin, cephalosporins, co-amoxiclav and ciprofloxacin) which are associated with a higher risk of C. difficile infection. Retrospective observational data (June 2008 to January 2012) for the diabetes foot ulcers were gathered from the Diabetes/Podiatry Clinic database in NHS Ayrshire and Arran and cross-matched with the NHS Ayrshire and Arran Microbiology database. There were 111 patients with mean age 59 years (range 24–94 years), 33 type 1 patients, 78 type 2 patients, mean duration of diabetes 16 years (6 months–37 years) and mean HbA1c 67 mmol/mol (54–108 mmol/mol) [8.3% (7.1–12%)]. Results The total number of days antimicrobials prescribed for all patients was 7938 (mean number of antimicrobial days per patient = 71.5 days). There was one case of C. difficile infection of 111 patients giving an incidence of 1.25 cases per 10,000 patient-days of antibiotics/1 case per 209 foot ulcers. Conclusions Large doses, numbers and greater duration of antibiotic therapy all result in a greater degree of normal gut flora depletion. It is possible that the alterations in gut flora in diabetic foot ulcer patients protect them from antibiotic-induced C. difficile overgrowth. PMID:24499256

Collier, A; McLaren, J; Godwin, J; Bal, A

2014-01-01

343

Occurrence and distribution of antibiotic-resistant bacteria and transfer of resistance genes in Lake Taihu.  

PubMed

The overuse of antibiotics has accelerated antibiotic resistance in the natural environment, especially fresh water, generating a potential risk for public health around the world. In this study, antibiotic resistance in Lake Taihu was investigated and this was the first thorough data obtained through culture-dependent methods. High percentages of resistance to streptomycin and ampicillin among bacterial isolates were detected, followed by tetracycline and chloramphenicol. Especially high levels of ampicillin resistance in the western and northern regions were illustrated. Bacterial identification of the isolates selected for further study indicated the prevalence of some opportunistic pathogens and 62.0% of the 78 isolates exhibited multiple antibiotic resistance. The presence of ESBLs genes was in the following sequence: bla(TEM) > bla(SHV) > bla(CTMX) and 38.5% of the isolates had a class I integrase gene. Of all tested strains, 80.8% were able to transfer antibiotic resistance through conjugation. We also concluded that some new families of human-associated ESBLs and AmpC genes can be found in natural environmental isolates. The prevalence of antibiotic resistance and the dissemination of transferable antibiotic resistance in bacterial isolates (especially in opportunistic pathogens) was alarming and clearly indicated the urgency of realizing the health risks of antibiotic resistance to human and animal populations who are dependent on Lake Taihu for water consumption. PMID:24240317

Yin, Qian; Yue, Dongmei; Peng, Yuke; Liu, Ying; Xiao, Lin

2013-01-01

344

High-dose methylprednisolone influences the physiology and virulence of Candida albicans ambiguously and enhances the candidacidal activity of the polyene antibiotic amphotericin B and the superoxide-generating agent menadione.  

PubMed

Although exposure of Candida albicans cells to high-dose (4 mM) methylprednisolone stimulated microbial growth, germination rate in serum and phospholipase release, it also promoted the recognition of C. albicans cells by polymorphonuclear leukocytes. Pretreatment of C. albicans cells with methylprednisolone did not result in any increase in the pathogenicity of the fungus in intraperitoneal and intravenous mouse assays. Therefore, the virulence of C. albicans is unlikely to increase in patients treated with comparably high-dose methylprednisolone on skin and mucosal membranes. Methylprednisolone treatments also increased the production of conjugated dienes and thiobarbituric acid-reactive substances, and the menadione sensitivity of C. albicans cells, which can be explained by a significant decrease in the specific activities of several antioxidant enzymes. The combination of methylprednisolone with oxidants, e.g. in topical applications, may be of clinical importance when the predisposition to candidiasis is high. Methylprednisolone treatments negatively affected membrane fluidity and decreased the antifungal effects of both the polyene antibiotic nystatin and the ergosterol biosynthesis inhibitor lovastatin, and also enhanced the deleterious effects of the polyene antimycotic amphotericin B on C. albicans cells. These corticosteroid-polyene drug interactions should be considered in the treatment of C. albicans infections in patients with prolonged topical application of corticosteroids. PMID:17266730

Gyetvai, Agnes; Emri, Tamás; Fekete, Andrea; Varga, Zsuzsa; Gazdag, Zoltán; Pesti, Miklós; Belágyi, József; Emõdy, Levente; Pócsi, István; Lenkey, Béla

2007-03-01

345

Update on the cefdinir spectrum and potency against pathogens isolated from uncomplicated skin and soft tissue infections in North America: are we evaluating the orally administered cephalosporins correctly?  

Microsoft Academic Search

The spectrum and potency of cefdinir, an orally administered cephalosporin, was reevaluated for the uncomplicated skin and soft tissue infection (uSSTI) indication using contemporary isolates from 2004 to 2005. Cefdinir continues to have high rates of susceptibility against methicillin-susceptible staphylococci (100.0%), ?-hemolytic streptococci (groups A and B; 100.0%), viridans group streptococci (88.9%), Escherichia coli (93.2%), and Klebsiella pneumoniae (90.0%). No

Ronald N. Jones; Helio S. Sader

2006-01-01

346

The cefT gene of Acremonium chrysogenum C10 encodes a putative multidrug efflux pump protein that significantly increases cephalosporin C production  

Microsoft Academic Search

Transcriptional analysis of the region downstream of the pcbAB gene (which encodes the !-aminoadipyl-cysteinyl-valine synthetase involved in cephalosporin synthesis) of Acremonium chrysogenum revealed the presence of two different transcripts corresponding to two new ORFs. ORF3 encodes a putative D-hydroxyacid dehydrogenase and cefT (for transmembrane protein) encodes a multidrug efflux pump belonging to the Major Faciltator Superfamily (MFS) of membrane proteins.

R. Ullán; G. Liu; J. Casqueiro; S. Gutiérrez; O. Bañuelos; J. Martín

2002-01-01

347

Microbes : too smart for antibiotics?  

NSDL National Science Digital Library

This lesson packet builds on a peer-reviewed article about antibiotic resistance in microorganisms. The packet contains discussion questions about the article, instructions for an activity about hand washing that uses fake, fluorescent 'germs,' and two handouts of ideas for student activities. The first handout is appropriate for general biology students, and the second is designed for advanced, AP, or first-year undergraduate students. In many of the activities, students create a product, such as a public service announcement about antibiotic resistance (at the general level) or a funny presentation of the ways that bacteria can swap DNA (at the advanced level). The packet also provides correlations to national science standards and a suggested timetable for the activities. Copyright 2005 Eisenhower National Clearinghouse

Deichstetter, Peggy

2002-01-01

348

Super Bug Antibiotics and Evolution  

NSDL National Science Digital Library

Sam, a pre-med college student, routinely gets dialysis and develops a urinary tract infection. The infection is from a bacterium that the news media is calling a "superbug" from India. Sam does some internet searches to find out more information about his condition. He examines popular news stories, primary literature, and considers what the United States should do about the increased prevalence of antibiotic resistance. To explore this issue, students form groups in which they are a politician, a parent, or a doctor, with each student bringing different information to the discussion. The case also discusses evolutionary principles and how they connect to antibiotic resistance. The case was developed for an introductory biology course taken by science majors who are not majoring in biology. It could be used in any introductory biology course or even as an introduction for a specific course on evolution.

Wilson, Kristy J.

2011-01-01

349

Orally Active Carbapenem Antibiotics I  

Microsoft Academic Search

In order to design orally active carbapenem antibiotics effective against ?-lactam-resistant pathogens, such as penicillin-resistant Streptococcus pneumoniae (PRSP) and ?-lactamase non-producing ampicillin-resistant Haemophilus influenzae (BLNAR), a series of novel 2-phenylcarbapenems and some 2-thienyl derivatives were synthesized and tested for antibacterial activities. These compounds were highly active against PRSP, BLNAR, and major Gram-positive and Gram-negative bacteria that cause community-acquired infections. Their

Makoto Sunagawa; Yutaka Ueda; Shin-ichiro Okada; Shoji Watanabe; Takahiko Hashizuka; Seiji Hori; Akira Sasaki; Yoshiro Eriguchi; Katsunori Kanazawa

2005-01-01

350

Perioperative Antibiotics for Otologic Surgery  

Microsoft Academic Search

A computerized PubMed search of MEDLINE 1966-November 2004 was performed. Articles mapping to any of the following medical\\u000a subject headings were exploded and combined: “antibiotic prophylaxis,” “antibacterial agents,” “lactams,” “fluoroquinolones,”\\u000a “macrolides,” “clindamycin.” These articles were then cross-referenced with those mapping to either the exploded medical subject\\u000a heading “myringoplasty” or textword “myringoplasty.” This process yielded 21 trials. These articles were then

Jennifer J. Shin; Marlene Durand

351

Antibiotics and the gut microbiota.  

PubMed

Antibiotics have been a cornerstone of innovation in the fields of public health, agriculture, and medicine. However, recent studies have shed new light on the collateral damage they impart on the indigenous host-associated communities. These drugs have been found to alter the taxonomic, genomic, and functional capacity of the human gut microbiota, with effects that are rapid and sometimes persistent. Broad-spectrum antibiotics reduce bacterial diversity while expanding and collapsing membership of specific indigenous taxa. Furthermore, antibiotic treatment selects for resistant bacteria, increases opportunities for horizontal gene transfer, and enables intrusion of pathogenic organisms through depletion of occupied natural niches, with profound implications for the emergence of resistance. Because these pervasive alterations can be viewed as an uncoupling of mutualistic host-microbe relationships, it is valuable to reconsider antimicrobial therapies in the context of an ecological framework. Understanding the biology of competitive exclusion, interspecies protection, and gene flow of adaptive functions in the gut environment may inform the design of new strategies that treat infections while preserving the ecology of our beneficial constituents. PMID:25271726

Modi, Sheetal R; Collins, James J; Relman, David A

2014-10-01

352

Elimination of quinolone antibiotic carryover through use of antibiotic-removal beads.  

PubMed Central

To prove the utility of antibiotic-removal beads in separating antibiotics from bacterial samples, Escherichia coli ATCC 25922 was exposed to five separate quinolones before and after each was exposed to antibiotic-removal beads. Plates treated with antibiotic solutions that were exposed to beads demonstrated antibiotic removal, and plates treated with antibiotic solutions that were not exposed to beads demonstrated antibiotic carryover. After exposure to beads, fluoroquinolone concentrations decreased from 5 micrograms/ml to 0.14 micrograms/ml (ciprofloxacin), 0.04 micrograms/ml (temafloxacin), < 0.01 microgram/ml (ofloxacin), < 0.01 microgram/ml (sparfloxacin), and 0.02 micrograms/ml (clinafloxacin). These data indicate that antibiotic carryover can be successfully circumvented through the use of antibiotic-removal beads. Images PMID:8328791

Zabinski, R A; Larsson, A J; Walker, K J; Gilliland, S S; Rotschafer, J C

1993-01-01

353

Antibiotic Modification of Native Grafts: Improving upon nature's scaffolds  

NASA Astrophysics Data System (ADS)

The use of allograft bone in orthopaedics, spine surgery and dentistry is invaluable for helping restore bone defects and promote osteointegration. However, one, and perhaps the most important, problem associated with the use of allograft is infection. It is a devastating complication for patients and physicians alike, and necessitates repeated surgeries, extended treatment and often times results in increased morbidity and poor outcomes. Previous attempts to incorporate antibiotics into allograft by soaking the graft in antibiotic solution have enjoyed limited success in providing adequate protection against bacterial colonization. To overcome problems associated with controlled release systems, I have described a novel chemical modification that allows for the attachment of vancomycin, or other antibiotics, to free amines of allograft bone thus rendering the graft bactericidal over a long time period. This modification, as evaluated by immunohistochemistry, allowed for the uniform and stable attachment of antibiotics to allograft without adversely affecting its potential for incorporation with bone. Modified allograft, placed in the presence of S. aureus, did not allow colonization by bacteria as evaluated by fluorescent imaging, scanning microscopy, and direct bacterial counts. More importantly, inhibition of bacterial colonization resulted in prevention of biofilm formation. Furthermore, I show that the spectrum of activity of the parent antibiotic was maintained, as the construct was not active against E. coli challenges. Comparison of this technology with simple antibiotic incorporation demonstrated that the covalently-coupled antibiotic did not elute from the bone, but rather remained attached and active on the surface for times out to one year, times that are far longer than currently can be achieved with the elution technologies. Despite its potent activity against bacteria, modified bone remained biocompatible allowing attachment of osteoblastic-like cells with no increased toxicity. Furthermore, the antibiotic-modified allograft incorporated well into tibial defects in the rat. Finally, this construct was efficacious in decreasing the severity of infection and host reaction when impacted in an in vivo model of allograft-associated infection. Thus, our proposed modification in surface design serves as a starting point for the development of a new generation of bone grafts that are biologically active at sites of physiological importance.

Ketonis, Constantinos

354

Antibacterial activities in vitro and in vivo and pharmacokinetics of cefquinome (HR 111V), a new broad-spectrum cephalosporin.  

PubMed Central

Cefquinome is a new injectable aminothiazolyl cephalosporin derivative. It is stable against chromosomally and plasmid-encoded beta-lactamases and has a broad antibacterial spectrum. Staphylococcus aureus, streptococci, Pseudomonas aeruginosa, and members of the family Enterobacteriaceae (Escherichia coli, Salmonella spp., Klebsiella spp., Enterobacter spp., Citrobacter spp., and Serratia marcescens) are inhibited at low concentrations. Cefquinome is also active against many strains of methicillin-resistant staphylococci and enterococci. Its in vitro activity against gram-negative anaerobes is very limited. The high in vitro activity of cefquinome is reflected by its high in vivo efficacy against experimental septicemia due to different gram-positive and gram-negative bacteria. We studied the pharmacokinetic properties of cefquinome in mice, dogs, pigs, and calves. After single parenteral administrations, cefquinome displayed high peak levels, declining with half-lives of about 0.5, 0.9, 1.2, and 1.3 h, respectively. The areas under the concentration-time curve determined for dogs and mice showed linear correlations to the given doses. In dogs the urinary recovery was more than 70% within 24 h of dosing. Images PMID:2014969

Limbert, M; Isert, D; Klesel, N; Markus, A; Seeger, K; Seibert, G; Schrinner, E

1991-01-01

355

National campaigns to improve antibiotic use.  

PubMed

High levels of antibiotic consumption are driving levels of bacterial resistance that threaten public health. Nonetheless, antibiotics still provide highly effective treatments for common diseases with important implications for human health. The challenge for public education is to achieve a meaningful reduction in unnecessary antibiotic use without adversely affecting the management of bacterial infections. This paper focuses on the lessons learned from national campaigns in countries (Belgium and France) with high antibiotic use. Evaluation of these national campaigns showed the importance of television advertising as a powerful medium to change attitudes and perhaps also behaviour with regard to antibiotics. Moreover, in both countries, strong evidence suggested reduced antibiotic prescribing. However, adverse effects associated with a reduction in antibiotic prescribing were not monitored. We conclude that carefully designed mass education campaigns could improve antibiotic use nationally and should be considered in countries with high antibiotic use. However, these campaigns should employ techniques of social marketing and use appropriate outcome measures. The benefits and risks of such campaigns have been less well established in countries where antibiotic use is already low or declining. PMID:16568344

Goossens, Herman; Guillemot, Didier; Ferech, Matus; Schlemmer, Benoit; Costers, Michiel; van Breda, Marije; Baker, Lee J; Cars, Otto; Davey, Peter G

2006-05-01

356

Genome Sequencing of a Neisseria gonorrhoeae Isolate of a Successful International Clone with Decreased Susceptibility and Resistance to Extended-Spectrum Cephalosporins  

PubMed Central

The recent emergence of Neisseria gonorrhoeae strains with decreased susceptibility to extended-spectrum cephalosporins is a major concern globally. We sequenced the genome of an N. gonorrhoeae multiantigen sequence typing (NG-MAST) ST1407 isolate (SM-3) with decreased susceptibility and resistance to oral extended-spectrum cephalosporins. The isolate was cultured in 2008 in San Francisco, CA, and possessed mosaic penA allele XXXIV, which is associated with an international clone that possesses decreased susceptibility as well as resistance to oral extended-spectrum cephalosporins globally. The genome sequence of strain NCCP11945 was used as a scaffold, and our assembly resulted in 91 contigs covering 2,029,064 bp (91%; >150× coverage) of the genome. Numerous instances of suspected horizontal genetic transfer events with other Neisseria species were identified, and two genes, opa and txf, acquired from nongonococcal Neisseria species, were identified. Strains possessing mosaic penA alleles (n = 108) and nonmosaic penA alleles (n = 169) from the United States and Europe (15 countries), cultured in 2002 to 2009, were screened for the presence of these genes. The opa gene was detected in most (82%) penA mosaic-containing isolates (mainly from 2007 to 2009) but not in any penA nonmosaic isolates. The txf gene was found in all strains containing opa but also in several (18%) penA nonmosaic strains. Using opa and txf as genetic markers, we identified a strain that possesses mosaic penA allele XXXIV, but the majority of its genome is not genetically related to strain SM-3. This implies that penA mosaic allele XXXIV was transferred horizontally. Such isolates also possessed decreased susceptibility and resistance to oral extended-spectrum cephalosporins. These findings support that genetic screening for particular penA mosaic alleles can be a valuable method for tracking strains with decreased susceptibility as well as resistance to oral extended-spectrum cephalosporins worldwide and that screening using only NG-MAST may not be sufficient. PMID:22908152

Wu, Abel; Golparian, Daniel; Esmaili, Sarah; Pandori, Will; Sena, Emilee; Klausner, Jeffrey D.; Barry, Pennan; Unemo, Magnus; Pandori, Mark

2012-01-01

357

Genome sequencing of a Neisseria gonorrhoeae isolate of a successful international clone with decreased susceptibility and resistance to extended-spectrum cephalosporins.  

PubMed

The recent emergence of Neisseria gonorrhoeae strains with decreased susceptibility to extended-spectrum cephalosporins is a major concern globally. We sequenced the genome of an N. gonorrhoeae multiantigen sequence typing (NG-MAST) ST1407 isolate (SM-3) with decreased susceptibility and resistance to oral extended-spectrum cephalosporins. The isolate was cultured in 2008 in San Francisco, CA, and possessed mosaic penA allele XXXIV, which is associated with an international clone that possesses decreased susceptibility as well as resistance to oral extended-spectrum cephalosporins globally. The genome sequence of strain NCCP11945 was used as a scaffold, and our assembly resulted in 91 contigs covering 2,029,064 bp (91%; >150× coverage) of the genome. Numerous instances of suspected horizontal genetic transfer events with other Neisseria species were identified, and two genes, opa and txf, acquired from nongonococcal Neisseria species, were identified. Strains possessing mosaic penA alleles (n = 108) and nonmosaic penA alleles (n = 169) from the United States and Europe (15 countries), cultured in 2002 to 2009, were screened for the presence of these genes. The opa gene was detected in most (82%) penA mosaic-containing isolates (mainly from 2007 to 2009) but not in any penA nonmosaic isolates. The txf gene was found in all strains containing opa but also in several (18%) penA nonmosaic strains. Using opa and txf as genetic markers, we identified a strain that possesses mosaic penA allele XXXIV, but the majority of its genome is not genetically related to strain SM-3. This implies that penA mosaic allele XXXIV was transferred horizontally. Such isolates also possessed decreased susceptibility and resistance to oral extended-spectrum cephalosporins. These findings support that genetic screening for particular penA mosaic alleles can be a valuable method for tracking strains with decreased susceptibility as well as resistance to oral extended-spectrum cephalosporins worldwide and that screening using only NG-MAST may not be sufficient. PMID:22908152

Hess, David; Wu, Abel; Golparian, Daniel; Esmaili, Sarah; Pandori, Will; Sena, Emilee; Klausner, Jeffrey D; Barry, Pennan; Unemo, Magnus; Pandori, Mark

2012-11-01

358

Reversing Bacterial Resistance to Antibiotics by Phage-Mediated Delivery of Dominant Sensitive Genes  

PubMed Central

Pathogen resistance to antibiotics is a rapidly growing problem, leading to an urgent need for novel antimicrobial agents. Unfortunately, development of new antibiotics faces numerous obstacles, and a method that resensitizes pathogens to approved antibiotics therefore holds key advantages. We present a proof of principle for a system that restores antibiotic efficiency by reversing pathogen resistance. This system uses temperate phages to introduce, by lysogenization, the genes rpsL and gyrA conferring sensitivity in a dominant fashion to two antibiotics, streptomycin and nalidixic acid, respectively. Unique selective pressure is generated to enrich for bacteria that harbor the phages carrying the sensitizing constructs. This selection pressure is based on a toxic compound, tellurite, and therefore does not forfeit any antibiotic for the sensitization procedure. We further demonstrate a possible way of reducing undesirable recombination events by synthesizing dominant sensitive genes with major barriers to homologous recombination. Such synthesis does not significantly reduce the gene's sensitization ability. Unlike conventional bacteriophage therapy, the system does not rely on the phage's ability to kill pathogens in the infected host, but instead, on its ability to deliver genetic constructs into the bacteria and thus render them sensitive to antibiotics prior to host infection. We believe that transfer of the sensitizing cassette by the constructed phage will significantly enrich for antibiotic-treatable pathogens on hospital surfaces. Broad usage of the proposed system, in contrast to antibiotics and phage therapy, will potentially change the nature of nosocomial infections toward being more susceptible to antibiotics rather than more resistant. PMID:22113912

Edgar, Rotem; Friedman, Nir; Molshanski-Mor, Shahar

2012-01-01

359

Enhancement of secondary metabolite production using the antibiotic gradient-plate technique.  

PubMed

We have used the antibiotic gradient-plate technique to generate antifungal producing Actinomadura strains that synthesize enhanced quantities of component 3A of a macrocyclic lactam antifungal compound Sch 38516. Seventy-nine colonies were selected from a mixture of rifampicin and spectinomycin gradient plates. The two fermentation extracts described produced an enhanced 3A component (identified with silica gel TLC, HPLC, and bioautography) when compared to the parent culture isolate extracts (no antibiotic selection). PMID:1531080

Gentile, F A; Mayles, B A; Procopio, P L

1992-01-01

360

Protection by antibiotics against myeloperoxidase-dependent cytotoxicity to lung epithelial cells in vitro.  

PubMed Central

Myeloperoxidase, in the presence of noncytotoxic concentrations of H2O2, was used to induce cytotoxicity to the lung epithelial cell line, AKD. When the cationic aminoglycosides, tobramycin and gentamicin were added to the cells in the presence of myeloperoxidase and H2O2, cytotoxicity was completely inhibited. In addition, tobramycin prevented cytotoxicity induced by cystic fibrosis sputum and H2O2. Protection against myeloperoxidase and H2O2 was also observed with the thioether-containing antibiotics, ticarcillin and ceftazidime, but at higher concentrations than with the aminoglycosides. Analysis of spectral properties, dimethylsulfoxide-mediated reduction, and ethyl acetate/NaCl partitioning, demonstrated that aminoglycosides converted HOCl to hydrophilic noncytotoxic chloramines, but were unable to prevent the oxidation of sulfhydryls and methionine by HOCl. In contrast, ticarcillin and ceftazidime were highly effective inhibitors of HOCl-mediated sulfhydryl and methionine oxidation. These results suggest that aminoglycosides protect lung epithelial cells against myeloperoxidase-dependent oxidant injury by binding to anionic cell surfaces and converting HOCl to hydrophilic noncytotoxic chloramines, whereas penicillins and cephalosporins are potent HOCl scavengers capable of protecting critical extracellular molecules against oxidation. PMID:8380814

Cantin, A; Woods, D E

1993-01-01

361

Factors affecting the cost effectiveness of antibiotics.  

PubMed

In an era of spiraling health care costs and limited resources, policy makers and health care payers are concerned about the cost effectiveness of antibiotics. The aim of this study is to draw on published economic evaluations with a view to identify and illustrate the factors affecting the cost effectiveness of antibiotic treatment of bacterial infections. The findings indicate that the cost effectiveness of antibiotics is influenced by factors relating to the characteristics and the use of antibiotics (i.e., diagnosis, comparative costs and comparative effectiveness, resistance, patient compliance with treatment, and treatment failure) and by external factors (i.e., funding source, clinical pharmacy interventions, and guideline implementation interventions). Physicians need to take into account these factors when prescribing an antibiotic and assess whether a specific antibiotic treatment adds sufficient value to justify its costs. PMID:22312550

Simoens, Steven

2011-01-01

362

Factors Affecting the Cost Effectiveness of Antibiotics  

PubMed Central

In an era of spiraling health care costs and limited resources, policy makers and health care payers are concerned about the cost effectiveness of antibiotics. The aim of this study is to draw on published economic evaluations with a view to identify and illustrate the factors affecting the cost effectiveness of antibiotic treatment of bacterial infections. The findings indicate that the cost effectiveness of antibiotics is influenced by factors relating to the characteristics and the use of antibiotics (i.e., diagnosis, comparative costs and comparative effectiveness, resistance, patient compliance with treatment, and treatment failure) and by external factors (i.e., funding source, clinical pharmacy interventions, and guideline implementation interventions). Physicians need to take into account these factors when prescribing an antibiotic and assess whether a specific antibiotic treatment adds sufficient value to justify its costs. PMID:22312550

Simoens, Steven

2011-01-01

363

Production of `hybrid' antibiotics by genetic engineering  

Microsoft Academic Search

The recent development of molecular cloning systems in Streptomyces1-4 has made possible the isolation of biosynthetic genes for some of the many antibiotics produced by members of this important genus of bacteria5-10. Such clones can now be used to test the idea that novel antibiotics could arise through the transfer of biosynthetic genes between streptomycetes producing different antibiotics11. The likelihood

D. A. Hopwood; F. Malpartida; H. M. Kieser; H. Ikeda; J. Duncan; I. Fujii; B. A. M. Rudd; H. G. Floss; S. Omura

1985-01-01

364

Consumer Attitudes and Use of Antibiotics  

Microsoft Academic Search

Recent antibiotic use is a risk factor for infection or col- onization with resistant bacterial pathogens. Demand for antibiotics can be affected by consumers' knowledge, atti- tudes, and practices. In 1998-1999, the Foodborne Diseases Active Surveillance Network (FoodNet) conduct- ed a population-based, random-digit dialing telephone sur- vey, including questions regarding respondents' knowl- edge, attitudes, and practices of antibiotic use. Twelve

Jodi Vanden Eng; Ruthanne Marcus; James L. Hadler; Beth Imhoff; Duc J. Vugia; Paul R. Cieslak; Elizabeth Zell; Valerie Deneen; Katherine Gibbs McCombs; Shelley M. Zansky; Marguerite A. Hawkins; Richard E. Besser

2003-01-01

365

Antibiotics  

NASA Astrophysics Data System (ADS)

A 28-year-old man was transferred to our hospital and underwent surgery for resection of an aortic graft infected with Klebsiella pneumoniae. Antimicrobial therapy consisted of amikacin, cefazolin, chloramphenicol, sulfamethoxazole, and trimethoprim. A request for amikacin and sulfamethoxazole assays was received by the laboratory along with information that the patient had received tobramycin until 24 h before the serum was obtained.

Anhalt, John P.

366

Antibiotic residues in food: the African scenario.  

PubMed

Antibiotics are substances either produced naturally by living organisms or synthetically in the laboratory, and they are able to kill or inhibit the growth of microorganisms. Antibiotics are also used as feed additives for the purpose of livestock health maintenance. Antibiotic residues in feedstuffs are currently a problem of some magnitude in different parts of the world, particularly due to associated public health concerns that include hypersensitivity reactions, antibiotic resistance, toxicity, teratogenicity, and carcinogenicity. In Africa, as in other parts of the world, antibiotic residues in animal-derived foods have been extensively recorded in many African countries; these residues have exceeded the WHO maximum residue levels in many cases. It has been reported that tetracyclines are the most predominantly prescribed antibiotics in Africa, and of all antibiotic-associated residues they represent 41% of cases, followed by beta-lactams at 18%. Great care should be taken to monitor antibiotic cessation periods before the release of animal-derived foods for human consumption. In addition, strict legislation should be implemented in order to minimize the abuse of antibiotics. PMID:23631148

Darwish, Wageh Sobhy; Eldaly, Elsaid A; El-Abbasy, Mohamed Tharwat; Ikenaka, Yoshinori; Nakayama, Shouta; Ishizuka, Mayumi

2013-02-01

367

Treating children without antibiotics in primary healthcare.  

PubMed

The overuse of antibiotics in children is becoming a major public health problem. Although most of the common childhood infections such as diarrhea and upper respiratory tract infections are caused by viruses, large volumes of antibiotics are prescribed for these infections in children in the primary care settings. Excessive use of antibiotics is the fundamental risk factor for the development of antibiotic resistance. It is estimated that 90% of upper respiratory tract infections are self limiting viral illnesses and even bacterial infections like acute otitis media often run a self limiting course. Clinical trials have shown that antibiotic use to treat common upper respiratory tract infections like sore throat, nasopharyngitis and otitis media has no or minimal benefit on the clinical outcome. This report discusses two strategies considered to reduce the use of antibiotic in these conditions: i) No prescription, and ii) Delayed prescription of antibiotics for common upper respiratory tract infections. Moreover, this report calls for a significant modification of the prescribing habits of physicians, and to also extend community awareness on the harms of the misuse and overuse of antibiotics. It is imperative to educate health workers as well as the Community in a coordinated and sustainable manner about the growing public health problem of antibiotic resistance. PMID:22125722

Kutty, Narayanan

2011-09-01

368

Treatment of infectious disease: beyond antibiotics.  

PubMed

Several antibiotics have been discovered following the discovery of penicillin. These antibiotics had been helpful in treatment of infectious diseases considered dread for centuries. The advent of multiple drug resistance in microbes has posed new challenge to researchers. The scientists are now evaluating alternatives for combating infectious diseases. This review focuses on major alternatives to antibiotics on which preliminary work had been carried out. These promising anti-microbial include: phages, bacteriocins, killing factors, antibacterial activities of non-antibiotic drugs and quorum quenching. PMID:24661689

Nigam, Anshul; Gupta, Divya; Sharma, Ashwani

2014-01-01

369

The Use and Abuse of Antibiotics and the Development of Antibiotic Resistance  

Microsoft Academic Search

\\u000a The growing problem of antibiotic resistance has made the formerly routine therapy of many infectious diseases challenging,\\u000a and, in rare cases, impossible. The widespread nature of the problem has led some experts to speculate about a “post-antibiotic\\u000a era.” Furthermore, though antibiotic resistance occurs in nature and is an inevitable consequence of even the most prudent\\u000a antibiotic use, it is clear

B. Keith English; Aditya H. Gaur

370

Synthesis, optimization, and characterization of silver nanoparticles from Acinetobacter calcoaceticus and their enhanced antibacterial activity when combined with antibiotics  

PubMed Central

Background The development of nontoxic methods of synthesizing nanoparticles is a major step in nanotechnology to allow their application in nanomedicine. The present study aims to biosynthesize silver nanoparticles (AgNPs) using a cell-free extract of Acinetobacter spp. and evaluate their antibacterial activity. Methods Eighteen strains of Acinetobacter were screened for AgNP synthesis. AgNPs were characterized using various techniques. Reaction parameters were optimized, and their effect on the morphology of AgNPs was studied. The synergistic potential of AgNPs on 14 antibiotics against seven pathogens was determined by disc-diffusion, broth-microdilution, and minimum bactericidal concentration assays. The efficacy of AgNPs was evaluated as per the minimum inhibitory concentration (MIC) breakpoints of the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results Only A. calcoaceticus LRVP54 produced AgNPs within 24 hours. Monodisperse spherical nanoparticles of 8–12 nm were obtained with 0.7 mM silver nitrate at 70°C. During optimization, a blue-shift in ultraviolet-visible spectra was seen. X-ray diffraction data and lattice fringes (d =0.23 nm) observed under high-resolution transmission electron microscope confirmed the crystallinity of AgNPs. These AgNPs were found to be more effective against Gram-negative compared with Gram-positive microorganisms. Overall, AgNPs showed the highest synergy with vancomycin in the disc-diffusion assay. For Enterobacter aerogenes, a 3.8-fold increase in inhibition zone area was observed after the addition of AgNPs with vancomycin. Reduction in MIC and minimum bactericidal concentration was observed on exposure of AgNPs with antibiotics. Interestingly, multidrug-resistant A. baumannii was highly sensitized in the presence of AgNPs and became susceptible to antibiotics except cephalosporins. Similarly, the vancomycin-resistant strain of Streptococcus mutans was also found to be susceptible to antibiotic treatment when AgNPs were added. These biogenic AgNPs showed significant synergistic activity on the ?-lactam class of antibiotics. Conclusion This is the first report of synthesis of AgNPs using A. calcoaceticus LRVP54 and their significant synergistic activity with antibiotics resulting in increased susceptibility of multidrug-resistant bacteria evaluated as per MIC breakpoints of the CLSI standard. PMID:24235826

Singh, Richa; Wagh, Priyanka; Wadhwani, Sweety; Gaidhani, Sharvari; Kumbhar, Avinash; Bellare, Jayesh; Chopade, Balu Ananda

2013-01-01

371

Identification of Multiresistant Salmonella Isolates Capable of Subsisting on Antibiotics?  

PubMed Central

This study assessed the ability of Salmonella (572 isolates) to subsist on 12 different antibiotics. The majority (11/12) of the antibiotics enabled subsistence for at least 1 of 140 isolates. Furthermore, 40 isolates were able to subsist on more than one antibiotic. Antibiotic resistance and antibiotic subsistence do not appear to be equivalent. PMID:20173063

Barnhill, Alison E.; Weeks, Katherine E.; Xiong, Nalee; Day, Tim A.; Carlson, Steve A.

2010-01-01

372

Reducing Parental Demand for Antibiotics by Promoting Communication Skills  

ERIC Educational Resources Information Center

Antibiotic-resistant strains of bacteria are continuing to emerge as high rates of antibiotic use persist. Children are among the highest users of antibiotics, with parents influencing physician decision-making regarding antibiotic prescription. An intervention based on Social Cognitive Theory (SCT) to reduce parents' expectations for antibiotics

Alder, Stephen C.; Trunnell, Eric P.; White, George L., Jr.; Lyon, Joseph L.; Reading, James P.; Samore, Matthew H.; Magill, Michael K.

2005-01-01

373

UTILIZATION OF RESTRICTED ANTIBIOTICS IN A UNIVERSITY HOSPITAL IN THAILAND  

Microsoft Academic Search

Antibiotic resistance, a major negative consequence of antibiotic overuse, is an im- portant problem worldwide. Various means have been used to control antibiotic usage including the use of an antibiotic order form (AOF), restricted antibiotic formularies and provision of educational information. The present study was designed to evaluate the use of antimicrobials in a 1,000-bed university hospital. Antimicrobial agents, likely

Sasima Kusuma Na Ayuthya; Oraphan P Matangkasombut; Sayomporn Sirinavin; Kumthorn Malathum; Boonmee Sathapatayavongs

374

Uptake of the cephalosporin, cephalexin, by a dipeptide transport carrier in the human intestinal cell line, Caco-2.  

PubMed

The transport of the orally absorbed cephalosporin, cephalexin, was examined in the human epithelial cell line, Caco-2 that possesses intestinal enterocyte-like properties when cultured. In sodium-free buffer, the cells accumulated 1 mM D-[9-14C]cephalexin against a concentration gradient and obtained a distribution ratio of 3.5 within 180 min. Drug uptake was maximal when the extracellular pH was 6.0. Uptake was reduced by metabolic inhibitors and by protonophores indicating that uptake was energy- and proton-dependent. Kinetic analysis of the concentration dependence of the rate of cephalexin uptake showed that a non-saturable component (Kd of 0.18 +/- 0.01 nmol/min per mg protein per mM) and a transport system with a Km of 7.5 +/- 2.8 mM and a Vmax of 6.5 +/- 0.9 nmol/min per mg protein were responsible for drug uptake. Uptake was competitively inhibited by dipeptides. The transport carrier exhibited stereospecificity for the L-isomer of cephalexin. Drug uptake was not affected by the presence of amino acids, organic anions, 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid or 4,4'-diisothiocyano-2,2'-disulfonic stilbene. Therefore, Caco-2 cells take up cephalexin by a proton-dependent dipeptide transport carrier that closely resembles the transporter present in the intestine. Caco-2 cells represent a cellular model for future studies of the dipeptide transporter. PMID:2397233

Dantzig, A H; Bergin, L

1990-09-01

375

In vitro activity of cephalosporin RWJ-54428 (MC-02479) against multidrug-resistant gram-positive cocci.  

PubMed

RWJ-54428 (MC-02479) is a novel cephalosporin that binds to penicillin-binding protein (PBP) PBP 2' (PBP 2a) of methicillin-resistant staphylococci. Its in vitro activity was assessed against 472 gram-positive cocci, largely selected as epidemiologically unrelated isolates with multidrug resistance. The MIC at which 50% of isolates are inhibited (MIC(50)) and MIC(90) of RWJ-54428 for methicillin-resistant Staphylococcus aureus (MRSA) were 1 and 2 microg/ml, respectively, whereas they were 0.5 and 0.5 microg/ml, respectively, for methicillin-susceptible S. aureus. The MIC(50) and MIC(90) were 1 and 4 microg/ml, respectively, for methicillin-resistant coagulase-negative staphylococci (MRCoNS), whereas they were 0.25 and 1 microg/ml, respectively, for methicillin-susceptible isolates. The highest MICs for MRSA and MRCoNS isolates were 2 and 4 microg/ml, respectively. The MIC(50) and MIC(90) of RWJ-54428 for Enterococcus faecalis were 0.5 and 1 microg/ml, respectively, but they were 4 and 8 microg/ml, respectively, for Enterococcus faecium. For penicillin-susceptible, -intermediate, and -resistant pneumococci, the MIC(90)s of RWJ-54428 were 0.03, 0.25, and 0.5 microg/ml, respectively, with the highest MIC for a pneumococcus being 1 microg/ml, recorded for a strain for which penicillin and cefotaxime MICs were 8 and 4 microg/ml. MICs for Lancefield group A, B, C, and G streptococci were < or =0.008 microg/ml; those for viridans group streptococci, including isolates not susceptible to penicillin, were from 0.015 to 0.5 microg/ml. RWJ-54428 did not select resistant mutants of MRSA or enterococci in challenge experiments and has the potential to be useful for the treatment of infections caused by gram-positive cocci. PMID:11796337

Johnson, Alan P; Warner, Marina; Carter, Michael; Livermore, David M

2002-02-01

376

In Vitro Activity of Cephalosporin RWJ-54428 (MC-02479) against Multidrug-Resistant Gram-Positive Cocci  

PubMed Central

RWJ-54428 (MC-02479) is a novel cephalosporin that binds to penicillin-binding protein (PBP) PBP 2? (PBP 2a) of methicillin-resistant staphylococci. Its in vitro activity was assessed against 472 gram-positive cocci, largely selected as epidemiologically unrelated isolates with multidrug resistance. The MIC at which 50% of isolates are inhibited (MIC50) and MIC90 of RWJ-54428 for methicillin-resistant Staphylococcus aureus (MRSA) were 1 and 2 ?g/ml, respectively, whereas they were 0.5 and 0.5 ?g/ml, respectively, for methicillin-susceptible S. aureus. The MIC50 and MIC90 were 1 and 4 ?g/ml, respectively, for methicillin-resistant coagulase-negative staphylococci (MRCoNS), whereas they were 0.25 and 1 ?g/ml, respectively, for methicillin-susceptible isolates. The highest MICs for MRSA and MRCoNS isolates were 2 and 4 ?g/ml, respectively. The MIC50 and MIC90 of RWJ-54428 for Enterococcus faecalis were 0.5 and 1 ?g/ml, respectively, but they were 4 and 8 ?g/ml, respectively, for Enterococcus faecium. For penicillin-susceptible, -intermediate, and -resistant pneumococci, the MIC90s of RWJ-54428 were 0.03, 0.25, and 0.5 ?g/ml, respectively, with the highest MIC for a pneumococcus being 1 ?g/ml, recorded for a strain for which penicillin and cefotaxime MICs were 8 and 4 ?g/ml. MICs for Lancefield group A, B, C, and G streptococci were ?0.008 ?g/ml; those for viridans group streptococci, including isolates not susceptible to penicillin, were from 0.015 to 0.5 ?g/ml. RWJ-54428 did not select resistant mutants of MRSA or enterococci in challenge experiments and has the potential to be useful for the treatment of infections caused by gram-positive cocci. PMID:11796337

Johnson, Alan P.; Warner, Marina; Carter, Michael; Livermore, David M.

2002-01-01

377

The role of aquatic ecosystems as reservoirs of antibiotic resistant bacteria and antibiotic resistance genes  

Microsoft Academic Search

The widespread and indiscriminate use of antibiotics has led to the development of antibiotic resistance in pathogenic, as well as commensal, microorganisms. Resistance genes may be horizontally or vertically transferred between bacterial communities in the environment. The recipient bacterial communities may then act as a reservoir of these resistance genes. In this study, we report the incidence of antibiotic resistance

P. T. Biyela; J. Lin; C. C. Bezuidenhout

378

Antibiotics and antibiotic-resistant bacteria in waters associated with a hospital in Ujjain, India  

Microsoft Academic Search

BACKGROUND: Concerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies

Vishal Diwan; Ashok J Tamhankar; Rakesh K Khandal; Shanta Sen; Manjeet Aggarwal; Yogyata Marothi; Rama V Iyer; Karin Sundblad-Tonderski; Cecilia Stålsby-Lundborg

2010-01-01

379

Structural basis of emerging antibiotic resistance Enzyme structural plasticity and emergence of broad spectrum antibiotic  

E-print Network

Structural basis of emerging antibiotic resistance 1 Enzyme structural plasticity and emergence of broad spectrum antibiotic resistance Frédérique Maurice1 , Isabelle Broutin1 , Isabelle Podglajen2 25 Running title : Structural basis of emerging antibiotic resistance Keywords : acetyltransferase

Paris-Sud XI, Université de

380

Aquatic photochemistry of nitrofuran antibiotics.  

PubMed

The aquatic photochemical degradation of a class of pharmaceuticals known as the nitrofuran antibiotics (furaltadone, furazolidone, and nitrofurantoin) was investigated. Direct photolysis is the dominant photodegradation pathway for these compounds with the formation of a photostationary state between the syn and the anti isomers occurring during the first minutes of photolysis. The direct photolysis rate constant and quantum yield were calculated for each of the three nitrofurans. Reaction rate constants with reactive oxygen species (ROS), 102 and *OH, were also measured, and half-lives were calculated using environmentally relevant ROS concentrations. Half-lives calculated for reaction with 1O2 and *OH are in the ranges of 120-1900 and 74-82 h, respectively. When compared to the direct photolysis half-lives, 0.080-0.44 h in mid-summer at 45 degrees N latitude, it is clear that indirect photochemical processes cannot compete with direct photolysis. The major photodegradation product of the nitrofurans was found to be nitrofuraldehyde, which is also photolabile. Upon photolysis, nitrofuraldehyde produces NO, which is easily oxidized to nitrous acid. The acid produced further catalyzes the photodegradation of the parent nitrofuran antibiotics, leading to autocatalytic behavior. Natural waters were found to buffer the acid formation. PMID:16999120

Edhlund, Betsy L; Arnold, William A; McNeill, Kristopher

2006-09-01

381

An In Vitro Study on the Effects of Nisin on the Antibacterial Activities of 18 Antibiotics against Enterococcus faecalis  

PubMed Central

Enterococcus faecalis rank among the leading causes of nosocomial infections worldwide and possesses both intrinsic and acquired resistance to a variety of antibiotics. Development of new antibiotics is limited, and pathogens continually generate new antibiotic resistance. Many researchers aim to identify strategies to effectively kill this drug-resistant pathogen. Here, we evaluated the effect of the antimicrobial peptide nisin on the antibacterial activities of 18 antibiotics against E. faecalis. The MIC and MBC results showed that the antibacterial activities of 18 antibiotics against E. faecalis OG1RF, ATCC 29212, and strain E were significantly improved in the presence of 200 U/ml nisin. Statistically significant differences were observed between the results with and without 200 U/ml nisin at the same concentrations of penicillin or chloramphenicol (p<0.05). The checkerboard assay showed that the combination of nisin and penicillin or chloramphenicol had a synergetic effect against the three tested E. faecalis strains. The transmission electron microscope images showed that E. faecalis was not obviously destroyed by penicillin or chloramphenicol alone but was severely disrupted by either antibiotic in combination with nisin. Furthermore, assessing biofilms by a confocal laser scanning microscope showed that penicillin, ciprofloxacin, and chloramphenicol all showed stronger antibiofilm actions in combination with nisin than when these antibiotics were administered alone. Therefore, nisin can significantly improve the antibacterial and antibiofilm activities of many antibiotics, and certain antibiotics in combination with nisin have considerable potential for use as inhibitors of this drug-resistant pathogen. PMID:24586598

Ling, Junqi; Ma, Jinglei; Huang, Lijia; Zhang, Luodan

2014-01-01

382

Disrupting antibiotic resistance propagation by inhibiting the conjugative DNA relaxase  

PubMed Central

Conjugative transfer of plasmid DNA via close cell–cell junctions is the main route by which antibiotic resistance genes spread between bacterial strains. Relaxases are essential for conjugative transfer and act by cleaving DNA strands and forming covalent phosphotyrosine linkages. Based on data indicating that multityrosine relaxase enzymes can accommodate two phosphotyrosine intermediates within their divalent metal-containing active sites, we hypothesized that bisphosphonates would inhibit relaxase activity and conjugative DNA transfer. We identified bisphosphonates that are nanomolar inhibitors of the F plasmid conjugative relaxase in vitro. Furthermore, we used cell-based assays to demonstrate that these compounds are highly effective at preventing DNA transfer and at selectively killing cells harboring conjugative plasmids. Two potent inhibitors, clodronate and etidronate, are already clinically approved to treat bone loss. Thus, the inhibition of conjugative relaxases is a potentially novel antimicrobial approach, one that selectively targets bacteria capable of transferring antibiotic resistance and generating multidrug resistant strains. PMID:17630285

Lujan, Scott A.; Guogas, Laura M.; Ragonese, Heather; Matson, Steven W.; Redinbo, Matthew R.

2007-01-01

383

[A mass-spectrometric analysis of genetic markers of S. pneumoniae resistance to beta-lactam antibiotics].  

PubMed

Beta-lactam antibiotics remain the drugs of choice for treatment of S. pneumoniae infections in spite of growing level of resistance. The formation of S. pneumoniae resistance to these drugs is mediated by modifications of the penicillin-binding proteins (PBPs), the targets of the antibiotic action. A new approach to detection of mutations in PBP1A, 2B and 2X genes based on minisequencing reaction followed by MALDI-ToF (Matrix-Assisted Laser Desorption/Ionization Time of Flight) mass spectrometry was developed in this study. The evaluation of these mutations prevalence in clinical S. pneumoniae isolates (n = 194) with different susceptibility level to beta-lactam antibiotics was performed. Twenty-four different combinations of mutations in PBPs (genotypes) were detected. All isolates susceptible to penicillin (n = 49, MIC > or = 0.06 > or = gamma/ml) carried no mutations in all analyzed loci. For 145 S. pneumoniae isolates with reduced susceptibility to penicillin (MIC > 0.06 > or = gamma/ml) the mutations in PBPs were detected in 133 (91.7 %) cases that testify to high diagnostic sensitivity of such approach. The isolates with MIC > or = 4 > or = gamma/ml (n = 20) carried multiple mutations in all analyzed genes that confirms cumulative effects of penicillin resistance formation. However, it was not possible to associate observed mutations in PBPs genes with decrease of susceptibility to cefotaxime that allows suggesting the entire difference in molecular mechanisms of formation of resistance to penicillins and cephalosporins. The offered method of S. pneumoniae genotyping is suitable for susceptibility testing to penicillin of individual isolates and for molecular monitoring of the resistance determinants in population. PMID:20882772

Savinova, T A; Il'ina, E N; Sidorenko, S V

2010-01-01

384

The Evolution of Antibiotic Resistance within Patients  

Microsoft Academic Search

The study of the molecular mechanisms of antibiotic resistance has been very informative. It provides a backcloth against which an understanding of the properties of both microorganisms and antibiotics can be understood. In turn this understanding has led to changes in clinical practice, though not as rapidly in all countries as many would desire. In addition, it is clear that

Ian R. Booth

385

Antibiotic-Resistant Bacteria: There is Hope.  

ERIC Educational Resources Information Center

Argues that reduction in the use of antibiotics would enable antibiotic-sensitive bacteria to flourish. Presents an activity designed to show students how a small, seemingly unimportant difference in doubling time can, over a period of time, make an enormous difference in population size. (DDR)

Offner, Susan

1998-01-01

386

Antibiotic resistance among autochthonous aquatic environmental bacteria.  

PubMed

Antibiotics are widely used in both human and veterinary medicine and antibiotic-resistant bacteria cause problems in antibiotic therapy. The current study was conducted in the catchment area of the river Swist (Germany) and focuses on the resistance of environmental Rhodospirillaceae to antibiotics used in human medicine. The samples collected reflect different levels of human impact on the environment. In total, 614 isolates were tested for antibiotic susceptibility. About half of these isolates were susceptible to all substances tested. Oxacillin resistance was observed most frequently (41%). Resistant Rhodospirillaceae were detected in wastewater effluent from a municipal sewage treatment plant, as well as in non-polluted upper reaches. The highest multi-resistance level was detected in small tributaries and it surprisingly decreased with an increasing influence of municipal wastewater. It could be shown that the detected resistances were acquired rather than intrinsic. Besides natural occurrence of multi-resistance among non-sulphur purple bacteria, horizontal gene transfer and acquired cross-resistance against veterinary antibiotics are assumed to be important factors. To the authors' knowledge, this is the first study investigating the potential of Rhodospirillaceae as a reservoir for resistance to antibiotics used in human medicine. The consequence for resistance prevalence in human pathogens and for their antibiotic therapy needs evaluation. PMID:23128628

Schreiber, Christiane; Kistemann, Thomas

2013-01-01

387

Occurrence of antibiotics in the aquatic environment  

Microsoft Academic Search

The recent monitoring of drug residues in the aquatic environment has gained much interest as many pharmaceutical compounds can frequently be found in sewage treatment plant (STP) effluents and river water at concentrations up to several ?g\\/l. This article describes the analysis of various water samples for 18 antibiotic substances, from the classes of macrolid antibiotics, sulfonamides, penicillins and tetracyclines.

Roman Hirsch; Thomas Ternes; Klaus Haberer; Karl-Ludwig Kratz

1999-01-01

388

Antibiotic-resistance cassettes for Bacillus subtilis  

Microsoft Academic Search

The genes encoding resistance to four different antibiotics (erythromycin, kanamycin, tetracycline and spectinomycin) were cloned in the polylinker of various Escherichia coli plasmid vectors. These cassettes can be inserted into cloned Bacillus subtilis (Bs) genes and used to create tagged chromosomal disruptions after recombination into Bs and selection in the presence of the appropriate antibiotic.

Anne-Marie Guérout-Fleury; Kamran Shazand; Niels Frandsen; Patrick Stragier

1995-01-01

389

The biological cost of antibiotic resistance  

Microsoft Academic Search

The frequency and rates of ascent and dissemination of antibiotic resistance in bacterial populations are anticipated to be directly related to the volume of antibiotic use and inversely related to the cost that resistance imposes on the fitness of bacteria. The data available from recent laboratory studies suggest that most, but not all, resistance-determining mutations and accessory elements engender some

Dan I Andersson; Bruce R Levin

1999-01-01

390

[Rational antibiotic prescribing. Challenges and successes].  

PubMed

Rational and prudent antibiotic prescribing strategies are important both for the hospital sector as well as for ambulatory medicine. Prerequisites are the availability of antibiotic use and antibiotic resistance data and of infrastructure and trained personnel needed for implementing and evaluating antibiotic policies. Currently, these requirements are not being met sufficiently in Germany. A major challenge in this country is the lack of adequately trained and experienced personnel. On the other hand there are several projects and initiatives supported in part within the national antibiotic resistance control program which have produced some progress and success. One example is GERMAP, the national antibiotic use and resistance atlas covering both human medicine and the veterinary field. Other examples are the recently improved program for continuous hospital antibiotic use, surveillance and feedback and the Antibiotic Stewardship (ABS) training program with establishment of an ABS expert network. Future perspectives include programs for evaluation of practice guideline adherence and the development and evaluation of quality of care indicators. Intermediate and long-term investment is needed in specialty training and certification of a sufficient number of infectious disease physicians, medical microbiologists and infection control doctors/hospital epidemiologists and hospital pharmacists. PMID:23114441

Kern, W V; de With, K

2012-11-01

391

Inhaled antibiotics in mechanically ventilated patients.  

PubMed

During the last decade, inhaled antibiotics, especially colistin, has been widely used worldwide as a therapeutic option, supplementary to conventional intravenous antibiotics, for the treatment of multidrug-resistant (MDR) Gram-negative nosocomial and ventilator-associated pneumonia (VAP). Antimicrobial aerosols are commonly used in mechanically ventilated patients with VAP, although information regarding their efficacy and optimal technique of administration has been limited. Recent studies showed that the administration of inhaled antibiotics in addition to systemic antibiotics provided encouraging results associated with low toxicity for the management of VAP mainly due to MDR Gram negative bacteria. Although the theory behind aerosolized administration of antibiotics seems to be sound, there are limited data available to support the routine use of this modality since very few randomized controlled trials (RCTs) have still examined the efficacy of this approach in patients with VAP. Additionally, this route of antibiotic delivery has not been approved until now neither by the FDA nor by the European Medicines Agency (EMEA) in patients with VAP. However, since the problem of VAP due to MDR bacteria has been increased worldwide RCTs are urgently needed in order to prove the safety, efficiency and efficacy of inhaled antimicrobial agents administered alone or in conjunction with parenteral antibiotics for the management of VAP in critically ill patients. Indeed, more data are needed to establish the appropriate role of inhaled antibiotics for the treatment of VAP. PMID:24107830

Michalopoulos, A S; Falagas, M E

2014-02-01

392

Policies, Policies, Policies! What Antibiotic Policies Work?  

Microsoft Academic Search

ntibiotics should be used rationally in order to improve patient outcome; to contain the cost of treatment and most importantly to prevent the emergence of antibiotic resistance. Unfortunately, inappropriate use of antibiotics appears to be a universal phenomenon and numerous surveys from around the world have shown high rates of inappropriate prescribing. There is abundant circumstantial evidence linking emergence of

Victor Lim

2005-01-01

393

Antibiotics: When They Can and Can't Help  

MedlinePLUS

... and most coughs and sore throats. What is "antibiotic resistance?" “Antibiotic resistance” and “bacterial resistance” are two ways of describing the same thing. Usually, antibiotics kill bacteria or stop them from growing. However, ...

394

A multiplexed microfluidic platform for rapid antibiotic susceptibility testing  

E-print Network

A multiplexed microfluidic platform for rapid antibiotic susceptibility testing Ritika Mohan 1 March 2013 Accepted 25 April 2013 Available online 9 May 2013 Keywords: Antibiotic susceptibility screen patient samples to identify antibiograms of infecting pathogens. Existing methods for antibiotic

Kenis, Paul J. A.

395

21 CFR 333.110 - First aid antibiotic active ingredients.  

...2014-04-01 2014-04-01 false First aid antibiotic active ingredients. 333.110...PRODUCTS FOR OVER-THE-COUNTER HUMAN USE First Aid Antibiotic Drug Products § 333.110 First aid antibiotic active ingredients. The...

2014-04-01

396

21 CFR 333.110 - First aid antibiotic active ingredients.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false First aid antibiotic active ingredients. 333.110...PRODUCTS FOR OVER-THE-COUNTER HUMAN USE First Aid Antibiotic Drug Products § 333.110 First aid antibiotic active ingredients. The...

2011-04-01

397

21 CFR 333.110 - First aid antibiotic active ingredients.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false First aid antibiotic active ingredients. 333.110...PRODUCTS FOR OVER-THE-COUNTER HUMAN USE First Aid Antibiotic Drug Products § 333.110 First aid antibiotic active ingredients. The...

2010-04-01

398

21 CFR 333.110 - First aid antibiotic active ingredients.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false First aid antibiotic active ingredients. 333.110...PRODUCTS FOR OVER-THE-COUNTER HUMAN USE First Aid Antibiotic Drug Products § 333.110 First aid antibiotic active ingredients. The...

2013-04-01

399

21 CFR 333.110 - First aid antibiotic active ingredients.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false First aid antibiotic active ingredients. 333.110...PRODUCTS FOR OVER-THE-COUNTER HUMAN USE First Aid Antibiotic Drug Products § 333.110 First aid antibiotic active ingredients. The...

2012-04-01

400

REVIEW ARTICLE Occurrence, fate, and ecotoxicity of antibiotics  

E-print Network

, biosolids, and manures. More impor- tantly, significant amount of antibiotics and their bioactive with antibiotics-polluted manures, biosolids, sewage sludge, sediments, and water. Subsequently, accumulation animal manures and urban biosolids. . . . . . . . . . . . . . . .5 2.1.2 Antibiotic concentrations

Paris-Sud XI, Université de

401

Antibiotic use, resistance development and environmental factors: a qualitative study among healthcare professionals in Orissa, India  

PubMed Central

Background Antibiotic resistance is a major public health problem affecting both current and future generations. The influence of environmental factors on antibiotic use and resistance development in bacteria is largely unknown. This study explored the perceptions of healthcare providers on antibiotic use and resistance development in relation to environmental factors i.e. physical, natural, social and behavioural factors. Methods A qualitative interview study was conducted using face-to-face, semi-structured interviews among registered allopathic doctors, veterinarians and drug dispensers in Orissa, India. The interview transcripts were analyzed using latent content analysis. Results The main findings of this study relate to two themes: 'Interrelationship between antibiotic use, resistance development and environment' and 'Antibiotic management contributing to the development and spread of resistance'. The interviewees viewed the following as possible contributors to antibiotic use/misuse and resistance development: changes in the natural and physical environment i.e. climate variability, pollution, physiography and population growth; the socioeconomic environment affecting health-seeking behaviour and noncompliance with medication; a lack of healthcare facilities and poor professional attitudes; and ineffective law enforcement regarding medicine dispensing and disposal. Conclusions Generally, the interviewees perceived that although behavioural and social environmental factors are major contributors to resistance development, changes in the physical and natural environment also influence development of antibiotic resistance. The respondents also perceived that there is a lack of information about, and poor awareness of, what constitutes prudent use of antibiotics. They suggested a need for information, education, dissemination and proper implementation and enforcement of legislation at all levels of the drug delivery and disposal system in order to improve antibiotic use and prevent pharmaceutical contamination of the environment. PMID:20964815

2010-01-01

402

Comparison of two methods for collecting antibiotic use data on small dairy farms.  

PubMed

Antibiotics are commonly used in animal agriculture; they can improve animal health and productivity, but their use may also represent a public health threat. Very little is known about antibiotic use on small farms in lower/middle income countries. To understand antibiotic use on these farms and promote the judicious use of these drugs, pharmacoepidemiologic data are necessary. However, acquiring such data can be difficult, as farmers are often illiterate (and therefore cannot participate in written surveys or keep treatment records), antibiotics can be obtained over-the-counter (in which case no prescriptions are generated) and monitoring and surveillance systems for drug use are often non-existent. The goal of this study was to compare two methods of acquiring pharmacoepidemiologic data pertaining to antibiotics that are well-adapted to farms in lower-middle income countries: self-report and the collection of discarded drug packaging. A convenience sample of 20 farmers in Cajamarca, Peru, participated in the study. Farmers placed discarded antibiotic packaging in bins for six months. At the end of the six-month period, farmers were interviewed and asked to recall the antibiotic usage that occurred on their farm over the past month and past six months; these self-reported data were quantitatively and qualitatively compared to the bin contents collected in the last month and previous six months. We found that the agreement between the bins and self-report was relatively poor for both the quantity and types of antibiotics used. The bins appeared to perform better than self-report when bottles and mLs of antibiotics were measured, while self-report appeared to perform better for intra-mammary infusions. The bins also appeared to perform better when data pertaining to an extended time period (six months) were collected. The results of this study will provide guidance to investigators seeking to collect pharmacoepidemiologic data in similar environments. PMID:24630404

Redding, L E; Cubas-Delgado, F; Sammel, M D; Smith, G; Galligan, D T; Levy, M Z; Hennessy, S

2014-06-01

403

Evolution of Resistance to a Last-Resort Antibiotic in Staphylococcus aureus via Bacterial Competition.  

PubMed

Antibiotic resistance is a key medical concern, with antibiotic use likely being an important cause. However, here we describe an alternative route to clinically relevant antibiotic resistance that occurs solely due to competitive interactions among bacterial cells. We consistently observe that isolates of Methicillin-resistant Staphylococcus aureus diversify spontaneously into two distinct, sequentially arising strains. The first evolved strain outgrows the parent strain via secretion of surfactants and a toxic bacteriocin. The second is resistant to the bacteriocin. Importantly, this second strain is also resistant to intermediate levels of vancomycin. This so-called VISA (vancomycin-intermediate S. aureus) phenotype is seen in many hard-to-treat clinical isolates. This strain diversification also occurs during in vivo infection in a mouse model, which is consistent with the fact that both coevolved phenotypes resemble strains commonly found in clinic. Our study shows how competition between coevolving bacterial strains can generate antibiotic resistance and recapitulate key clinical phenotypes. PMID:25171407

Koch, Gudrun; Yepes, Ana; Förstner, Konrad U; Wermser, Charlotte; Stengel, Stephanie T; Modamio, Jennifer; Ohlsen, Knut; Foster, Kevin R; Lopez, Daniel

2014-08-28

404

Incorporation of different antibiotics into carbonated hydroxyapatite coatings on titanium implants, release and antibiotic efficacy.  

PubMed

Carbonated hydroxyapatite (CHA) coatings were applied onto titanium implants by using a biomimetic precipitation method. Different antibiotics were incorporated into the CHA coatings and their release and efficacy against bacteria growth were studied in vitro. The following antibiotics were used within this study: cephalothin, carbenicillin, amoxicillin, cefamandol, tobramycin, gentamicin and vancomycin. Increased concentrations of antibiotics in the coating solution led to a higher quantity of antibiotic incorporated into the CHA coating. Some antibiotics were better incorporated than others depending on their chemical structure. Antibiotics, containing carboxylic groups such as cephalothin, carbenicillin and cefamandol, were better incorporated than antibiotics lacking these groups. A bacterial inhibition test on Staphylococcus aureus bacteria showed inhibition of growth for all antibiotics that were released from the CHA coating. A release test was conducted in phosphate buffer saline PBS at pH 7.4 and 37 degrees C and showed that antibiotics containing carboxylic groups like cephalothin were slower released from the CHA coating than others. These results suggest that certain antibiotics are able to bind/chelate with calcium, resulting in a better incorporation into the CHA coating and a slower release. Antibiotics incorporated in CHA coatings on titanium implants might be used to prevent post-surgical infections and to promote bone-bonding of orthopedic devices. PMID:15342186

Stigter, M; Bezemer, J; de Groot, K; Layrolle, P

2004-09-14

405

[Failures of antibiotic treatment in Lyme arthritis].  

PubMed

Antibiotic treatment has been proven to be effective in about 90% of patients with Lyme arthritis in controlled studies. Overt arthritis persisting in spite of antibiotic therapy is rare and most likely has an autoimmune background. More frequently, patients with history of Lyme borreliosis present with non-specific articular and musculosceletal symptoms, which seem to be permanent sequelae of arthritis or constitute part of so called post-Lyme disease syndrome, of unclear pathogenesis. As persistence of active infection after proper antibiotic therapy is unlikely, repeated treatment seems of no benefit in most of the patients. No more than 2-3 attempts of antibiotic therapy should be undertaken; if symptoms persist, symptomatic and anti-inflammatory treatment should be introduced. Lack of response to antibiotics should also point to co-existing musculoskeletal morbidity or to improper diagnosis of Lyme borreliosis, which is frequent due to common occurrence of false-positive serologic tests results. PMID:19108522

Grygorczuk, Sambor; Zajkowska, Joanna; Kondrusik, Maciej; Moniuszko, Anna; Pancewicz, S?awomir; Pawlak-Zalewska, Wioletta

2008-01-01

406

Innovation of novel antibiotics: an economic perspective.  

PubMed

Despite the public attention to antibiotic overuse and the specter of antimicrobial-resistant pathogens, current infections necessitate the use of antibiotics. Yet, patients and providers may not fully consider the societal cost associated with inappropriate antimicrobial use and subsequent resistance. Policies intended to limit use to minimize resistance must be balanced with the competing concern of underutilization. It is difficult to determine whether research and development incentives or reducing the costs of bringing new antibiotics through expedited review will be sufficient. Likely, the most effective method would be allowing higher prices for use deemed to be clinically appropriate. The ultimate policy goal is to ensure that antibiotics are used appropriately, with the right patients receiving the right medication at the right time, and that the world has a steady stream of future antibiotics to effectively treat the resistant organisms that will inevitably emerge. PMID:25261536

McKellar, Michael R; Fendrick, A Mark

2014-10-15

407

Antibiotic overuse and resistance in dermatology.  

PubMed

Antibiotics have a significant role in dermatology, treating a wide range of diseases, including acne, rosacea, inflammatory skin conditions and skin structure infections, such as cellulitis, folliculitis, carbuncles, and furuncles. Because of their consistent use, utility, and availability, antibiotics are susceptible to overuse within the medical practice, and, specific to this discussion, in the dermatologic setting. The issue of continuously increasing risk of antibiotic resistance remains an important concern to the dermatologist. The scope of this review will be to provide an overview of the common antibiotics used in the dermatologic setting with an emphasis on identifying areas of overuse, reported bacterial resistance, and discussion of clinical management aimed at decreasing antibiotic resistance. PMID:22591499

Chon, Susan Y; Doan, Hung Q; Mays, Rana Majd; Singh, Selina M; Gordon, Rachel A; Tyring, Stephen K

2012-01-01

408

Tackling antibiotic resistance in India.  

PubMed

Infectious diseases are major causes of mortality in India. This is aggravated by the increasing prevalence of antimicrobial resistance (AMR) both in the community and in hospitals. Due to the emergence of resistance to all effective antibiotics in nosocomial pathogens, the situation calls for emergency measures to tackle AMR in India. India has huge challenges in tackling AMR, ranging from lack of surveillance mechanisms for monitoring AMR and use; effective hospital control policies; sanitation and non-human use of antimicrobial. The Ministry of Health and Family Welfare of Govt. of India has taken initiatives to tackle AMR. Extensive guidelines have been drafted and a model worksheet has been developed as a roadmap to tackle AMR. PMID:25353717

Wattal, Chand; Goel, Neeraj

2014-12-01

409

Antibiotics and antibiotic-resistant bacteria in waters associated with a hospital in Ujjain, India  

PubMed Central

Background Concerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies on antibiotic prescription quantity in a hospital and antibiotic residue levels and resistant bacteria in the effluent of the same hospital are few. Therefore, we quantified antibiotic residues in waters associated with a hospital in India and assessed their association, if any, with quantities of antibiotic prescribed in the hospital and the susceptibility of Escherichia coli found in the hospital effluent. Methods This cross-sectional study was conducted in a teaching hospital outside the city of Ujjain in India. Seven antibiotics - amoxicillin, ceftriaxone, amikacin, ofloxacin, ciprofloxacin, norfloxacin and levofloxacin - were selected. Prescribed quantities were obtained from hospital records. The samples of the hospital associated water were analysed for the above mentioned antibiotics using well developed and validated liquid chromatography/tandem mass spectrometry technique after selectively isolating the analytes from the matrix using solid phase extraction. Escherichia coli isolates from these waters were tested for antibiotic susceptibility, by standard Kirby Bauer disc diffusion method using Clinical and Laboratory Standard Institute breakpoints. Results Ciprofloxacin was the highest prescribed antibiotic in the hospital and its residue levels in the hospital wastewater were also the highest. In samples of the municipal water supply and the groundwater, no antibiotics were detected. There was a positive correlation between the quantity of antibiotics prescribed in the hospital and antibiotic residue levels in the hospital wastewater. Wastewater samples collected in the afternoon contained both a higher number and higher levels of antibiotics compared to samples collected in the morning hours. No amikacin was found in the wastewater, but E.coli isolates from all wastewater samples were resistant to amikacin. Although ciprofloxacin was the most prevalent antibiotic detected in the wastewater, E.coli was not resistant to it. Conclusions Antibiotics are entering the aquatic environment of countries like India through hospital effluent. In-depth studies are needed to establish the correlation, if any, between the quantities of antibiotics prescribed in hospitals and the levels of antibiotic residues found in hospital effluent. Further, the effect of this on the development of bacterial resistance in the environment and its subsequent public health impact need thorough assessment. PMID:20626873

2010-01-01

410

Salmonella typhimurium intercepts Escherichia coli signaling to enhance antibiotic tolerance  

E-print Network

Salmonella typhimurium intercepts Escherichia coli signaling to enhance antibiotic tolerance Nicole Salmonella typhimurium increases its antibiotic toler- ance in response to indole, even though S. typhimurium

Collins, James J.

411

In vitro activity of DU-6681a, an active form of the new oral carbapenem compound DZ-2640, in comparison with that of R-95867, faropenem and oral cephalosporins.  

PubMed

We compared the in vitro antibacterial activity of DU-6681a against Gram-positive and Gram-negative bacteria with that of R-95867, faropenem and oral cephalosporins such as cefcapene, cefotiam and cefpodoxime. DU-6681a is an active form of the new oral carbapenem compound DZ-2640, which is an ester-type prodrug, and R-95867 is an active form of the oral carbapenem CS-834. Against most Gram-positive bacteria, DU-6681a was as active as or two- to 16-fold more potent than R-95867 and faropenem in terms of MIC(90), and comparable to or two- to 64-fold more effective than the cephalosporins. Against most Gram-negative bacteria, the activity of DU-6681a was the same as or two- to 16-fold more potent than that of R-95867, and comparable to or two- to 2048-fold higher than that of faropenem and the cephalosporins. PMID:10882697

Okuda, J; Otsuki, M; Oh, T; Nishino, T

2000-07-01

412

"Practical knowledge" and perceptions of antibiotics and antibiotic resistance among drugsellers in Tanzanian private drugstores  

PubMed Central

Background Studies indicate that antibiotics are sold against regulation and without prescription in private drugstores in rural Tanzania. The objective of the study was to explore and describe antibiotics sale and dispensing practices and link it to drugseller knowledge and perceptions of antibiotics and antibiotic resistance. Methods Exit customers of private drugstores in eight districts were interviewed about the drugstore encounter and drugs bought. Drugsellers filled in a questionnaire with closed- and open-ended questions about antibiotics and resistance. Data were analyzed using mixed quantitative and qualitative methods. Results Of 350 interviewed exit customers, 24% had bought antibiotics. Thirty percent had seen a health worker before coming and almost all of these had a prescription. Antibiotics were dispensed mainly for cough, stomachache, genital complaints and diarrhea but not for malaria or headache. Dispensed drugs were assessed as relevant for the symptoms or disease presented in 83% of all cases and 51% for antibiotics specifically. Non-prescribed drugs were assessed as more relevant than the prescribed. The knowledge level of the drugseller was ranked as high or very high by 75% of the respondents. Seventy-five drugsellers from three districts participated. Seventy-nine percent stated that diseases caused by bacteria can be treated with antibiotics but 24% of these also said that antibiotics can be used for treating viral disease. Most (85%) said that STI can be treated with antibiotics while 1% said the same about headache, 4% general weakness and 3% 'all diseases'. Seventy-two percent had heard of antibiotic resistance. When describing what an antibiotic is, the respondents used six different kinds of keywords. Descriptions of what antibiotic resistance is and how it occurs were quite rational from a biomedical point of view with some exceptions. They gave rise to five categories and one theme: Perceiving antibiotic resistance based on practical experience. Conclusions The drugsellers have considerable "practical knowledge" of antibiotics and a perception of antibiotic resistance based on practical experience. In the process of upgrading private drugstores and formalizing the sale of antibiotics from these outlets in resource-constrained settings, their "practical knowledge" as well as their perceptions must be taken into account in order to attain rational dispensing practices. PMID:20846407

2010-01-01

413

Effects of antibiotic treatment of nonlactating dairy cows on antibiotic resistance patterns of bovine mastitis pathogens.  

PubMed Central

Antibiotic resistance patterns of the major groups of bovine mastitis pathogens (Streptococcus agalactiae, other streptococci, Staphylococcus aureus, and Staphylococcus epidermidis) were examined by determining the minimum inhibitory concentration (MIC) of 13 different antibiotics against bacterial isolates from dairy cattle. The bacterial strains were obtained from milk samples from each cow in 21 New York state dairy herd surveys. In 12 herd surveys (high antibiotic-use group), all 365 cows received antibiotic infusions into the udder at the cessation of each lactation cycle. The 324 animals in the other nine herd surveys (low antibiotic-use group) did not routinely receive antibiotics during the nonlactation period. The MICs from the two groups were compared by calculating for each bacterial group the average MIC, the antibiotic concentration necessary to inhibit 90% of the isolates, and the antibiotic concentration necessary to inhibit 50% of the isolates. Increased resistance to all 13 antibiotics was observed with Streptococcus agalactiae isolates from the high antibiotic use herds. However, there was relatively little difference between the two groups in the resistance patterns of the other bacterial species examined. The most important finding of the study was the identification of a multiple beta-lactam resistance phenotype in Streptococcus agalactiae. PMID:6660851

Berghash, S R; Davidson, J N; Armstrong, J C; Dunny, G M

1983-01-01

414

Biological counterstrike: antibiotic resistance mechanisms of Gram-positive cocci.  

PubMed

The development of antibiotic resistance by bacteria is an evolutionary inevitability, a convincing demonstration of their ability to adapt to adverse environmental conditions. Since the emergence of penicillinase-producing Staphylococcus aureus in the 1940s, staphylococci, enterococci and streptococci have proved themselves adept at developing or acquiring mechanisms that confer resistance to all clinically available antibacterial classes. The increasing problems of methicillin-resistant S. aureus and coagulase-negative staphylococci (MRSA and MRCoNS), glycopeptide-resistant enterococci and penicillin-resistant pneumococci in the 1980s, and recognition of glycopeptide-intermediate S. aureus in the 1990s and, most recently, of fully vancomycin-resistant isolates of S. aureus have emphasised our need for new anti-Gram-positive agents. Antibiotic resistance is one of the major public health concerns for the beginning of the 21st century. The pharmaceutical industry has responded with the development of oxazolidinones, lipopeptides, injectable streptogramins, ketolides, glycylcyclines, second-generation glycopeptides and novel fluoroquinolones. However, clinical use of these novel agents will cause new selective pressures and will continue to drive the development of resistance. This review describes the various antibiotic resistance mechanisms identified in isolates of staphylococci, enterococci and streptococci, including mechanisms of resistance to recently introduced anti-Gram-positive agents. PMID:15811020

Woodford, N

2005-05-01

415

MICROBIOLOGY: Signaling Antibiotic Resistance in Staphylococci  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required: For 30 years biologists have studied the molecular machinery of staphylococcal bacteria that renders them resistant to b-lactam antibiotics. In a Perspective, Archer and Bosilevac discuss new findings showing that cleavage of a sensor-transducer protein after it binds to a b-lactam antibiotic results in cleavage of the repressor protein that binds to the blaZ gene. b-Lactamase is then produced and binds to and inactivates the antibiotic.

Gordon L. Archer (Medical College of Virginia/Commonwealth University;Departments of Medicine and Microbiology/Immunology); Joseph M. Bosilevac (Medical College of Virginia/Commonwealth University;Departments of Medicine and Microbiology/Immunology)

2001-03-09

416

Perioperative antibiotic prophylaxis: the importance of timing.  

PubMed

1. Although prophylactic antibiotics have demonstrated efficacy in surgical procedures, they can fail because, generally, an inappropriate agent is used or the agent is inappropriately administered. 2. The timing of administration is important. Studies indicate that to reduce the risk of infection, high levels of antibiotic must be present in the bloodstream and tissues at the time of the incision. 3. Nurses play a central role in ensuring the proper timing of the administration of prophylactic antibiotics. Improvement in the timing of administration will reduce both morbidity and institutional costs. PMID:1412627

Bryant, J; Pfaff, S

1992-10-01

417

How Nature Morphs Peptide Scaffolds into Antibiotics  

PubMed Central

The conventional notion that peptides are poor candidates for orally available drugs because of protease-sensitive peptide bonds, intrinsic hydrophilicity, and ionic charges contrasts with the diversity of antibiotic natural products with peptide-based frameworks that are synthesized and utilized by Nature. Several of these antibiotics, including penicillin and vancomycin, are employed to treat bacterial infections in humans and have been best-selling therapeutics for decades. Others might provide new platforms for the design of novel therapeutics to combat emerging antibiotic-resistant bacterial pathogens. PMID:19058272

Nolan, Elizabeth M.; Walsh, Christopher T.

2010-01-01

418

Non-prescription antibiotic use in Hungary  

Microsoft Academic Search

Objective  To estimate the extent, prevalence, and trends in non-prescription antibiotic use in Hungary between 2000 and 2004 at national\\u000a and regional levels. To identify determinants of nonprescription antibiotic use.\\u000a \\u000a \\u000a \\u000a Method  Data on non-prescription sales of systemic antibiotics (Anatomical Therapeutic Chemical (ATC) class J01) were analyzed over\\u000a a five-year period. The 2004 version of the World Health Organisation ATC\\/defined daily dose (DDD)

Maria Matuz; Ria Benko; Peter Doro; Gyongyver Soos

2007-01-01

419

Amino Acid Substitutions at Ambler Position Gly238 in the SHV-1 ?-Lactamase: Exploring Sequence Requirements for Resistance to Penicillins and Cephalosporins  

PubMed Central

Site saturation mutagenesis of the 238 position in the SHV ?-lactamase was performed to identify the complete sequence requirements needed for the extended spectrum ?-lactamase (ESBL) phenotype. MICs (in micrograms per milliliter) in an isogenic background, Escherichia coli DH10B, demonstrated that the Gly238Ala mutation conferred the most resistance to penicillins and cephalosporins. The absolute increase in resistance was greatest against cefotaxime for the Gly238Ala mutant (0.06 to 8 ?g/ml). Except for the strain possessing the Gly238Pro ?-lactamase, ceftazidime MICs were also elevated. None of the mutant SHV ?-lactamases were expressed in as great an amount as the wild-type ?-lactamase. Kinetic analysis of the Gly238Ala mutant revealed that penicillin and cephalosporin substrates have a lower Km for the enzyme because of this mutation. Ampicillin and piperacillin MICs were inversely proportional to the side chain volume of the amino acid in cases larger than Ser, suggesting that steric considerations may be a primary requirement for penicillin resistance. Secondary structural effects explain increased resistance to oxyiminocephalosporins. Based upon this study, we anticipate that additional mutations of Gly238 in the SHV ?-lactamase will continue to be discovered with an ESBL (ceftazidime or cefotaxime resistant) phenotype. PMID:12435703

Hujer, Andrea M.; Hujer, Kristine M.; Helfand, Marion S.; Anderson, Vernon E.; Bonomo, Robert A.

2002-01-01

420

Antibiotic resistance in Enterococcus faecium clinical isolates.  

PubMed

The worldwide ratio of Enterococcus faecalis-Enterococcus faecium infections is currently changing in favor of E. faecium. Intrinsic and acquired antimicrobial resistance traits of this latter species can explain this evolution as well as the diffusion of hospital-adapted strains belonging to the clonal complex CC17. Like other enterococci, E. faecium is naturally resistant to cephalosporins and aminoglycosides (at low level). Because of its high genome plasticity, it can also acquire numerous other resistances. It is noteworthy that most modern isolates of E. faecium are highly resistant to ampicillin while a non-negligible proportion of them (depending on geographical locations) are resistant to glycopeptides (especially in the USA). Even if resistance to newer antimicrobial agents (linezolid, daptomycin, tigecycline) is still uncommon, some clinical isolates with reduced susceptibility or resistance have already been reported and better understanding of resistance mechanisms is needed for prediction and prevention of their dissemination. PMID:24392717

Cattoir, Vincent; Giard, Jean-Christophe

2014-02-01

421

Analytical Method for Streptothricin-Type Antibiotics: Structure of Antibiotic LL-BL1361  

PubMed Central

An analytical procedure was devised which can distinguish members of the streptothricin family of antibiotics. It is based upon an analysis of the hydrolysis products of the antibiotics using a Technicon amino acid autoanalyzer under special conditions. The various fragments including the different streptolidine-amino sugar compounds were well resolved. A basic water-soluble antibiotic discovered in our laboratories and named LL-BL136 was compared to other members of this group by this technique. It was not differentiated from the antibiotic SF-701 reported by Tsuruoka. The autoanalyzer results along with other physicochemical data permitted a structure proposal for this antibiotic, which is the N-methyl-desformimino derivative of antibiotic LL-AC541. PMID:4670481

Borders, D. B.; Kirby, J. P.; Wetzel, E. R.; Davies, M. C.; Hausmann, W. K.

1972-01-01

422

Something old, something new: revisiting natural products in antibiotic drug discovery.  

PubMed

Antibiotic discovery is in crisis. Despite a growing need for new drugs resulting from the increasing number of multi-antibiotic-resistant pathogens, there have been only a handful of new antibiotics approved for clinical use in the past 2 decades. Faced with scientific, economic, and regulatory challenges, the pharmaceutical sector seems unable to respond to what has been called an "apocalyptic" threat. Natural products produced by bacteria and fungi are genetically encoded products of natural selection that have been the mainstay sources of the antibiotics in current clinical use. The pharmaceutical industry has largely abandoned these compounds in favor of large libraries of synthetic molecules because of difficulties in identifying new natural product antibiotics scaffolds. Advances in next-generation genome sequencing, bioinformatics, and analytical chemistry are combining to overcome barriers to natural products. Coupled with new strategies in antibiotic discovery, including inhibition of resistance, novel drug combinations, and new targets, natural products are poised for a renaissance to address what is a pressing health care crisis. PMID:24588388

Wright, Gerard D

2014-03-01

423

Chronological change of antibiotic use and antibiotic resistance in Escherichia coli causing urinary tract infections  

Microsoft Academic Search

Overuse of antibiotics can cause the emergence of resistant bacterial strains. This study retrospectively investigated recent\\u000a trends in Escherichia coli causing urinary tract infections (UTIs), focusing on antibiotic use and antibiotic susceptibilities. Patients diagnosed with\\u000a UTIs caused by E. coli in Akashi Municipal Hospital between April 2004 and March 2010 were enrolled in the study. A total of 858 UTI

Katsumi Shigemura; Kazushi Tanaka; Masayo Adachi; Masuo Yamashita; Soichi Arakawa; Masato Fujisawa

424

Antibiotic Use in Children Leveling Off  

MedlinePLUS

... Fitness Nutrition Puberty School Teen: 12-18 yrs. Dating & Sex Fitness Nutrition Safety School Substance Abuse Young ... Trends in Outpatient Antibiotic Use in Children ,” (published online Feb. 3) study authors reviewed pharmacy and outpatient ...

425

A Strategy for Fighting Antibiotic Resistance  

NSDL National Science Digital Library

The American Society for Microbiology posted this recent paper online, addressing the critical issue of how to fight antibiotic resistance. Several strategies to slow the development of resistance are presented.

Lica, Karl.

2000-01-01

426

Dental implant installation without antibiotic prophylaxis.  

PubMed

The objective of this study was to retrospectively compare the outcomes of dental implant treatment with and without antibiotic prophylaxis. Two groups of patients with edentulous or partially edentulous maxillas or mandibles (or both) were treated with dental implants. One group, consisting of 147 patients (790 implants), was given prophylaxis with oral phenoxymethylpenicillin; 1 g of antibiotic was administered 1 hour preoperatively, and 1 g was administered every 8 hours for 10 days postoperatively. The other group, consisting of 132 patients (664 implants) was not given any antibiotics preoperatively or postoperatively. There were no significant differences with respect to early and late postoperative infections or with respect to implant survival between the two groups. It appears that antibiotic prophylaxis for routine dental implant surgery offers no advantage for the patient. PMID:9619664

Gynther, G W; Köndell, P A; Moberg, L E; Heimdahl, A

1998-05-01

427

Mechanisms of antibiotic resistance in enterococci.  

PubMed

Multidrug-resistant (MDR) enterococci are important nosocomial pathogens and a growing clinical challenge. These organisms have developed resistance to virtually all antimicrobials currently used in clinical practice using a diverse number of genetic strategies. Due to this ability to recruit antibiotic resistance determinants, MDR enterococci display a wide repertoire of antibiotic resistance mechanisms including modification of drug targets, inactivation of therapeutic agents, overexpression of efflux pumps and a sophisticated cell envelope adaptive response that promotes survival in the human host and the nosocomial environment. MDR enterococci are well adapted to survive in the gastrointestinal tract and can become the dominant flora under antibiotic pressure, predisposing the severely ill and immunocompromised patient to invasive infections. A thorough understanding of the mechanisms underlying antibiotic resistance in enterococci is the first step for devising strategies to control the spread of these organisms and potentially establish novel therapeutic approaches. PMID:25199988

Miller, William R; Munita, Jose M; Arias, Cesar A

2014-10-01

428

Supplementary Information Reactions of Tetracycline Antibiotics  

E-print Network

1 Supplementary Information Reactions of Tetracycline Antibiotics with Chlorine Dioxide and Free such as pharmaceuticals that contain a UV-active chromophore close enough to the site of the acid­base function

Huang, Ching-Hua

429

Antibiotics DOI: 10.1002/anie.200801801  

E-print Network

that has over- come every antibiotic cam- paign. Methicillin-resistant S. aureus (MRSA) infections proceeds through the same early steps as sterol biosynthesis. A recent anti- MRSA drug-discovery effort

Nizet, Victor

430

Steroids/Nutritional Supplements/Antibiotics  

MedlinePLUS

Steroids/Nutritional Supplements/Antibiotics There are multiple steroid/supplemental treatments for Duchenne although there is little agreement ( ... Deflazacort Albuterol Creatine Anabolic Steroids Calcium blockers Gentamycin Prednisone This is a catabolic steroid that slows the ...