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Antimicrobial Agents and Chemotherapy Dec 2009A Swedish patient of Indian origin traveled to New Delhi, India, and acquired a urinary tract infection caused by a carbapenem-resistant Klebsiella pneumoniae strain...
Characterization of a new metallo-beta-lactamase gene, bla(NDM-1), and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumoniae sequence type 14 from India.
A Swedish patient of Indian origin traveled to New Delhi, India, and acquired a urinary tract infection caused by a carbapenem-resistant Klebsiella pneumoniae strain that typed to the sequence type 14 complex. The isolate, Klebsiella pneumoniae 05-506, was shown to possess a metallo-beta-lactamase (MBL) but was negative for previously known MBL genes. Gene libraries and amplification of class 1 integrons revealed three resistance-conferring regions; the first contained bla(CMY-4) flanked by ISEcP1 and blc. The second region of 4.8 kb contained a complex class 1 integron with the gene cassettes arr-2, a new erythromycin esterase gene; ereC; aadA1; and cmlA7. An intact ISCR1 element was shown to be downstream from the qac/sul genes. The third region consisted of a new MBL gene, designated bla(NDM-1), flanked on one side by K. pneumoniae DNA and a truncated IS26 element on its other side. The last two regions lie adjacent to one another, and all three regions are found on a 180-kb region that is easily transferable to recipient strains and that confers resistance to all antibiotics except fluoroquinolones and colistin. NDM-1 shares very little identity with other MBLs, with the most similar MBLs being VIM-1/VIM-2, with which it has only 32.4% identity. As well as possessing unique residues near the active site, NDM-1 also has an additional insert between positions 162 and 166 not present in other MBLs. NDM-1 has a molecular mass of 28 kDa, is monomeric, and can hydrolyze all beta-lactams except aztreonam. Compared to VIM-2, NDM-1 displays tighter binding to most cephalosporins, in particular, cefuroxime, cefotaxime, and cephalothin (cefalotin), and also to the penicillins. NDM-1 does not bind to the carbapenems as tightly as IMP-1 or VIM-2 and turns over the carbapenems at a rate similar to that of VIM-2. In addition to K. pneumoniae 05-506, bla(NDM-1) was found on a 140-kb plasmid in an Escherichia coli strain isolated from the patient's feces, inferring the possibility of in vivo conjugation. The broad resistance carried on these plasmids is a further worrying development for India, which already has high levels of antibiotic resistance.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Carboxylic Ester Hydrolases; Cefotaxime; Cefuroxime; Cephalosporins; Cephalothin; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Humans; India; Kinetics; Klebsiella Infections; Klebsiella pneumoniae; Microbial Sensitivity Tests; Molecular Sequence Data; Penicillins; Sequence Analysis, DNA; Sequence Homology, Amino Acid; beta-Lactamases
PubMed: 19770275
DOI: 10.1128/AAC.00774-09 -
Equine Veterinary Journal Nov 2021First-generation cephalosporins have good activity against gram-positive bacteria and are extensively used in horses. There are few reports of pharmacokinetics and...
BACKGROUND
First-generation cephalosporins have good activity against gram-positive bacteria and are extensively used in horses. There are few reports of pharmacokinetics and pharmacodynamics (PK/PD) analysis of cephalosporins in horses.
OBJECTIVE
To optimise the dosages of the two first-generation cephalosporins cephalothin (CET) and cefazolin (CEZ) in horses using PK/PD concepts.
STUDY DESIGN
Experimental study with single administration.
METHODS
Drug plasma concentrations following a single intravenous (i.v.) administration of 22 mg/kg bodyweight (bwt) CET in 12 horses and of 10 mg/kg bwt CEZ in six horses were measured using LC-MS/MS. Data were modelled using a nonlinear mixed effect modelling followed by Monte Carlo simulations. Minimum inhibitory concentrations (MICs) against Streptococcus zooepidemicus and Staphylococcus aureus isolated from horses were determined by the microbroth dilution method.
RESULTS
The percentages of CET and CEZ binding to serum proteins were 19.9% ± 8.4% and 15.2% ± 8.5% respectively. For both CET and CEZ, the MIC against S. zooepidemicus was 0.12 mg/L and against S. aureus was 0.5 mg/L. For CET, to achieve a probability of target attainment (PTA) of 90% for a PK/PD target of a free serum plasma concentration exceeding the MIC for 40% of the dosing interval, an empirical CET dosage regimen of 22 mg/kg bwt q8h and 22 mg/kg bwt q4h i.v. administration were required for S. zooepidemicus and S. aureus respectively. For CEZ, the corresponding dosage regimens were 10 mg/kg bwt q12h and 10 mg/kg bwt q8h.
MAIN LIMITATIONS
Small sample size only in healthy horses.
CONCLUSIONS
For CET, more frequent administration than that currently recommended (22 mg/kg bwt q6-12h) is required to empirically control S. aureus infection in horses. For CEZ, less frequent administration compared to the dosage regimen currently proposed (10-22 mg/kg bwt q6h) could control S. zooepidemicus and S. aureus infections in horses.
Topics: Animals; Anti-Bacterial Agents; Cefazolin; Cephalothin; Chromatography, Liquid; Horses; Microbial Sensitivity Tests; Staphylococcus aureus; Tandem Mass Spectrometry
PubMed: 33341979
DOI: 10.1111/evj.13406 -
Journal of Applied Microbiology Aug 2022To investigate the priming effects of sub-inhibitory concentrations of biocides on antibiotic resistance in bacteria.
AIMS
To investigate the priming effects of sub-inhibitory concentrations of biocides on antibiotic resistance in bacteria.
METHODS AND RESULTS
Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were exposed to sub-inhibitory concentrations of biocides via a gradient plate method. Minimum inhibitory concentration (MIC) and antibiotic susceptibility were determined, and efflux pump inhibitors (thioridazine and chlorpromazine) were used to investigate antibiotic resistance mechanism(s). Escherichia coli displayed a twofold increase in MIC (32-64 mg l ) to H O which was stable after 15 passages, but lost after 6 weeks, and P. aeruginosa displayed a twofold increase in MIC (64-128 mg l ) to BZK which was also stable for 15 passages. There were no other tolerances observed to biocides in E. coli, P. aeruginosa or S. aureus; however, stable cross-resistance to antibiotics was observed in the absence of a stable increased tolerance to biocides. Sixfold increases in MIC to cephalothin and fourfold to ceftriaxone and ampicillin were observed in hydrogen peroxide primed E. coli. Chlorhexidine primed S. aureus showed a fourfold increase in MIC to oxacillin, and glutaraldehyde-primed P. aeruginosa showed fourfold (sulphatriad) and eightfold (ciprofloxacin) increases in MIC. Thioridazine increased the susceptibility of E. coli to cephalothin and cefoxitin by fourfold and twofold, respectively, and both thioridazine and chlorpromazine increased the susceptibility S. aureus to oxacillin by eightfold and fourfold, respectively.
CONCLUSIONS
These findings demonstrate that sub-inhibitory concentrations of biocides can prime bacteria to become resistant to antibiotics even in the absence of stable biocide tolerance and suggests activation of efflux mechanisms may be a contributory factor.
SIGNIFICANCE AND IMPACT OF THE STUDY
This study demonstrates the effects of low-level exposure of biocides (priming) on antibiotic resistance even in the absence of obvious increased biocidal tolerance.
Topics: Anti-Bacterial Agents; Cephalothin; Chlorpromazine; Disinfectants; Drug Resistance, Bacterial; Escherichia coli; Microbial Sensitivity Tests; Oxacillin; Pseudomonas aeruginosa; Staphylococcus aureus; Thioridazine
PubMed: 35384175
DOI: 10.1111/jam.15564 -
Journal of Clinical Microbiology Apr 2024Traditionally, cephalothin susceptibility results were used to predict the susceptibility of additional cephalosporins; however, in 2013-2014, the Clinical and... (Review)
Review
Traditionally, cephalothin susceptibility results were used to predict the susceptibility of additional cephalosporins; however, in 2013-2014, the Clinical and Laboratory Standards Institute (CLSI) revisited this practice and determined that cefazolin is a more accurate proxy than cephalothin for uncomplicated urinary tract infections (uUTIs). Therefore, a cefazolin surrogacy breakpoint was established to predict the susceptibility of seven oral cephalosporins for , , and in the context of uUTIs. Clinical microbiology laboratories face several operational challenges when implementing the cefazolin surrogacy breakpoint, which may lead to confusion for the best path forward. Here, we review the historical context and data behind the surrogacy breakpoints, review PK/PD profiles for oral cephalosporins, discuss challenges in deploying the breakpoint, and highlight the limited clinical outcome data in this space.
Topics: Humans; Cefazolin; Cephalosporins; Cephalothin; Anti-Bacterial Agents; Microbial Sensitivity Tests; Urinary Tract Infections; Escherichia coli; Monobactams
PubMed: 38457194
DOI: 10.1128/jcm.00788-21 -
Antimicrobial Agents and Chemotherapy Jan 19727-[alpha-(1-Methyl-4-pyridiniothio)-acetamido] cephalosporanic acid, referred to herein as BL-S 217, is a new broad-spectrum semisynthetic cephalosporin that offers... (Comparative Study)
Comparative Study
7-[alpha-(1-Methyl-4-pyridiniothio)-acetamido] cephalosporanic acid, referred to herein as BL-S 217, is a new broad-spectrum semisynthetic cephalosporin that offers several advantages over cephalothin. A comparison of the activity in vitro of these antibiotics indicates that BL-S 217 is about eightfold more effective against Streptococcus pyogenes and Diplococcus pneumoniae. Against gram-negative bacteria, BL-S 217 possesses a broader antibacterial spectrum than cephalothin, particularly against members of the Enterobacteriaceae family; e.g., BL-S 217 inhibited over 20% more strains of both Escherichia coli and Klebsiella than cephalothin and also showed some advantage in tests against Salmonella and Enterobacter. Overall, of 208 strains of Enterobacteriaceae tested, 172 were susceptible to BL-S 217 compared to 149 for cephalothin. BL-S 217 was less bound to human serum proteins than cephalothin and gave higher peak blood levels in mice after intramuscular administration. The LD(50) of BL-S 217 in mice after subcutaneous administration was in excess of 4,000 mg/kg. When administered by the same route to mice experimentally infected with cephalothin-sensitive bacterial strains, this new cephalosporin was 20 times more effective than cephalothin in S. pyogenes and D. pneumoniae infections and 3 to 4 times more efficacious in an E. coli infection. Its therapeutic efficacy was comparable to that of cephalothin in infections produced by strains of Staphylococcus aureus, Klebsiella pneumoniae, and Proteus mirabilis.
Topics: Acetamides; Animals; Bacteria; Bacterial Infections; Cephalosporins; Cephalothin; Drug Stability; Humans; Lethal Dose 50; Male; Mice; Microbial Sensitivity Tests; Pyridines
PubMed: 4670430
DOI: 10.1128/AAC.1.1.67 -
The Cochrane Database of Systematic... Jul 2016A septic abortion refers to any abortion (spontaneous or induced) complicated by upper genital tract infection including endometritis or parametritis. The mainstay of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
A septic abortion refers to any abortion (spontaneous or induced) complicated by upper genital tract infection including endometritis or parametritis. The mainstay of treatment of septic abortion is antibiotic therapy alone or in combination with evacuation of retained products of conception. Regimens including broad-spectrum antibiotics are routinely recommended for treatment. However, there is no consensus on the most effective antibiotics alone or in combination to treat septic abortion. This review aimed to bridge this gap in knowledge to inform policy and practice.
OBJECTIVES
To review the effectiveness of various individual antibiotics or antibiotic regimens in the treatment of septic abortion.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, and POPLINE using the following keywords: 'Abortion', 'septic abortion', 'Antibiotics', 'Infected abortion', 'postabortion infection'. We also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov for ongoing trials on 19 April, 2016.
SELECTION CRITERIA
We considered for inclusion randomised controlled trials (RCTs) and non-RCTs that compared antibiotic(s) to another antibiotic(s), irrespective of route of administration, dosage, and duration as well as studies comparing antibiotics alone with antibiotics in combination with other interventions such as dilation and curettage (D&C).
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data from included trials. We resolved disagreements through consultation with a third author. One review author entered extracted data into Review Manager 5.3, and a second review author cross-checked the entry for accuracy.
MAIN RESULTS
We included 3 small RCTs involving 233 women that were conducted over 3 decades ago.Clindamycin did not differ significantly from penicillin plus chloramphenicol in reducing fever in all women (mean difference (MD) -12.30, 95% confidence interval (CI) -25.12 to 0.52; women = 77; studies = 1). The evidence for this was of moderate quality. "Response to treatment was evaluated by the patient's 'fever index' expressed in degree-hour and defined as the total quantity of fever under the daily temperature curve with 99°F (37.2°C) as the baseline".There was no difference in duration of hospitalisation between clindamycin and penicillin plus chloramphenicol. The mean duration of hospital stay for women in each group was 5 days (MD 0.00, 95% CI -0.54 to 0.54; women = 77; studies = 1).One study evaluated the effect of penicillin plus chloramphenicol versus cephalothin plus kanamycin before and after D&C. Response to therapy was evaluated by "the time from start of antibiotics until fever lysis and time from D&C until patients become afebrile". Low-quality evidence suggested that the effect of penicillin plus chloramphenicol on fever did not differ from that of cephalothin plus kanamycin (MD -2.30, 95% CI -17.31 to 12.71; women = 56; studies = 1). There was no significant difference between penicillin plus chloramphenicol versus cephalothin plus kanamycin when D&C was performed during antibiotic therapy (MD -1.00, 95% CI -13.84 to 11.84; women = 56; studies = 1). The quality of evidence was low.A study with unclear risk of bias showed that the time for fever resolution (MD -5.03, 95% CI -5.77 to -4.29; women = 100; studies = 1) as well as time for resolution of leukocytosis (MD -4.88, 95% CI -5.98 to -3.78; women = 100; studies = 1) was significantly lower with tetracycline plus enzymes compared with intravenous penicillin G.Treatment failure and adverse events occurred infrequently, and the difference between groups was not statistically significant.
AUTHORS' CONCLUSIONS
We found no strong evidence that intravenous clindamycin alone was better than penicillin plus chloramphenicol for treating women with septic abortion. Similarly, available evidence did not suggest that penicillin plus chloramphenicol was better than cephalothin plus kanamycin for the treatment of women with septic abortion. Tetracyline enzyme antibiotic appeared to be more effective than intravenous penicillin G in reducing the time to fever defervescence, but this evidence was provided by only one study at low risk of bias.There is a need for high-quality RCTs providing reliable evidence for treatments of septic abortion with antibiotics that are currently in use. The three included studies were carried out over 30 years ago. There is also a need to include institutions in low-resource settings, such as sub-Saharan Africa, Latin America and the Caribbean, and South Asia, with a high burden of abortion and health systems challenges.
Topics: Abortion, Septic; Adult; Anti-Bacterial Agents; Cephalothin; Chloramphenicol; Clindamycin; Drug Therapy, Combination; Female; Humans; Kanamycin; Length of Stay; Penicillins; Pregnancy; Randomized Controlled Trials as Topic; Tetracycline
PubMed: 27364644
DOI: 10.1002/14651858.CD011528.pub2 -
Canadian Medical Association Journal Jul 1971
Topics: Cephaloridine; Cephalosporins; Cephalothin; Drug Hypersensitivity; Humans; Infections; Injections, Intramuscular; Injections, Intravenous; Kidney; Kidney Diseases; Thrombophlebitis
PubMed: 5092516
DOI: No ID Found -
Microbiology Spectrum Aug 2022Cephalexin and cefadroxil are oral first-generation cephalosporins used to treat methicillin-susceptible Staphylococcus aureus (MSSA) infections. Despite its shorter...
Cefadroxil Comparable to Cephalexin: Minimum Inhibitory Concentrations among Methicillin-Susceptible Staphylococcus aureus Isolates from Pediatric Musculoskeletal Infections.
Cephalexin and cefadroxil are oral first-generation cephalosporins used to treat methicillin-susceptible Staphylococcus aureus (MSSA) infections. Despite its shorter half-life, cephalexin is more frequently prescribed, although cefadroxil is an appealing alternative, given its slower clearance and possibility for less frequent dosing. We report comparative MIC distributions for cefadroxil and cephalexin, as well as for oxacillin, cephalothin, ceftaroline, and cefazolin, for 48 unique clinical MSSA isolates from pediatric patients with musculoskeletal infections. Both cefadroxil and cephalexin had MIC values of 2 μg/mL and MIC values of 4 μg/mL. MICs for oxacillin, cephalothin, and ceftaroline were ≤0.25 μg/mL, and cefazolin's MIC was 0.5 μg/mL. While cefadroxil and cephalexin MICs are higher than those for other active agents, the distributions of MICs for cefadroxil and cephalexin are statistically equivalent, suggesting similar MSSA activities. Cefadroxil should be further considered an alternative agent to cephalexin, although additional work is needed to identify the optimal dose and frequency of these antibiotics for the treatment of serious MSSA infections. Cephalexin and cefadroxil are oral antibiotics that are used to treat serious infections due to the bacteria MSSA. While cephalexin is used more commonly, cefadroxil is excreted from the body more slowly; this generally allows patients to take cefadroxil less frequently than cephalexin. In this study, we compared the abilities of cefadroxil, cephalexin, and several other representative intravenous antibiotics to inhibit the growth of MSSA in the laboratory. Bacterial samples were obtained from children with bone, joint, and/or muscle infections caused by MSSA. We found that cefadroxil and cephalexin inhibited the growth of MSSA at similar concentrations, suggesting similar antibacterial potencies. The selected intravenous antistaphylococcal antibiotics generally inhibited bacterial growth with lower antibiotic concentrations. Based on these results, cefadroxil should be further considered an alternative oral antibiotic to cephalexin, although future research is needed to identify the optimal dose and frequency of these antibiotics for serious infections.
Topics: Anti-Bacterial Agents; Bacteria; Cefadroxil; Cefazolin; Cephalexin; Cephalothin; Child; Humans; Methicillin; Microbial Sensitivity Tests; Oxacillin; Staphylococcal Infections; Staphylococcus aureus
PubMed: 35730963
DOI: 10.1128/spectrum.01039-22 -
Journal of Equine Science Sep 2022Cephalothin (CET) concentrations in body fluids (plasma, synovial fluid, pleural fluid, peritoneal fluid, and aqueous humor) and tissue samples (bone, lung, jejunum,...
Cephalothin (CET) concentrations in body fluids (plasma, synovial fluid, pleural fluid, peritoneal fluid, and aqueous humor) and tissue samples (bone, lung, jejunum, hoof, and subcutaneous tissue) were investigated to consider the treatment of infectious diseases in horses. CET 22 mg/kg body weight was intravenously administered to 12 horses. Samples were collected from four different horses at 1, 3, and 5 hr after administration. The CET concentration in body fluids other than aqueous humor was maintained above the MIC values of Streptococcus zooepidemicus and Staphylococcus aureus until 5 hr, but it was not maintained above that of S. aureus in bone. CET (22 mg/kg twice a day) is effective for septic arthritis, pleuritis, and peritonitis caused by gram-positive bacteria but ineffective for osteomyelitis.
PubMed: 36196140
DOI: 10.1294/jes.33.51 -
Antimicrobial Agents and Chemotherapy Sep 1974Cefoxitin, a semisynthetic cephamycin, has been compared with the widely used parenteral cephalosporin, cephalothin, in terms of antibacterial activity, human... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
Cefoxitin, a semisynthetic cephamycin, has been compared with the widely used parenteral cephalosporin, cephalothin, in terms of antibacterial activity, human pharmacokinetics, and toxicity. For both compounds, minimal inhibitory concentrations were within the therapeutic range against the 156 gram-positive cocci tested (except group D streptococci), but cephalothin was 8 to 20 times more active. Regarding the 313 gram-negative organisms tested, both antibiotics were of approximately equal activity against cephalothin-susceptible strains, but cefoxitin was outstandingly superior against Providencia spp. and indole-producing Proteus spp., and markedly better against Serratia marcescens and Bacteroides fragilis. Against these organisms, cefoxitin but not cephalothin would be expected to be therapeutically valuable. Antibiotic activity levels in the serum and urine of 18 human volunteers after parenteral administration were higher and more prolonged in the case of cefoxitin, which had an average terminal serum half-life of about 45 min and a urinary recovery of about 90%. Cefoxitin was entirely nontoxic and, given intramuscularly, slightly less painful then cephalothin. These preliminary results suggest that cephamycins may prove to be a significant chemotherapeutic advance.
Topics: Adult; Anti-Bacterial Agents; Biological Availability; Cefoxitin; Cephalothin; Humans; Male; Microbial Sensitivity Tests
PubMed: 15830475
DOI: 10.1128/AAC.6.3.290