&lt;i&gt;In vitro&lt;/i&gt; Activity of Chloramphenicol Combined with Cephalothin against DNase-Positive, Multiple-Antibiotic Resistant Strains of &lt;i&gt;Staphylococcus epidermidi&lt;/i&gt;&lt;i&gt;s&lt;/i&gt;

Wh, Traub

doi:10.1159/000220687

Cited by 5 publications

(5 citation statements)

References 7 publications

(10 reference statements)

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“…There was, however, a striking relationship between the outcome of the combined action of chloramphenicol and betalactam and the sensitivity to the beta-lactam alone. On 83 occasions chloramphenicol was combined with a beta-lactam that was active on its own; in 61 (73%) antagonism was found, and on only one occasion (1.2%) synergism; indifference was seen in the remaining 21 To elucidate the mechanism of this synergistic effect, 10 strains of beta-lactamase-producing gram-negative bacteria were studied with combinations of chloramphenicol and cephaloridine. The enzyme was constitutive in eight strains and inducible in two.…”

Section: Resultsmentioning

confidence: 99%

Mechanism of Chloramphenicol-Cephaloridine Synergism on Enterobacteriaceae

Michel

Bornstein

Luboshitzky

et al. 1975

Antimicrob Agents Chemother

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A synergistic in vitro bactericidal effect of combinations of chloramphenicol and beta-lactams on strains of Enterobacteriaceae is described. The synergism is seen with strains which are resistant to the beta-lactam and is due to chloramphenicol-induced inhibition of beta-lactamase production.The increasing resistance of gram-negative bacilli to anti-bacterial agents (6), including gentamicin (12) and the cephalosporins (19), raises the possibility of having to resort to a synergistic combination of drugs in the therapy of infections caused by these bacteria.Synergism between chloramphenicol and several beta-lactam antibiotics on strains of Klebsiella-Enterobacter-Serratia, which are resistant to the beta-lactam alone, has recently been described as a not uncommon event (13). The present study was undertaken to examine the occurrence of this synergism with gram-negative bacilli belonging to other genera, and to elucidate its mechanism.MATERIALS AND METHODS Bactericidal effect of combinations of chloramphenicol and three beta-lactams. Ninety-four strains of Enterobacteriaceae isolated in the diagnostic laboratory of the Department of Clinical Microbiology, Hadassah University Hospital, from sputum, infected wounds, stools, and blood cultures were studied. These strains were identified according to Ewing (5) as Escherichia coli (15 strains), Shigella (15 strains), Citrobacter (3 strains), Salmonella (12 strains), Proteus (13 strains), Providence (6 strains), Klebsiella (11 strains), Enterobacter (9 strains), and Serratia (10 strains). The cellophane transfer technique of Chabbert (1) as modified by Cluzel et al. (4) was used to determine a synergistic bactericidal effect. The principles and techniques of this method have recently been described and illustrated in detail (3,7,8,16). The results were interpreted according to previously reported criteria and were classified as synergism, antagonism, or indifference (3,7,8,16). The beta-lactams used were ampicillin, cephaloridine, and carbenicillin.Mechanism of synergistic effect. For these experiments the following strains of beta-lactamase-producing Enterobacteriaceae were used: Enterobacter cloacae NCTC 10005, Klebsiella pneumoniae K 1296 obtained from John Matsen, University of Minnesota (14), and eight strains (see Table 2) isolated from clinical material at the Hadassah University Hospital and identified according to Ewing (5). Each strain was tested for beta-lactamase production by the iodometric method as described by Workman and Farraz (22).Susceptibility to single antibiotics. The susceptibility of these strains to chloramphenicol and cephaloridine was determined by preparing doubling dilutions of the antibiotic in Trypticase soy broth (TSB; Difco). The inoculum was 0.1 ml of a suitably diluted overnight culture in TSB to give a final concentration in the test dilutions of approximately 105 bacteria/ml. The minimal inhibitory concentration (MIC) was expressed in terms of the lowest concentration of antibiotic that totally inhibited visible growth after 24 h...

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Section: Resultsmentioning

confidence: 99%

Mechanism of Chloramphenicol-Cephaloridine Synergism on Enterobacteriaceae

Michel

Bornstein

Luboshitzky

et al. 1975

Antimicrob Agents Chemother

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“…As the important and wide‐spectrum, synthetic antibacterial, FF is frequently used in livestock and fishery husbandries by intramuscular or oral routes of administrations (Wang et al., ). Additionally, FF has been proposed to cure not only chloramphenicol‐sensitive pathogens such as Pasteurella multocida , Pasteurella haemolytica, and Haemophilus sommus , but also E. coli , Staphylococcus aureus , and Salmonella typhimurium (Bala, Yakubu, Abdullahi, & Ella, ; Lei, Liu, Qi, et al., ; Lei, Liu, Yang, Ahmed, et al., ; Lei, Liu, Yang, Yang, et al., ; Lei, Liu, Zhu, et al., ; Messick & Pendland, ; O'Grady, Pearson, & Dennis, ; Traub, ). In this study, 10% water‐soluble FF powder was developed as a kind of new formulation against E. coli .…”

Section: Discussionmentioning

confidence: 99%

Resistant cutoff values and optimal scheme establishments for florfenicol against Escherichia coli with PK‐PD modeling analysis in pigs

Lei

Liu

Khaliq

et al. 2019

Vet Pharm & Therapeutics

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Florfenicol, a structural analog of thiamphenicol, has broad‐spectrum antibacterial activity against gram‐negative and gram‐positive bacteria. This study was conducted to investigate the epidemiological, pharmacokinetic–pharmacodynamic cutoff, and the optimal scheme of florfenicol against Escherichia coli (E. coli) with PK‐PD integrated model in the target infectious tissue. 220 E. coli strains were selected to detect the susceptibility to florfenicol, and a virulent strain P190, whose minimum inhibitory concentration (MIC) was similar to the MIC50 (8 μg/ml), was analyzed for PD study in LB and ileum fluid. The MIC of P190 in the ileum fluid was 0.25 times lower than LB. The ratios of MBC/MIC were four both in the ileum and LB. The characteristics of time‐killing curves also coincided with the MBC determination. The recommended dosages (30 mg/kg·body weight) were orally administrated in healthy pigs, and both plasma and ileum fluid were collected for PK study. The main pharmacokinetics (PK) parameters including AUC24 hr, AUC0–∞, Tmax, T1/2, Cmax, CLb, and Ke were 49.83, 52.33 μg*h/ml, 1.32, 10.58 hr, 9.12 μg/ml, 0.50 L/hr*kg, 0.24 hr−1 and 134.45, 138.71 μg*hr/ml, 2.05, 13.01 hr, 16.57 μg/ml, 0.18 L/hr*kg, 0.14 hr−1 in the serum and ileum fluid, respectively. The optimum doses for bacteriostatic, bactericidal, and elimination activities were 29.81, 34.88, and 36.52 mg/kg for 50% target and 33.95, 39.79, and 42.55 mg/kg for 90% target, respectively. The final sensitive breakpoint was defined as 16 μg/ml. The current data presented provide the optimal regimens (39.79 mg/kg) and susceptible breakpoint (16 μg/ml) for clinical use, but these predicted data should be validated in the clinical practice.

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“…First-and second-generation cephalosporins are rarely used in combination with chloramphenicol, as reflected by the paucity of studies regarding their synergy or antagonism (17). Since the introduction of new cephalosporins that can be used reasonably in bacillary meningitis, the coadministration of a cephalosporin with chloramphenicol might be considered.…”

Section: Resultsmentioning

confidence: 99%