Susceptibility of Clostridium perfringens Isolated from Human Infections to Twenty Antibiotics

Abstract

The proper choice of antibiotic for Clostridium perfringens infections in patients allergic to penicillin is not dear; the usual recommendations and recent in vitro studies disagree. We tested the susceptibility of 57 strains ofC. perfringens to eight penicillins, seven cephalosporins, two tetracyclines, clindamycin, chloramphenicol, and rifampin by the agar dilution method. All strains were inhibited by (per milliliter) 4 ,ug or less of any of the penicillins, chloramphenicol, or clindamycin and 8 ,mg or less of any of the cephalosporins tested. Penicillin G and amoxicillin inhibited all strains at 0.12 ,g or less per ml. Only 54% of the strains were inhibited by 1 ,ug of tetracycline per ml. Penicillin G remains the drug of first choice for infections with C. perfringens; it need not be added to a regimen containing a penicillinase-resistant penicillin given parenterally in high doses. The cephalosporins should be considered as alternative drugs for penicillin-allergic patients. Clindamycin and chloramphenicol are also effective. Tetracyclines cannot be depended upon in clostridial infections without in vitro testing, which is impracticable for initial empirical therapy.Penicillin G is the antibiotic of first choice for treating cellulitis, sepsis, and myonecrosis caused by Clostridium perfringens (1, 2,8,11,18). Although erythromycin and tetracycline are the alternative drugs usually recommended (1, 2,8,11,18), 10 to 30% of C. perfringens are resistant to tetracycline, and a few strains are also resistant to erythromycin (6,8,9,13). Cephalosporins and penicillinase-resistant and other semisynthetic penicillins are used for contaminated wounds after severe trauma and for suspected sepsis in patients with cancer, who are also at a higher risk for clostridial infections (3,4,14). Because of both scanty information about many of these agents and the need for a safe antibiotic for penicillin-allergic patients, we studied the activity of 20 antibiotics against strains of C. perfringens isolated from human infections or feces. Susceptibility testing. Agar dilution tests were done by the method of Sutter and Washington (15). MATERIALSAntibiotics were diluted in twofold steps above and below 1 pg/ml in Brucella agar (Pfizer) supplemented with 5% laked sheep blood and vitamin K1 (10 ug/ml). The inoculum was adjusted to a no. 1 MacFarland turbidity standard (3 x 108 colonyforming units) and then diluted with prereduced Carey-Blair buffer, so that each spot delivered by 695 on May 9, 2018 by guest http://aac.asm.org/ Downloaded from

Isolation and Characterization of Multiply Antibiotic-Resistant Clostridium perfringens Strains from Porcine Feces

“…Sapico et al (25) being susceptible to 12.5 ,.g of Ln per ml. Other studies on Cc (21,22,26,32,33,38) or Ln (21,22,38) as well as Em (15,21,22,25,33) failed to detect strains with MICs of 16 ug/ml or higher. However, the strain studied by Sebald et al (27) Their results appear to be somewhat different from those of the above-mentioned workers, as the incidence of resistant strains was higher.…”

“…In general, the strains examined were all susceptible to Pc and Cm (15,21,22,25,26,33). Staneck and Washington (32) reported that of 24 C. perfringens strains examined 96% were susceptible to Pc at 0.4 ,g/ml, but that one strain had an MIC of 12.5 ug/ml.…”

Effect of antibiotics on toxin production and viability of Clostridium perfringens

“…The MICs of rifampin, tetracycline, and clindamycin were 0.03, 0.05, and 0.07 pug/ml, respectively. The MICs of penicillin G and metronidazole were 0.27 and 0.69 ,ug/ml, respectively, and within the range of values previously reported by others (6,15,23,29). In contrast, chloramphenicol had an MIC of 1.50 pug/ml which is slightly higher than the MIC50 (MIC for 50% of the strains tested) of 1.0 ,g/ml, but less than the MIC90 of 4 pg/ml reported previously (15).…”

“…However, antibiotic susceptibility studies, including the present study ( and metronidazole might also be effective drugs for the treatment of C. perfringens infections (6,15,18,23 turbidity was reduced to base-line levels (zero time) by 15 to 30 min for all drugs tested except penicillin and chloramphenicol. In sharp contrast, penicillin produced only a 38% reduction in turbidity by 45 min, despite a 102 CFU reduction in bacteria at that time.…”

Caracterização molecular dos principais fatores de virulência e genótipos de Clostridium perfringens isolados de frangos com enterite necrótica.

“…Por outro lado, tem sido demonstrado que este microrganismo após o contato com células epiteliais, tais como Caco-2, HT-29 e MDCK, imediatamente após sua adesão, têm a capacidade de produzir toxinas e neuraminidases, e esta resposta também é regulada pelo Sistema VirR/VirS VIDAL et al, 2012 WANG, 1977;WATKINS et al, 1997;WILLIAMSON, 1983).…”