J Vet Sci.  2019 Jan;20(1):58-62. 10.4142/jvs.2019.20.1.58.

Evaluation of in vitro antimicrobial susceptibility of Bacillus anthracis strains isolated during anthrax outbreaks in Italy from 1984 to 2017

Affiliations
  • 1Anthrax Reference Institute of Italy, Experimental Zooprophylactic Institute of Puglia and Basilicata Regions, Foggia 71121, Italy. viviana.manzulli@izspb.it
  • 2Bundeswehr Institute of Microbiology, Munich 80937, Germany.
  • 3Department of Veterinary Medicine, University of Bari, Valenzano 70010, Italy.

Abstract

Anthrax, caused by Bacillus anthracis, is a non-contagious infectious disease that affects a wide range of animal species (primarily ruminants) including humans. Due to the often-fatal outcome in humans, quick administration of definitely effective antimicrobials is crucial either as prophylaxis or as a clinical case therapy. In this study, 110 B. anthracis strains, temporally, geographically, and genetically different, isolated during anthrax outbreaks in Italy from 1984 to 2017, were screened using a broth microdilution method to determine their susceptibility to 16 clinically relevant antimicrobial agents. The strains were isolated from various matrices (human, animal, and environmental samples) and were representative of thirty distinct genotypes previously identified by 15-loci multiple-locus variable-number of tandem repeats analysis. The antimicrobials tested were gentamicin, ceftriaxone, streptomycin, penicillin G, clindamycin, chloramphenicol, vancomycin, linezolid, cefotaxime, tetracycline, erythromycin, rifampin, amoxicillin, ciprofloxacin, doxycycline, and trimethoprim. All isolates were susceptible to most of the tested antimicrobials, with the exception of trimethoprim for which all of them showed high minimal inhibitory concentration values. An intermediate level of susceptibility was recorded for ceftriaxone and cefotaxime. Although the Centers for Disease Control and Prevention recommend the use of doxycycline, ciprofloxacin, penicillin G, and amoxicillin for treatment of human cases and for post-exposure prophylaxis to anthrax spores, this study shows a high degree of in vitro susceptibility of B. anthracis to many other antimicrobials, suggesting the possibility of an alternative choice for prophylaxis and therapy.

Keyword

Bacillus anthracis; Antimicrobial susceptibility testing; Anthrax treatment; Minimum inhibitory concentration

MeSH Terms

Amoxicillin
Animals
Anthrax*
Anti-Infective Agents
Bacillus anthracis*
Bacillus*
Cefotaxime
Ceftriaxone
Centers for Disease Control and Prevention (U.S.)
Chloramphenicol
Ciprofloxacin
Clindamycin
Communicable Diseases
Disease Outbreaks*
Doxycycline
Erythromycin
Genotype
Gentamicins
Humans
In Vitro Techniques*
Italy*
Linezolid
Methods
Microbial Sensitivity Tests
Penicillin G
Post-Exposure Prophylaxis
Rifampin
Spores
Streptomycin
Tandem Repeat Sequences
Tetracycline
Trimethoprim
Vancomycin
Amoxicillin
Anti-Infective Agents
Cefotaxime
Ceftriaxone
Chloramphenicol
Ciprofloxacin
Clindamycin
Doxycycline
Erythromycin
Gentamicins
Linezolid
Penicillin G
Rifampin
Streptomycin
Tetracycline
Trimethoprim
Vancomycin
Full Text Links
  • JVS
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2022 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr