New Antibiotic Sensitivity Testing Results

Nuflor®(florfenicol) an Excellent Choice for First-Line BRD Therapy

Antibiotic Sensitivity is a critical factor in choosing the correct antibiotic for the treatment of Bovine Respiratory Disease (BRD). A 2007 annual report from the Iowa State Veterinary Diagnostic
Laboratory describes the antimicrobial sensitivity patterns of the major bacterial pathogens causing BRD (Table 1 and Figure 1). Bacteria are tested under controlled laboratory settings by trained
microbiologists to determine the antibiotic sensitivity of disease-causing organisms. This information provides the veterinary practitioner valuable insight to optimize BRD therapy.

As you note, the results of antibiotic sensitivity testing are reported by the specific bacterial species and the generic antibiotic name (see Table 1 and Table 2).

Table 1: 2007 Antimicrobial Sensitivity Testing for Major Pathogens of BRD

Percentage (%) of BRD Isolates Susceptible to Various Antibiotics Following In Vitro MIC Testing
Antibiotic Mannheimia
haemolytica

(n=130)

Pastuerella
multocida

(n=119)

Histophilus
somni

(n=55)
Ceftiofur
100%
100%
100%
Danofloxacin
76%
88%
84%
Enrofloxacin
80%
93%
95%
Florfenicol
85%
90%
95%
Oxytetracycline
56%
70%
55%
Spectinomycin
72%
76%
67%
Tilmicosin
61%
64%
93%
Tulathromycin
80%
87%
86%

Table 2: Antibiotic Generic Trade Names Listed by Antibiotic Class

Antibiotic class Generic Names Antibiotic Trade Names
Beta Lactam Penicillin Duo-Pen,® Dura-Pen
Ceftiofur Naxcel,® Excenel,® Excede®
Fluoroquinolones Danofloxacin A180®
Enrofloxacin Baytril®
Phenicol Florfenicol Nuflor
 Tetracyclines Chlortetracycline Aureomycin,® CTC
Oxytetracycline Biomycin,® LA200,® Tetradure®
Macrolides Tilmicosin Micotil®
Tulathromycin Draxxin®

antibiotic sensitivity

Figure 1. Antibiotic Sensitivity Testing Results for Bacteria Causing BRD

These results indicate an excellent sensitivity profile for florfenicol against the primary pathogens of BRD.1There are other factors that are important in choosing an antibiotic, and many of these
factors allow for the injected antibiotic to reach the diseased tissues quickly and in high enough concentrations to treat disease.
Florfenicol is a very lipophilic antibiotic. This means that after injection with Nuflor,® florfenicol readily enters tissues, which results in wide distribution of antibiotic. When we take this new sensitivityinformation with the tissue distribution and speed of
action, we can be confident that Nuflor® (florfenicol) is an excellent first choice for treating BRD.

Antibiotic Selection Factors:

  • Spectrum of Activity
  • Speed of Action
  • Tissue Distribution
  • Antibiotic Sensitivity
  • Withdrawal Time

1 The correlation between in vitro suceptibility data and clinical response has not been determined for all antibiotics.