detection using polymerase chain reaction. This bacterium can be effectively treated with β-lactam antibiotics, which inhibit cell wall synthesis. It can also be treated with fluoroquinolones or tetracyclines; fluoroquinolones inhibit bacterial DNA synthesis and tetracyclines interfere with protein synthesis by binding to the bacterial 30S ribosomal subunit. Despite poor in vitro susceptibility results, macrolides (binding to the ribosome) also can be applied, certainly in the case of pulmonary complications. Due to the polymicrobial etiology of P. multocida infections, treatment requires the use of antimicrobials targeted at the elimination of both aerobic and anaerobic, Gram-negative bacteria. As a result, amoxicillin-clavulanate (a beta-lactamase inhibitor/penicillin combination) is seen as the treatment of choice. Current research P. multocida mutants are being researched for their ability to cause diseases. In vitro experiments show the bacteria respond to low iron. Vaccination against progressive atrophic rhinitis was developed by using a recombinant derivative of P. multocida toxin. The vaccination was tested on pregnant gilts (female swine without previous litters). The piglets born to treated gilts were inoculated, while the piglets born to unvaccinated mothers developed atrophic rhinitis. Other research is being done on the effects of protein, pH, temperature, sodium chloride (NaCl), and sucrose on P. multocida development and survival in water. The research seems to show the bacteria survive better in water compared to water. The addition of 0.5% NaCl also aided bacterial survival, while the sucrose and pH levels had minor effects, as well. Research has also been done on the response of P. multocida to the host environment. These tests use DNA microarrays and proteomics techniques. P. multocida-directed mutants have been tested for their ability to produce disease. Findings seem to indicate the bacteria occupy host niches that force them to change their gene expression for energy metabolism, uptake of iron, amino acids, and other nutrients. In vitro experiments show the responses of the bacteria to low iron and different iron sources, such as transferrin and hemoglobin. P. multocida genes that are upregulated in times of infection are usually involved in nutrient uptake and metabolism. This shows true virulence genes may only be expressed during the early stages of infection. Genetic transformation is the process by which a recipient bacterial cell takes up DNA from a neighboring cell and integrates this DNA into the recipient’s genome. P. multocida DNA contains high frequencies of putative DNA uptake sequences (DUSs) identical to those in Hemophilus influenzae