It can also survive in antiseptic and detergent solutions, acidic environments (pH 4.5 for 70 days), and in environments at temperatures ranging from 24 °C (75.2 °F) to 32 °C (89.6 °F). However, the bacteria may be killed by the presence of ultraviolet light.Bacteria can enter the body through wounds, inhalation, and ingestion of contaminated soil or water. Person-to-person transmission is extremely rare. Melioidosis is a recognised disease in animals including pigs, cats, dogs, goats, sheep, horses and others. Cattle, water buffalo, and crocodiles are considered to be relatively resistant to melioidosis despite their constant exposure to mud. Birds are also considered resistant to melioidosis although several cases had been reported in Australia and aquatic birds. Transmission from animals to humans is rare.Inadequate chlorination of water supply has been associated with B. pseudomallei outbreak in Northern and Western Australia. The were also several cases of where bacteria have also been found in unchlorinated water supply in rural Thailand. Based on the whole genome sequencing of the bacteria, the variety of the bacteria B. pseudomallei in Papua New Guinea is narrow due to limited movements of the indigenous people. This findings supports the hypothesis that humans play an important role in bacterial transmission. Pathogenesis
B. pseudomallei has the ability to infect various types of cells and to evade human immune responses. Bacteria first enter at a break in the skin or mucous membrane and replicate in the epithelial cells. From there, they use flagellar motility to spread and infect various cell types.
The choice of antibiotics depends upon the susceptibility of the bacteria to various antibiotics. B. pesudomallei are generally susceptible to ceftazidime, meropenem, imipenem, and co-amoxiclav. These drugs generally kill bacteria. B. pseudomallei is also susceptible to doyxcycline, chloramphenicol, and co-trimoxazole. These drugs generally inhibit the growth of the bacteria. However, the bacteria are resistant to penicillin, ampicillin, 1st and 2nd generation cephalosporin, gentamicin, streptomycin, tobramycin, macrolides, and polymyxins. On the other hand, 86% of the B. pseudomallei isolates from the region of Sarawak, Malaysia are susceptible to gentamicin and this has not been found elsewhere in other parts of the world.Prior to 1989, the standard treatment for acute melioidosis was a three-drug combination of chloramphenicol, co-trimoxazole and doxycycline; this regimen is associated with a mortality rate of 80% and is no longer used unless no other alternatives are available. All three drugs are bacteriostatic (they stop the bacterium from growing, but do not kill it) and the action of co-trimoxazole antagonizes both chloramphenicol and doxycycline. Intensive phase
Intravenous ceftazidime is the current drug of choice for treatment of acute melioidosis and should be administered for at least 10 to 14 days. Meropenem, imipenem and the cefoperazone-sulbactam combination (Sulperazone) are also effective. Intravenous amoxicillin-clavulanate (co-amoxiclav) may be used if none of the above four drugs is available; co-amoxiclav prevents death from melioidosis as well as ceftazidime. Co-amoxiclav is also used if patient has allergy towards sulfonamide, unable to tolerate co-trimaxazole, in pregnant patients or in children.