High dose of co-amoxiclav (20 mg/kg for amoxicillin and 5 mg/kg for clavulanate) is recommended to prevent treatment failures. Intravenous antibiotics are given for a minimum of 10 to 14 days. The median fever clearance time in melioidosis is 9 days. The treatment duration is in accordance with Darwin melioidosis treatment guidelines where there is low rate of recrudescence and relapse.Meropenem is the preferred antibiotic therapy for neurological melioidosis and those with septic shock admitted into intensive care units. Co-trimoxazole is recommended in addition to ceftazidime for neurological melioidosis, osteomyelitis, septic arthritis, skin and gastrointestinal infection, and deeply seated abscess. For deep-seated infections such as abscesses of internal organs, osteomyelitis, septic arthritis, and neurological melioidosis, the duration of antibiotics given should be longer (up to 4 to 8 weeks). The time taken for the fever to be resolved can be more than 10 days in those with deep-seated infection. According to the 2020 Revised Royal Darwin Hospital Guideline, the dosage for intravenous ceftazidime is 2g 6-hourly in adults (50 mg/kg up to 2g in children less than 15 years old). The dosage for meropenem is 1g 8-hourly in adults (25 mg/kg up to 1g in children). Acquired resistance to ceftazidime, carbapenems, and co-amoxiclav is rare in the intensive phase but resistance to cotrimoxazole during eradication therapy is technically difficult to assess. There are no differences between using cefoperazone/sulbactam or ceftazidime to treat melioidosis as both shows similar death rates and disease progression following treatment. However, data are lacking to recommend cefoperazone/sulbactam usage.
B. pseudomallei triggers both the complement system and coagulation cascade, however the thick bacterial capsule prevent the action of the complement membrane attack complex.Additional elements of the immune system are activated by the host toll-like receptors such as TLR2, TLR4, and TLR5 that recognize the conserved pieces of the bacteria such as LPS and flagella. This activation results in the production of cytokines such as Interleukin 1 beta (IL-1β) and Interleukin 18 (IL-18). IL-18 increases IFN production through natural killer cells while IL-1beta reduces the IFN production. These immune molecules drive the recruitment of other immune cells such as neutrophils, dendritic cells, B cells, and T cells to the site of infection. T cells seem to be particularly important for controlling B. pseudomallei; T cell numbers are increased in survivors, and low T cell numbers are associated with a high risk of death from melioidosis. Despite this, HIV infection is not a risk factor for melioidosis. Although macrophages show deregulated cytokine responses in individuals with HIV infection, bacterial internalization and intracellular killing are still effective. People infected with B. pseudomallei may develop antibodies against the bacteria, and people that live in endemic areas tend to have antibodies in their blood that recognize B. pseudomallei. However, the effectiveness of these antibodies at preventing melioidosis is unclear.B. pseudomallei can remain latent in the human body for up to 29 years until it is reactivated during human immunosuppression or stress response.