Colonies of B. pseudomallei that are grown on Francis medium (a modification of Ashdown medium with gentamicin concentration increased to 8 mg/L and neutral red indicator replaced with 0.2% bromocresol purple) are yellow. For laboratories located outside endemic areas, Burkholderia cepacia selective agar can be used if Ashdowns medium is not available. It is important not misinterpret the bacterial growth as Pseudomonas or Bacillus spp. Other biochemical screening tools can also be used for detecting B. pseudomallei, including the API 20NE or 20E biochemical kit combined with Gram stain, oxidase test, typical growth characteristics, and resistance to certain antibiotics of the bacteria. API 20NE biochemical kit is 99% sensitive in identifying B. pseudomallei.Molecular methods such as 16S rDNA sequencing, multiplex polymerase chain reaction (PCR), and real-time PCR can also be used to identify B. pseudomallei in culture. Other bacterial genes such as fliC genes encoding flagellin, rpsU gene encoding for ribosomal protein, and TTS genes encoding Type III secretion systems has also been employed for detection. Another method of gene detection namely multiple cross displacement amplification for the bacterial TTS1 gene detection produces results within an hour. Hematological and biochemical tests
General blood tests in people with melioidosis show low white blood cell counts (indicates infection), raised liver enzymes, increased bilirubin levels (indicates liver dysfunction), and raised urea and creatinine levels (indicates kidney dysfunction). Low blood glucose and acidosis predicts a poorer prognosis in those with melioidosis. However, other tests such as C-reactive protein and procalcitonin levels are not reliable in predicting the severity of melioidosis infection.
There is little evidence in supporting the use of melioidosis prophylaxis in humans. The antibiotic co-trimoxazole is used as a preventative only for individuals at high risk for getting the disease after being exposed to the bacteria in laboratory settings. One study conducted in 2018 determined that the drug could be useful in preventing melioidosis in high-risk renal failure patients undergoing haemodylysis. There is no approved vaccine for melioidosis.Approximately 165,000 people are infected by melioidosis per year, resulting in about 89,000 deaths, based on a mathematical model published in 2016. Diabetes is a major risk factor for melioidosis; over half of melioidosis cases are in people with diabetes. Increased rainfall and severe weather events such as thunderstorm are associated with an increased number of melioidosis cases in endemic areas. Signs and symptoms
Acute
Most people exposed to B. pseudomallei experience no symptoms. The mean incubation period of acute melioidosis is 9 days (range 1–21 days). Nevertheless, symptoms of melioidosis can appear in 24 hours for those who experienced near drowning in water. Those affected present with symptoms of sepsis (predominantly fever) with or without pneumonia, or localised abscess or other focus of infection. The presence of non-specific signs and symptoms has caused melioidosis to be nicknamed "the great mimicker".Diabetes mellitus is one of the most important risk factors in developing melioidosis. The disease should be considered in anyone who has spent time in endemic areas who develops a fever, pneumonia, or abscesses in their liver, spleen, prostate, or parotid gland.