Which organism is the causative agent of melioidosis?

Which organism is the causative agent of melioidosis?

• A. Burkholderia cepacia
• B. Burkholderia pseudomallei
• C. Moraxella catarrhalis
• D. Stenotrophomonas maltophilia

Answer: (B)

Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative, aerobic rod that dwells in soil and surface water in tropical regions such as Southeast Asia and northern Australia. Exposure typically occurs through skin wounds, inhalation of contaminated dust or water, or ingestion, which is why agricultural workers and rice farmers in endemic areas are at higher risk. The disease can present in a wide range of forms—from localized infections to severe septicemia with multiple organ abscesses—making the organism’s environmental reservoir and pathogenic versatility key to understanding the illness. The other organisms listed are different opportunistic pathogens with distinct disease associations: Burkholderia cepacia complex is mainly a concern in cystic fibrosis patients and hospital outbreaks; Moraxella catarrhalis commonly causes upper respiratory infections; Stenotrophomonas maltophilia is a nosocomial pathogen in debilitated patients. None of these cause melioidosis, which is specifically linked to Burkholderia pseudomallei.

Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative, aerobic rod that dwells in soil and surface water in tropical regions such as Southeast Asia and northern Australia. Exposure typically occurs through skin wounds, inhalation of contaminated dust or water, or ingestion, which is why agricultural workers and rice farmers in endemic areas are at higher risk. The disease can present in a wide range of forms—from localized infections to severe septicemia with multiple organ abscesses—making the organism’s environmental reservoir and pathogenic versatility key to understanding the illness.

The other organisms listed are different opportunistic pathogens with distinct disease associations: Burkholderia cepacia complex is mainly a concern in cystic fibrosis patients and hospital outbreaks; Moraxella catarrhalis commonly causes upper respiratory infections; Stenotrophomonas maltophilia is a nosocomial pathogen in debilitated patients. None of these cause melioidosis, which is specifically linked to Burkholderia pseudomallei.