Glanders is caused by the bacterium Burkholderia mallei which is also known as Pseudomonas mallei. The bacteria can be found only in the infected susceptible host and it cannot be found in the water, soil and plants. Normally humans acquires glanders from equids via direct contact with the broken skin or mucous membranes. The bacteria can also be transmitted through the intact skin. The secondary mode of transmission is through the droplets from the infected equid or patients.
Once in the host synthesis and release of certain toxins can occur. The amount of the toxins released is insignificant and no clinical disease process is ensured. The symptoms depends upon the amount o the toxins released by the organisms. The toxin released by the bacteria is called as pyocyanin a blue green pigment that interferes with the terminal electron transfer system, lecithinase which might result in the cell lysis by degrading lecithin in certain cell membranes, collagenase, lipase and hemolysin. Melioidosis is an infectious disease caused by B. pseudomallei ( Formerly P pseudomallei). The organism is widely present in the soil and water of the tropical region. It is spread to the humans via direct contact with the contaminated source, mainly during the rainy seasons. The disease more commonly occurs in the person who has other comorbidities such as diabetes, hypertension, alcoholism , immunosuppression and renal failure.
B.pseudomalle is considered as a biological weapon which can be used in the bioweapons. It is highly potentially to become bacteremic thereby increasing the chances of morbidity and mortality rates. The incubation period in naturally acquired infections can vary from days to months to years. The incubation period after an aerosol attack is expected to be from 10-14 days. Glanders is similar to the melioidosis such that the both produces the similar infections.
Bacteria enter the skin through a laceration or abrasion or by breakage in mucous membrane, and a local infection with ulceration develops. The incubation period is 1-5 days. Swollen lymph glands may develop. Bacteria that enter the host through mucous membranes can cause increased mucus production in the affected areas.
When bacteria are aerosolized and enter the respiratory tract via inhalation or hematogenous spread, pulmonary infections may develop. Pneumonia, pulmonary abscesses, and pleural effusions can occur. The incubation period is 10-14 days. With inhalational melioidosis, cutaneous abscesses may develop and take months to appear.
When bacteria is transmitted in the bloodstream in glanders, it is usually fatal within 7-10 days. The septicemia that develops affects multiple systems, and cutaneous, hepatic, and splenic involvement may or may not occur. With melioidosis, bacteremia is observed with chronically ill patients (eg, patients with HIV, patients with diabetes). They develop respiratory distress, headaches, fever, diarrhea, pus-filled lesions on the skin, and abscesses throughout the body. Septicemia may be overwhelming, with a 90% fatality rate and death occurring within 24-48 hours.
The chronic form involves multiple abscesses, which may affect the liver, spleen, skin, or muscles. This form is also known as farcy in glanders disease. Melioidosis, in addition to this chronic form, can become reactive many years after the primary infection.