Studies on Certain Biological Characteristics of Malleomyces mallei and Malleomyces pseudomallei

Abstract

As a natural infection, glanders occurs only in horses, mules, and donkeys. Other animals occasionally become infected from contact with infected solipeds. The most susceptible of these occasionally infected species are ferrets, moles, field mice, cats, and dogs. Sheep, goats, hogs, rabbits, white, mice, and house mice are reported to be less susceptible, and cattle are iune (Hutyra and Marek, 1926). The guinea pig is considered to be the most susceptible laboratory animal. The virulence of various strains of Malleomyces mallei has been reported to vary widely (Bernstein and Carling, 1909; Dudgeon et al., 1918), but in the virulence tests recorded in the literature large doses were given, and evaluation of virulence was made solely on the severity of disease produced. The wild rats of southeastern Asia constitute a natural reservoir of melioidosis. The disease, chronic in the rat, is thought to be transmitted to other animals, and to man, by ingestion or inhalation of materials contaminated with rat exereta. Rabbits, dogs, and cats have been found infected naturally, and an occasional case of infection has been reported in other domestic animals. Guinea pigs, mice, and rabbits have been used in studies of the experimentally produced disease (Stanton and Fletcher, 1932). Guinea pigs were reported to be almost universally susceptible, dying of a fulminating infection within 24 hours after a massive inoculation and within 3 weeks after a smaller inoculation. Monkeys were more resistant, developing fatal infection only after ingestion of massive doses. Rabbits and guinea pigs were susceptible to inoculation by the intraperitoneal or subcutaneous routes and by ingestion and inhalation. Although the organisms were reported as highly virulent, the inoculum always contained thousands to millions of organisms (0.01 to 1 ml of a 48-hour broth culture-Stanton and Fletcher, 1932). No reference to a more quantitative evaluation of virulence by MLD or LDr0 determinations was found in the literature.

Type III secretion system cluster 3 is required for maximal virulence ofBurkholderia pseudomalleiin a hamster infection model

“…Isolates were injected intraperitoneally into hamsters, and lethality was determined by observation for 2 days ( Table 3). The 95% confidence intervals were determined to be 1.340-3.610.DD503 was previously reported to have a 48 h log LD 50 value of less than 1 [24], and we further estimated the log LD 50 to be 0.6021 (Table 3), which is consistent with the published log LD 50 of B. pseudomallei in hamsters of 0.7782 [25]. Both the DsctU Bp1 and DsctU Bp2 mutants had LD 50 values similar to the parental strain; however, the DsctU Bp3 mutant was significantly attenuated with a log LD 50 of 3.3802 cfu.…”

Burkholderia mallei infection in a horse imported from Brazil

“…Due to the low number of bacteria in infected tissues, abscess material and excreted pus, cultivation on solid or in liquid media is often negative, particularly if samples originate from subclinical or chronic cases (Bongert 1927;Miller et al 1948;Arun et al 1999).…”

Comparative experimental subcutaneous glanders and melioidosis in the common marmoset (Callithrix jacchus)

“…Little work has been undertaken in non-human primates (NHP). In the 1940's, six Macaca mulatta were challenged subcutaneously with B. mallei, with all animals surviving the challenge and one animal exhibited a raised fever with an abscess at the site of inoculation (Miller et al 1948). Studies reported in the 1990's have involved both subcutaneous and intravenous B. mallei challenge in NHP's, specifically baboons, but details of the disease presentation are sparse (Manzeniuk et al 1996;Khomiakov et al 1998;Mukhopadhyay et al 2004).…”

“…Studies reported in the 1990's have involved both subcutaneous and intravenous B. mallei challenge in NHP's, specifically baboons, but details of the disease presentation are sparse (Manzeniuk et al 1996;Khomiakov et al 1998;Mukhopadhyay et al 2004). Early studies investigating experimental melioidosis in NHPs were performed in the 1920's and 1940's where macaques were infected by either the oral or subcutaneous route (Stanton & Fletcher 1925;Miller et al 1948). All animals survived the challenge with minimal, if any, clinical observations.…”