Alcaligenes faecalis - Research Paper Example

It is found in the alimentary tract as a harmless saprophyte in 5% to 19% of the normal population. This organism does not usually cause systemic infection. Alcaligenes faecalis has been reported to cause “sepsis, meningitis, peritonitis, enteric fever, appendicitis, cystitis, chronic suppurative otitis media, abscesses, arthritis, pneumonitis, and endocarditis” (Kavuncuoglu et al 118). Because Alcaligenes faecalis is resistant to commonly used antibiotics, the organism is associated with fatal outcomes.

Thesis Statement: The purpose of this paper is to investigate Alcaligenes faecalis, and examine various aspects of the organism, its morphology and effects. Taxonomy, Morphology and Functions of Alcaligenes faecalis Hans Riemann and Dean O. Cliver argue that food borne diseases are increasing because of accelerated globalization of food supply, and emphasize the importance of finding new ways of detecting and identifying foodborne pathogens, and the elimination of food-related infections and intoxications.

“Alcaligenes faecalis is a Gram-negative, oxidase-positive, and catalase-positive microorganism shaped in the form of a rod, coccal-rod or coccal” (Riemann and Cliver 343). The obligate aerobic bacterium moves with the help of peritrichous flagella, usually eight in number, but may occasionally be up to twelve. Some strains of the microorganism are capable of anaerobic respiration in the presence of nitrate or nitrite (Riemann and Cliver 343). Alcaligenes faecalis generally exists singly, and has a size of 0.5 – 1.0 x 0.5 – 2.6 um.

The organism grows optimally at a temperature range of 20-370C. Although not considered as a major food-borne pathogen, it has caused occasional food-borne outbreaks with the typical symptoms of abdominal pain, headache, vomiting and diarrhoea. Further, “A. faecalis is an important food spoilage bacterium” ((Riemann and Cliver 344). Besides soil and water, the organism has been isolated from various sources such as medical specimens including body fluids and body waste matter, and from nematodes and insects.

Some species of A. faecalis are commonly found in the intestinal tracts of vertebrates (Riemann and Cliver 344). The scientific classification of Alcaligenes faecalis (Vasanthakumari 335) is as follows: Kingdom: Bacteria Phylum: Proteobacteria Class: Beta Proteobacteria Order: Burkholderiales Family: Alcaligenaceae Genus: Alcaligenes Species: Alcaligenes faecalis (Vasanthakumari 335) Fig.1. White, Glistening Colonies of Alcaligenes faecalis on Blood Agar (Herrera, 2012) Paul G. Engelkirk and Janet L.

Duben-Engelkirk observe that identification of Gram staining Alcaligenes faecalis and CDC Alcaligenes – like group 1 reveals that they cannot be differentiated from other non-fermenters. They have similar cellular morphology, and are motile by peritrichous flagella. The colonial morphology reveals that A. faecalis produces white colonies with a thin, spreading, irregular edge (Fig.1). Older colonies, as shown in the illustration above “tend to spread at the periphery and turn the agar a green-apple color” ((Engelkirk and Duben-Engelkirk 332). James T. Staley, Don J.

Brenner, Noel R. Krieg and co-authors observe that the type subspecies faecalis of the Species Alcaligenes faecalis contains the type strain of the species. Its morphological characteristics are the same as those of the Genus Alcaligenes. Colonies of the organism on nutrient agar range in