The three basic bacterial shapes are coccus sphericalbacillus rod-shapedand spiral twistedhowever pleomorphic bacteria can assume several shapes. Arrangement of cocci Cocci may be oval, elongated, or flattened on one side. Cocci may remain attached after cell division.
Propionibacteria are generally nonpathogenic; however, when certain species of Propionibacteria contaminate blood and other body fluid, they can cause a number of infections including the common skin disease acne vulgaris caused by P.
Some species of Propionibacteria are found in food like cheeses and other dairy products. The flavor derives from propionate, a product of fermentation, and the holes or "eyes" from bubbles of carbon dioxide. Genome Structure Currently there is one genome project that is complete on Propionibacterium acnes KPA, and there is one is progress on Nocardioides sp.
The entire genome sequence of P. Bacteria morphology more information see links above, left. Cell Structure and Metabolism Propionibacteria are slow-growing, nonsporeforming, Gram-positive, anaerobic bacteria.
They can be rod-shaped or branched and can occur singularly, in pairs, or in groups. They generally produce lactic acid, propionic acid, and acetic acid from glucose.
One species of Propionibacterium, P. The propionic acid produced from breaking down glucose is what gives Swiss cheese its characteristic flavor. Ecology Although Bacteria morphology acnes can be found on the skin of prepubesent humans, true colonization actually begins 1 to 3 years before sexual maturation.
Propionibacterium jensenii and Lactobacillus paracasei subsp. In fact, they inhibit these microbes up to 5 orders of magnitude at refrigerator temperatures 6oC without changing the quality of the food.
The bacterial mixture is effective against some yeasts, molds, and Gram-negative bacteria, but not other Gram-positive bacteria. During the tests on the inhibition activities of Propionibacterium sp. Therefore, it was assumed that something about the on-going processes of the cells and the P.
Pathology The three types of noninflammatory lesions caused by the accumulation of P. The four pathophysiologic features of acne, which occurs most often in the face, neck and back areas, are hyperkeratiniation, sebum production, bacterial proliferation, and inflammation.
Three categories of lesions formed during acne are noninflammatory lesions, inflammatory lesions, and scars. Three noninflammatory lesions include microcomedos, open comedos, which have a central impaction of keratin and lipid and might or might not be slightly raised, and closed comedos, which are slightly elevated papules that could possibly form into a larger inflammatory lesion.
Inflammatory lesions include more aggravated lesions such as pustules and large, fluctuant nodules. Propionibacteria have been known to cause, although rarely, brain abscesses, subdural empyema, dental infections, endocarditis, continuous ambulatory peritoneal dialysis, conjunctivitis associated with contact lenses, and peritonitits list from eMedicine.
Propionibacterium species can generally be treated with antibiotics used for the treatment of anaerobic infections; such antibiotics include penicillins, carbapenems, and clindamycin.
However, recently there have been reports of antibiotic resistance in P. Phages Electron micrograph of one type of filamentous phages that can infect P.
From Marie-Christine Chopin et al. Until recently only Ff-related phages were known to be active in Gram-positive bacteria; however, at least five phages with filamentous morphology were shown to be active in P. Filamentous phages, which are rod-shaped and contain circular single-stranded DNA about 10 genesgenerally infect Gram-negative bacteria using virion morphogenesis in which particles that do not cause lysis or cell death are secreted across the bacterial membranes continually.
The five structural proteins of a filamentous phage are as follows: Two other proteins generally found in this type of phage pI and pIV are required for phage assembly and export. One of the filamentous phages that has been found to infect P. This phage does not contain a protein similar to pIV, which specifically assists in the outer membrane phage-conducting channel.
This is probably due to the fact that since this phage infects Gram-positive bacteria, which have no outer membranes, the protein is not needed.bacteria species and particles share the same morphology. Therefore besides their shape, it is also essential to consider the color as to improve the discrimination precision .
Bacterial Morphology • Cocci – spherical / oval shaped major groups • Bacilli – rod shaped • Vibrios – comma shaped • Spirilla – rigid spiral forms • Spirochetes – flexible spiral forms • Actinomycetes – branching filamentous bacteria • Mycoplasmas – lack cell wall.
However, colony morphology is not a reliable way to identify bacteria, as many different types of bacteria have similar colony morphology. Being able to visibly differentiate bacteria based on the appearance of their colonies is a crude, but essential first step in isolating the different types of bacteria in the sample.
about the bacteria other than morphology and arrangement. The Gram stain is a differential stain commonly used in the microbiology laboratory that differentiates bacteria on the basis of their cell wall. The cell wall of gram positive bacteria contains teichoic acid while that of gram negative bacteria does not.
The gram negative cell wall contains lipopolysaccharide which . Bacteria are the ubiquitous microscopic organisms that are not visible with the naked eye. Bacterial morphology (size, shape and arrangement of bacterial cells) is one of the mostly used feature for the differentiation of various bacterial species.