GRAM POSITIVE NON-SPORE FORMING BACTERIA

Prepared by:Miss Norzawani Jaffar & Mr Norazli Ghadin

Bsc (Hons) Biomedical Sciences, UKM

• Student could list the name of Gram +ve Nonspore forming bacteria

• Student could classified the group of bacteria in the topic.

• Student could discuss common identification characreristic of each genus.

• Student could able to relate the bacteria with disease.

Learning Outcome

Gram Positive Bacteria

• Gram-positive bacteria, stained purple, of both the bacillus (“rod-shaped”) and coccus (spherical) forms.

• Gram-positive bacteria are those that are stained dark blue or violet by Gram staining.

• This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain (safranin or fuchsine) and appearing red or pink.

• Gram-positive organisms are able to retain the crystal violet stain because of the high amount of peptidoglycan in the cell wall.

• Gram-positive cell walls typically lack the outer membrane found in Gram-negative bacteria.

GRAM POSITIVE NONSPORE-FORMING BACILLI (Genus)

a) Regular, aerobic.a) Lactobacillusb) Listeriac) Erysipelothrixd) Rhotiae) Arcanobacterium

b) Irregulara) Aerobe Corynebacteriumb) Anaerobic

a) Propionibacteriumb) Bifidobacteriumc) Eubacterium

Regular, aerobic

• Lactobacillus sp.• Catalase negative, nonmotile, nitrate reducer,

glucose fermenter.• Normal flora at vagina, intestinal tract and oral cavity• Use for commercial industry

Regular, aerobic

• Listeria sp 6 species.• L. monocytogenes cause Listeriosis (high fatality)• Suspected in immunocompromise patient• Noncapsulated, motile, catalase +ve, D-glucose

fermenter, beta hemolitic, API LISTERIA®

Regular, aerobic

Erysipelothrix• Erysipelothrichaceae (Verbarg et al., 2004), is Gram-

positive but may appear Gram negative• Strains are nonencapsulated, nonsporulating, nonmotile,

straight, or slightly curved, slender rods with rounded ends, some show a tendency to form long filaments. Organisms are arranged singly, in short chains, or in pairs in a “V” configuration or are grouped randomly.

• optimal temperature 30–37°C, pH of 7.2–7.6• a facultative anaerobe. Growth is improved by 5–10%

carbon dioxide. Heating at 60 °C for 15 min is lethal.

• Erysipelothrix rhusiopathiae is able to grow in the presence of 0.2% phenol, 0.1% ,sodium azide, 0.001% crystal violet, 0.05% potassium tellurite, 0.02% thallous acetate, and 0.2% 2,3,5, triphenyl-tetrazolium chloride

• catalase- negative and oxidase negative. • anaerobic, chemoorganotrophic with respiratory

metabolism, and weakly fermentative. • Acid but no gas produced from glucose and other

carbohydrate• Erysipelothrix rhusiopathiae : in a mild cutaneous form

known as erysipeloid

Regular, aerobic

Regular, aerobic

Rhotia• Identification with combination

morphological and biochemical tests used for staphylococci and micrococci

• nonmotile and spherical, cluster arranged. • Copious capsule• Oxidase and benzidine tests are negative• The catalase reaction is negative in 50%• Resistant to lysostaphin

• Sugars is fermented anaerobically (acid but no gas) • Usual identification is combination of commercial

identification systems, conventional biochemical tests and combined with adherence to agar surfaces, poor growth on Mueller-Hinton agar, and the presence of a capsule

• Cause infection in patients with endocarditis, intravenous drug abuser, in patients with pre-existing valvular heart disease, and recurrent peritonitis during chronic ambulatory peritoneal dialysis

Regular, aerobic

Regular, aerobic

Arcanobacterium

•facultative anaerobic, •catalase negative, •rods (coccal shape old culture) occurs as the organism grows) with arrangements described as matchbox or Chinese letters arrangements. •Growth is enhanced in blood and by carbon dioxide.

•Cause pharyingitis, sepsis and osteomyelitis•Sensitive to erythromycin(proposed as the first line drug), clindamycin, gentamicin, and cephalosporins.

irregular, aerobic

Corynebacterium•catalase positive, •non-spore-forming, •non-motile, •rod-shaped bacteria that are straight or slightly curved.•Have metachromatic granules • size falls between 2-6 umX 0.5 um. •The bacteria group together "V", "palisades", or "Chinese letters". •They are aerobic or facultatively anaerobic, chemoorganotrophs, with a 51–65% genomic G:C content. •They are pleomorphic through their life cycle

irregular, aerobic

Cause diphtheria (C. diphtheriae).Occur in •unvaccinated individuals, •those in developing countries,elderly, •neutropenic or immunocompromised patients, and those with•prosthetic devices •infect wounds, the vulva, the conjunctiva, and the middle ear. •It can be spread within a hospital•Other pathogenic species in humans include: C. amicolatum, C. striatum, C. jeikeium, C. urealyticum, and C. xerosis

irregular, anaerobic

Propionibacterium• P. acnes cause acne • slow growing, • Aerotolerant • can also cause chronic blepharitis and

endophthalmitis, • Commensal (skin ,gastrointestinal tract )• It lives primarily on, fatty acids • ability to generate propionic acid

irregular, anaerobic

Bifidobacterium• non-motile, nonfilamentous, often

branched,pleomorphic • occur singly or in many-celled chains or clumps.• Cells have no capsule • inhabiting the gastrointestinal tract, vagina] and

mouth (B. dentium). • Bifidobacteria aid in digestion allergies, prevent

tumor growth[. probiotics.• G. vaginalis, which is Gram variable

irregular, anaerobic

negative for the following:• indole, gelatin hydrolysis, catalase , and

oxidase. • growth temperature is 35–39°C• from 42–67 mol%. • chemoorganotrophs (fermentative)• produce acid but no gas from a variety of

carbohydrates.

irregular, anaerobic

• Pathology• B. denticolens bacteria isolated from dental caries

(and probably involved in caries pathology) • Gardnerella vaginalis that often assumes pathogenic

character (such as in bacterial vaginosis and in urogenital tract infections of both sexes).

B.denticolens

G. vaginalis

irregular, anaerobic

Eubacterium• obligately anaerobic rods• that do not produce:

– propionic acid as major acid – lactic acid alone – more acetic acid than lactic acid with and without

formic acid – succinic acid (in the presence of carbon dioxide)

and lactic acid with small amounts of acetic or formic acid

irregular, anaerobic

Q & A

MICROBIOLOGY II: TOPIC 2

Take note from

http://norazlicucst.weebly.com