Peptococcus presentation

1. BY-SANJU SAH
ST. XAVIER’S COLLEGE, MAITIGHAR,KATHMANDU
DEPARTMENT OF MICROBIOLOGY

2.  Domain:Bacteria
 Phylum:Firmicutes
 Class:Clostridia
 Order:Clostridiales
 Family:Peptococcaceae
 Genus:Peptococcus

3.  Peptococcus is a Gram-positive anaerobic cooci
(GPAC) in the family Peptococcaceae.
 Species in the genus are part of the human
microbiome, especially in the bacteria that form
the gut flora.
 They are part of the flora of the mouth, upper
respiratory tract and large intestine.
 They are found to cause soft tissue infection and
bacterimias.
 Peptococcus is the genus of non motile anaerobic
chemo organotrophic bacteria containing gram
positive spheric cells that occur singly, pairs,
tetrad or irregular masses rarely in short chains.

4.  Peptococcus niger
 Peptococcus asaccharolyticus
 Peptococcus glycinophilus
 Peptococcus indolicus
 Peptococcus magnus
 Peptococcus niger
 Peptococcus prevotii
 Peptococcus saccharolyticus

5. 1) Morphology and general characterstics
 Peptococcus niger is a gram-positive, non-motile, obligatory
anaerobic cocci that is a constituent of the normal human
intestinal mucous membranes and umbilicus flora.
 The bacterial cells are 0.3 – 1.3 μm in diameter, and can exist
singly, in pairs, tetrads, or in irregular clusters .
 other strains were isolated from human navel flora by Wilkins et
al.(1975)
 Very rarely when the organism is isolated from the pathological
specimen.
 Although it is the type species of family peptococcacae niger in
only distinctly related to others members.
 Based on the similarities and relatedness of the G+C content of the
Peptococcus and Peptostreptococcus DNA, all species previously
classified under the Peptococcus genus has been transferred to the
Peptostreptococcus genus, with the exception of Peptococcus
niger

6.  It can be cultured on enriched blood agar.
 They grow slowly to form raised circular
entire colonies 1mm in diameter after
incubation on 5 days.
 Black colonies may be seen on the initial
isolation but become grey on exposure to air,
pigment is often absent after several
laboratories transfer.

7.  The type strains forms catalase but is inactive
in other presently available tests.
 The distinctive VFA profile includes butyric,
isovaleric and terminal n-caproic acid.
 The bacterium produces H2S, NH3, and H2,
but cannot liquefy gelatine, serum, digest
milk, nor ferment carbohydrates

8.  The bacteria have been associated with ovine
foot rot, and rarely retrieved from animal
infections.
 The very slow growth rate exhibited by P. niger
and its lack of distinctive biochemical features
may be responsible for its low pathogenicity .
 As it is seldom isolated from clinical specimens
and not commonly cultured from human
pathological specimens.
 A study reported that cultured strains from a
rectal abscess, a pilonidal cyst, and a vaginal area
swab found only one strain of P. niger amongst
278 other gram-positive cocci examined.

9.  EPIDEMIOLOGY: Worldwide – P. niger is part of the normal
human umbilical and intestinal flora.
 HOST RANGE: Although uncommon, P. niger has been
isolated from the normal flora of the human umbilicus,
and in rare cases have been isolated from ovine foot rot
disease of hooved animals.
 INFECTIOUS DOSE: It is unknown for humans and other
animals. However, the infectious dose is likely to be
extremely high as P. niger is rarely isolated from human
pathogenic specimens.
 MODE OF TRANSMISSION: No disease has been specifically
linked to P. niger, and thus the route of transmission of
the bacteria is not currently known.
 INCUBATION PERIOD: Unknown
 COMMUNICABILITY: Not known to be communicable
between humans.
 RESERVOIR: Humans and hooved animals.
 ZOONOSIS: None
 VECTORS: None

10.  SOURCES/SPECIMENS: Human intestinal or
umbilical tissue, and mucous membranes.
 P. niger H4 strain can be isolated from the
human gastrointestinal tract, as well as from
the hooves of animals afflicted with ovine
foot rot

11.  DRUG SUSCEPTIBILITY: Studies have shown that
strains are susceptible to penicillin, ampicillin,
azlocillin, piperacillin, mexlocillin, metronidazole,
cefuroxime, cefoperazone, cefotaxime, imipenem,
erythromycin, clindamycin, chloramphenicol, and
tetracycline.
 DRUG RESISTANCE: Resistance to metronidazole and
lincomycin have been reported.
 SUSCEPTIBILITY TO DISINFECTANTS: Most bacteria are
susceptible to 1% sodium hypochlorite, 2%
glutaraldehyde, formaldehyde, and 70% ethyl or
isopropyl alcohol.
 PHYSICAL INACTIVATION: Inactivated by moist heat
(121°C for 15 – 30mins) and dry heat (160 - 170°C for
1-2 hours).

12.  Topley and Wilson's Microbiology and
Microbial Infections, 9th Edition, Page no:793
 Public Health Agency of Canada
 www.publichealth.gc.ca