Peptococcus

Peptococcus presentation

1. Peptococcus 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 INTRODUCTION

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. INTRODUCTION contd..

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

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 W ilkins 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 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. Cultural characterstics

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 Biochemical characterstics

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. Pathogenecity

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 Laboratory diagnosis

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). Treatment

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