4. GENERAL PROPERTIES
• THEY ARE FILAMENTOUS BACTERIA
• THEIR MORPHOLOGY RESEMBLES THAT OF FILAMENTOUS
FUNGI- ALSO KNOWN AS RAY FUNGI
• HIGH G+C CONTENT THAN ANY OTHER BACTERIA
• SOURCE OF MOST OF CURRENTLY USED ANTIBIOTICS ALSO
PRODUCE METABOLITES THAT ARE ANTICANCER,
ANTHELMINTHIC AND IMMUNOSUPPRESSIVE COMPLEX LIFE
CYCLE
• GRAM POSITIVE
• SAPROPHYTIC AND MAINLY ACTING AS DECOMPOSERS IN THE
SOIL
• WIDE SPECTRUM ANTIBIOTIC ARE COMMERCIALLY PRODUCED
FROM STREPTOMYCES
• INTERMEDIATE GROUP BETWEEN BACTERIAL AND FUNGI
• REPRESENTATIVE GENERA FOR THIS PRESENTATION;
STREPTOMYCES, NORCADIA,ACTINOMYCES
5. ACTINOMYCETES
• IRREGULAR, NON SPORE FORMING GRAM POSITIVE RODS ,EITHER AS AEROBIC OR AS
FACULTATIVE ANAEROBIC ISOLATES
• NOCARDIA ARE CLOSELY RELATED TO THE GENERA MYCOBACTERIUM AND
CORYNEBACTERIUM BUT DIFFER DISTINCTLY FROM ACTINOMYCES IN CELL WALL CHEMICAL
CHARACTERISTICS AND PERCENTAGES OF GUANINE AND CYTOSINE
• MYCOBACTERIUM SPECIES DIFFER BY THE PRESENCE OF RODS RATHER THAN OF FRAGMENTING
MYCELIUM, BY RELATIVELY POOR GRAM-STAINING, AND BY STRONG ACID-FASTNESS
• ACTINOMYCES- ANAEROBIC, NORMAL FLORA
• NOCARDIA- AEROBIC, SAPROPHYTES-PARTIALY ACID FAST
• STREPTOMYCES- AEROBIC, SAPROPHYTES
6. NOCARDIA AND STREPTOMYCES
● OBLIGATE AEROBIC SAPROPHYTES, FOUND IN SOIL
● A FEW SPECIES ARE RARE OPPORTUNIST PATHOGENS, CAUSING DISEASE IN CASES IN WHICH
PREDISPOSING FACTORS SUCH AS IMMUNITY OR NORMAL BODY DEFENSE MECHANISMS ARE
GROSSLY IMPAIRED
●COLONIES VARY FROM HEAPED, WAXY, AND VARIABLY PIGMENTED TO DENSE, WHITE
MYCELIAL, AND MOLD LIKE
● ALL GENERALLY GROW IN 3-5 DAYS AT 37°C AND ARE CATALASE POSITIVE.
● NOCARDIA ARE MOST COMMONLY ENCOUNTERED, BUT STREPTOMYCES MAY BE CULTURED
FROM MYCETOMAS IN TROPICAL AREAS
7. NORCADIA
• THE PATHOGENIC NOCARDIA ARE OFTEN ACID-FAST (OR PARTIALLY SO),
• GRAM-POSITIVE,
• UREASE POSITIVE
• BRANCHING FILAMENTOUS RODS THAT BREAK UP INTO BACILLARY OR COCCOID
FORMS.
• THEY ARE STRICTLY AEROBIC
• FOUND IN THE SOIL.
• THE SPECIES OF IMPORTANCE IS N. ASTEROIDS.
8. NORCADIOSIS
• BRONCHOPULMONARY
IMMUNOCOMPROMISED PATIENTS ;POTENTIAL FOR DISSEMINATION TO THE CNS
DX; PNEUMONIA WITH CAVITATION
• CUTANEOUS OR SUB CUTANEOUS LESIONS;
• CAN OCCUR IN HEALTHY INDIVIDUAL WITH TRAUMATIC INJURY LEAD T
MYCETOMAS
• PAINLESS ,SUBCUTANEOUS SINUS
9. PATHOGENICITY
NOCARDIOSIS IS USUALLY A CHRONIC, PROGRESSIVE
DISEASE CHARACTERIZED BY SUPPURATING,
GRANULOMATOUS LESIONS.
THE ORGANISM PRODUCES ACUTE AND CHRONIC MASTITIS
WITH GRANULOMATOUS LESIONS AND DRAINING SINUS
TRACTS
LOCALIZED SUBCUTANEOUS LESIONS OR LYMPH NODE
INVOLVEMENT, OR BOTH, ARE SEEN.
GENERALIZED NOCARDIOSIS CHARACTERIZED BY
PNEUMONIA AND THE ACCUMULATION OF LARGE
QUANTITIES OF RED FLUID IN THE THORACIC OR
ABDOMINAL CAVITY,
THE FLUID IN THESE CAVITIES IS SEROSANGUINOUS AND
INFREQUENTLY CONTAINS SMALL (<1 MM) SULFUR LIKE
GRANULES.
CARE MUST BE TAKEN TO DISTINGUISH ANY 'NOCARDIA'
ISOLATED FROM A. VISCOUS
10. DIRECT EXAMINATION
• GRANULES, IF PRESENT, ARE EXAMINED AS DESCRIBED EARLIER.
• GRAM-STAINED SMEARS OF PUS OR CRUSHED GRANULES REVEAL GRAM-
POSITIVE BRANCHING FILAMENTS, WITH OR WITHOUT CLUBS
• THE MODIFIED ACID-FAST STAIN OFTEN SHOWS THE RETENTION OF SOME
CARBOLFUCHSIN, BUT THIS IS NOT A RELIABLE CHARACTERISTIC OF
NOCARDIA.
• PUS CONTAINING THE CHARACTERISTIC ELEMENTS IS INOCULATED ONTO
SEVERAL BLOOD SLANTS OR PLATES AND SABOURAUD DEXTROSE AGAR
WITHOUT INHIBITORS. INCUBATE AT ROOM TEMPERATURE AND AT 37°C
FOR UP TO A WEEK.
11. CULTURAL CHARACTERISTICS
• GROWTH IS EVIDENT IN 4-5 DAYS, AND COLONIES ARE IRREGULARLY FOLDED, RAISED, AND
SMOOTH OR GRANULAR.
• THE COLOR VARIES FORM WHITE THROUGH YELLOW TO DEEP ORANGE.
• GRAM-POSITIVE, PARTIALLY ACID-FAST MYCELIAL FILAMENTS, WHICH BREAK UP INTO BACILLARY
FORMS, ARE EVIDENT UNDER OIL IMMERSION.
• THE PRESENCE OF MYCELIAL ELEMENTS DISTINGUISHES NOCARDIA
• FROM SAPROPHYTIC AND ATYPICAL MYCOBACTERIA. THE MYCELIAL FORMS OF THE NOCARDIA CAN
BE READILY SEEN IN SLIDE CULTURES ON SABOURAUD DEXTROSE AGAR. THE SPECIES GROWS WELL
AT 45°C.
• IDENTIFICATION; A HIGHLY PRESUMPTIVE IDENTIFICATION OF N. ASTEROIDES INFECTION IS BASED
ON PATHOLOGY, DEMONSTRATION OF TYPICAL ORGANISMS, AND COLONIAL, CULTURAL, AND
MORPHOLOGICAL CHARACTERISTICS.
12. ANTIBIOTIC SUSCEPTIBILITY
• BROTH MICRODILUTION METHOD IS RECOMMENDED BY THE CLSI FOR
ANTIMICROBIAL SUSCEPTIBILITY TESTING FOR NOCARDIA SPP
• A STUDY OF IN VITRO SUSCEPTIBILITY HAS SHOWN THAT ALL N. ASTEROIDES
TESTED WERE SENSITIVE TO SULFIXAZOLE, TRIMETHOPRIM-SULFAMETHAZOLE,
DOXYCYCLINE, AND MINOCYCLINE AND MOST TO AMPICILLIN; ABOUT HALF
WERE RESISTANT TO TETRACYCLINE
13. ACTINOMYCES
• ARE GRAM-POSITIVE, DIPHTHEROIDAL OR BRANCHING FILAMENTOUS RODS, 0.2-1.0 ΜΠΊ IN
DIAMETER.
• SHORT RODS, WHICH MAY SHOW CLUBBED ENDS, ARE COMMON AND MAY OCCUR SINGLY,
IN DIPHTHEROIDAL PAIRS, IN SHORT CHAINS, OR IN CLUSTERS. ACTINOMYCES PYOGENES
ARE COMMONLY COCCOBACILLARY IN AN AEROBIC ATMOSPHERE.
• ACTINOMYCES ARE FACULTATIVE ANAEROBIC, WITH MOST SPECIES BEING PREFERENTIALLY
ANAEROBIC ALTHOUGH SOME SPECIES GROW WELL IN AIR; 10% C02 IMPROVES GROWTH OF
AERO TOLERANT SPECIES AND IS REQUIRED FOR AERO TOLERANT STRAINS OF
PREFERENTIALLY ANAEROBIC SPECIES
• ACTINOMYCES ARE THUS FERMENTATIVE IN METABOLISM WHEREAS NOCARDIA ARE
OXIDATIVE.
• COLONIES MAY BE EITHER ROUGH AND DRY OR SOFT AND MUCOID, WITH TRANSITIONAL
FORMS BEING COMMON.
• ACTINOMYCES CAUSE CHRONIC INFECTIONS OF SOFT AND HARD TISSUES, OFTEN WITH THE
FORMATION OF SULFUR GRANULES.
14. ACTINOMYCOSIS
• THE PRESENCE OF SULFUR GRANULES, WHILE STRIKING, IS NOT
DIAGNOSTIC OF ACTINOMYCES INFECTIONS BUT ALSO OCCURS IN
NOCARDIA OR STREPTOMYCES INFECTIONS.
• ACTINOMYCES INFECTIONS ARE OFTEN ASSOCIATED WITH THE PRESENCE
OF FOREIGN BODIES USUALLY DISRUPTED BY TRAUMA OR SURGERY OR
DENTISTRY OR OTHER INFECTION
• INFECTION IS ENDOGENOUS
• CERVICOFACIAL;
• ‘’LUMPY JAW’’ ASSOCIATED WITH RECENT DENTAL WORK, JAW TRAUMA,
POOR ORAL HYGIENE
• ‘’ SULFUR GRANULES’’
15. Gram Stain and Macroscopic Colonies
of Actinomyces
NOTE: Molar tooth appearance of
colonies on agar can help remind us that
the oral cavity is a common niche for
Actinomyces.
17. ACTINOMYCOSIS
• PELVIC; ASSOCIATED WITH PLACEMENT OF IUDS
• CNS; NOT COMMON; PRESENTS AS SOLITARY BRAIN ABSCESS
TREATMENTS, PREVENTION AND CONTROL
1. DRAINAGE OF ABSCESS/DEBRIDEMENT
2.PROLONGED PENICILLIN TREATMENT .OTHERS ARE
CLINDAMYCIN,CARBAPENEMS.
18. STREPTOMYCES
• THE LARGEST GENUS OF ACTINOBACTERIA AND THE TYPE GENUS OF THE FAMILY
STREPTOMYCETACEAE.
• OVER 500 SPECIES OF STREPTOMYCES BACTERIA HAVE BEEN DESCRIBED.[
• FOUND PREDOMINANTLY IN SOIL AND DECAYING VEGETATION,
• MOST STREPTOMYCETES PRODUCE SPORES, AND ARE NOTED FOR THEIR DISTINCT
"EARTHY" ODOR THAT RESULTS FROM PRODUCTION OF A VOLATILE METABOLITE,
GEOSMIN.
• STREPTOMYCETES ARE CHARACTERIZED BY A COMPLEX SECONDARY METABOLISM.
THEY PRODUCE OVER TWO-THIRDS OF THE CLINICALLY USEFUL ANTIBIOTICS OF
NATURAL ORIGIN (E.G., NEOMYCIN, CYPEMYCIN, GRISEMYCIN, BOTTROMYCINS AND
CHLORAMPHENICOL).
19. STREPTOMYCES
• THE ANTIBIOTIC STREPTOMYCIN TAKES ITS NAME DIRECTLY FROM
STREPTOMYCES. STREPTOMYCES'S ARE INFREQUENT PATHOGENS, THOUGH
INFECTIONS IN HUMANS, SUCH AS MYCETOMAS, CAN BE CAUSED BY S.
SOMALIENSIS AND S. SUDANENSIS, AND IN PLANTS CAN BE CAUSED BY S.
CAVISCABIES, S. ACIDISCABIES, S. TURGIDISCABIES AND S. SCABIES.
20. STREPTOMYCES IN MEDICINE
• STREPTOMYCES IS THE LARGEST ANTIBIOTIC-PRODUCING GENUS,
PRODUCING ANTIBACTERIAL, ANTIFUNGAL, AND ANTIPARASITIC DRUGS,
AND ALSO A WIDE RANGE OF OTHER BIOACTIVE COMPOUNDS, SUCH AS
IMMUNOSUPPRESSANTS.
• ALMOST ALL OF THE BIOACTIVE COMPOUNDS PRODUCED BY
STREPTOMYCES ARE INITIATED DURING THE TIME COINCIDING WITH THE
AERIAL HYPHAL FORMATION FROM THE SUBSTRATE MYCELIUM.
• STREPTOMYCETES PRODUCE NUMEROUS ANTIFUNGAL COMPOUNDS OF
MEDICINAL IMPORTANCE, INCLUDING NYSTATIN (FROM S. NOURSEI),
AMPHOTERICIN B (FROM S. NODOSUS),AND NATAMYCIN (FROM S.
NATALENSIS).
• CLAVULANIC ACID (FROM S. CLAVULIGERUS) IS A DRUG USED IN
COMBINATION WITH SOME ANTIBIOTICS (LIKE AMOXICILLIN) TO BLOCK
AND/OR WEAKEN SOME BACTERIAL-RESISTANCE MECHANISMS BY
IRREVERSIBLE BETA-LACTAMASE INHIBITION. NOVEL ANTIINFECTIVES
CURRENTLY BEING DEVELOPED INCLUDE GUADINOMINE (FROM
STREPTOMYCES SP. K01-0509), A COMPOUND THAT BLOCKS THE TYPE III
21. • MEMBERS OF THE GENUS STREPTOMYCES ARE THE SOURCE FOR NUMEROUS
ANTIBACTERIAL, ANTIPARASITIC ANTICANCER ETC. PHARMACEUTICAL AGENTS;
• CHLORAMPHENICOL (FROM S. VENEZUELAE),DAPTOMYCIN (FROM
S.ROSEOSPORUS),FOSFOMYCIN (FROM S. FRADIAE),LINCOMYCIN (FROM S.
LINCOLNENSIS),NEOMYCIN (FROM S. FRADIAE)
• S. AVERMITILIS IS RESPONSIBLE FOR THE PRODUCTION OF ONE OF THE MOST
WIDELY EMPLOYED DRUGS AGAINST NEMATODE AND ARTHROPOD INFESTATIONS,
IVERMECTIN.
• LESS COMMONLY, STREPTOMYCETES PRODUCE COMPOUNDS USED IN OTHER
MEDICAL TREATMENTS: MIGRASTATIN (FROM S. PLATENSIS) AND BLEOMYCIN
(FROM S. VERTICILLUS) ARE ANTINEOPLASTIC (ANTICANCER) DRUGS; BOROMYCIN
(FROM S. ANTIBIOTICUS) EXHIBITS ANTIVIRAL ACTIVITY AGAINST THE HIV-1
STRAIN OF HIV, AS WELL AS ANTIBACTERIAL ACTIVITY. STAUROSPORINE (FROM
S.STAUROSPOREUS) ALSO HAS A RANGE OF ACTIVITIES FROM ANTIFUNGAL TO
ANTINEOPLASTIC (VIA THE INHIBITION OF PROTEIN KINASES).
• S. HYGROSCOPICUS AND S. VIRIDOCHROMOGENES PRODUCE THE NATURAL
HERBICIDE BIALAPHOS
STREPTOMYCES IN MEDICINE …..
