microbiology, bailey_s and scotts chapter 28, moraxella and related orgs. by mt1232
TRANSCRIPT
-
8/10/2019 Microbiology, Bailey_s and Scotts Chapter 28, Moraxella and Related Orgs. by MT1232
1/3
-
8/10/2019 Microbiology, Bailey_s and Scotts Chapter 28, Moraxella and Related Orgs. by MT1232
2/3
Neisseria elong ata (all subspecies)
o BAP- Gray, transluscent, smooth, glistening;
may have dry, claylike consistency
o Mac- non-lactose fermenter, if there is
growth
N. weaverii
o BAP- Small, smooth, semi opaque
o Mac- Mac- non-lactose fermenter, if there is
growth
Appro ach to ident i ficat ion
These organisms can be difficult to differentiate from
gram-negative diplococci
Relatively biochemically inert
Elongation in the presence of penicillin- used to
differentiate them from true cocci
Penic i l l in
Streaking on BAP, placing a 10-unit penicillin disk at
the first quadrant
Incubation- 35C Gram stain of the growth taken from around the edge
of the zone of inhibition determines whether the
organism is a true cocci or has elongated
Additional notes
Two most frequently isolated species:
M. nonl iquefaciens
M. osloensis
M. osloensis-utilizes acetate
M. lacun ata- able to liquefy serum (depressions are
formed on the surface of Loefflers serum agar slants
Most species do not utilize glucose Neisseria elong ata subsp.Glycolyt ica- produces
acid from glucose in the rapid test used for Neisseria
spp.; is the only exception
None of the organisms considered are motile
(unlike Oligellaspp)
Serodiagnosis
not generally used for the laboratory diagnosis of
infections caused by the organisms
Prevent ion
Organisms do not usually pose a threat to human
health No recommended vaccination or prophylaxis
protocols
Organism Medium Appearance
Moraxella atlantae BAP Small, pitting andspreading
Mac NLFM. lacunata BAP Small colonies that pit
the agar
Mac No growth
M. l incoln i i BAP Smooth, transluscent tosemi opaque
Mac No growth
M. nonl iquefaciens BAP Smooth, transluscent tosemi opaque,occasionally,coloniesspread and pit agar
Mac NLF, if growthM. osloensis BAP Smooth, transluscent to
semi opaque
Mac NLF, if growthM. canis BAP Resemble colonies of
enterobacteriaceae
Mac NLFNeisseria elong ate
(all subsp ecies)
BAP Gray, transluscent,smooth, glistening; mayhave dry, claylike
consistencyMac NLF, if growth
N. weaverii BAP Small, smooth, semiopaque
Mac NLF, if growth
Note: BAP = Sheep Blood Agar, NLF = Non-Lactose
Fermenter and MAC = Mac Conkey Agar.
EPIDEMIOLOGY, PATHOGENESIS AND SPECTRUM OF DISEASE
Organism Habitat(Reservoir ) Mode of
Transmission
Virulence Factors Spectrum of Disease and
Infect ions
Moraxella :
nonliquefaciens
lacunata
osloensis
lincolnii
canis
atlantae
Normal human flora thatinhabit mucousmembranes covering thenose, throat, other partsof the upper respiratorytract, conjunctiva and forsome species (i.e. M.osloensis, the urogenitaltract may also colonizethe skin).
Infections are rare:when they occur,they are probablycaused by thepatientssendogenousstrains: person-to-persontransmission maybe possible, butthis has not been
Unkown, becausethey are rarelyassociated withinfections they areconsideredopportunisticorganisms of lowvirulence.
M. lacunata has historicallybeen associated with eyeinfections but theseinfections also may becaused by other Moraxellaspp: other infections includebacterimia, endocarditis,septic arthritis and possiblyrespiratory infections
-
8/10/2019 Microbiology, Bailey_s and Scotts Chapter 28, Moraxella and Related Orgs. by MT1232
3/3
documented.
Neisseria elongate Normal flora of upperrespiratory tract.
When infectionsoccure, they areprobably caused bythe patientsendogenous strain.
Unknown; anopportunisticorganism of lowvirulence
Rarely implicated ininfections ; has beendocumented as a cause ofbacteremia, endocarditisand osteomyelitis.
Neisseria weaverii Oral flora of dogs Dog bite Unknown Infections of dog bitewound.
Ant imic robial Therapy and Suscept ib i l i ty Test ing
Organism Therapeutic Options Potential Resistance toTherapeutic Options
Validated Testing Methods
Moraxella spp. No definitive guidelines ;generally susceptible to
penicillins andcephalosporins
Beta-Lactamase-mediatedresistance to penicillins common
Not availableException: See CLSI documentM45 for testing guidelines for M.
catarrhalis at chapter 40Neisseria elongate and
Neisseria weaveriiNo definitive guidelines;generally susceptible to
penicillins andcephalosporins.
None known Not available.
Biochem ical Key and Physiolog ic Character is t ics
OrganismGrowth
onMAC
CatalaseNO3
ReductionNO2
ReductionDNAse
DigestsLoeffers
Slant
SodiumAcetate
Utilization
Growth inNutrient
Broth
M. atlantae + + - - - - ND -
M. lacunata - + + - - + - -
M. lincolnii - + - - - - - -
M.nonliquefaciens
-+ +
- -- -
V
M. osloensis V + V - - - + +
M. canis + + + V + - + +
N. elongata subspelongata
V - - + ND ND V +
N. elongata subspglycolytica
+ + - V ND ND + +
N. elongata subspnitroreducens
V - + + ND ND V V
N. weaverii V + - + ND ND - V
Legend:
ND= No Data
V = variable
+ = 90 percent of strains are positive
Note: Organisms are generally indolenegative.