G-IVE COCCI Flashcards
neisseria is consists of ___ species
kingella
eikenella
simonsiella
alysiella
moraxellaceae family includes
moraxella catarrhalis
Obligate anaerobe, non-motile and non-haemolytic
Fastidious, capnophilic and grow optimally in a moist temperature
Carbohydrate fermenters
Sensitive to heat and drying
neisseria
neisseria grows best in media with
blood and cholesterol
nesseria with non-pigmented colonies
N. flava, N. flavescens, and N. subflava
neisseria shape
G-ve diplocci (coffee or kidney bean shaped)
rod shaped neisseria
N. elongate, N. bacilliformis and N. weaver
neisseria culture the colonies appear,
small, grayish-white, opaque, convex and glistening.
neisseria human pathogens
N. gonorrhoea and N. meningitidis
most important factor in the lab.diagnosis of Neisseria gonorrhoea
Specimen collection and handling
swabs (neisseria) should be placed in a transport media of ______ and ____ within __ hours
amies medium with charcoal and plate within 6 hours
N. gonorrhoea will not be recovered in blood culture because of
sodium polyanethole sulfonate.
general biochemical tests for neisseria
carbon utilization test
oxidase test
superoxol test
dnase test
- standard method of identifying N. gonorrhoea
- Detects acid reduction from glucose, maltose, lactose, fructose and sucrose
carbohydrate utilization test
carbohydrate utilization test reagent
Cystine trypticase agar (CTA) with 1% carbohydrate
carbohydrate utilization pH indicator
phenol red
carbohydrate utilization test positive result
yellow color within 24 to 72 hours incubation
reagent in oxidase test
1% tetramethyl-p-phenylenediamine dihydrochloride
oxidase test (+) result
purple color within 10 seconds
reagent in superoxol test
20% to 30% H202 (hydrogen peroxide)
(+) result in oxidase test
vigorous bubbling
dnase test culture medium
Culture medium is Dnase agar with methyl green
dnase test (+) result
clear halo around the colonies after 18 to 24 hours incubation
in dnase test, M. catarhhalis and Neisseria gives opposite reaction where
Moraxella catarrhalis secretes Dnase which signifies positive reaction while Neisseria gives a negative reaction
Not a human microbiota but only humans are the only known host.
Leading cause of sexually transmitted diseases
Can be transmitted by an infected mother to a newborn during birth
Glucose fermenters
Neisseria gonorrhoea (Gonococcus)
Neisseria gonorrhoea (Gonococcus) is found in
Found in the urogenital tract, anorectal area, oropharynx and conjunctiva
principal virulence factor of N. gonorrhoea is
Principal virulence factor is the common pili
N. gonorrhoea culture
CAP – colonies appear small, tan-colored, translucent, and raised.
related infections and disease to n. gonorrhoea
Gonorrhea
Purulent urethritis (males) and cervicitis (females)
Pharyngitis
Anorectal Infections (rectal gonorrhoea)
Conjunctivitis (ophthalmia neonatorum)
Purulent arthritis
- greek words gonos, wich means “seed” and rhoia, which means flux
-acute pyogenic infection of non-ciliated, columnar, and transitional epithelium
Gonorrhea
gonorrhea maybe asymptomatic among females but if with symptoms it may include..
Symptoms may include purulent discharge, lower abdominal pain for men, and vaginal bleeding for woman.
gonorrhea maybe asymptomatic among females but if with symptoms it may include..
Symptoms may include purulent discharge, lower abdominal pain for men, and vaginal bleeding for woman.
Untreated gonococcal cervicitis may cause
sterility and perihepatitis (Fitz- Hugh-Curtis syndrome)
the chief complaint in symptomatic oropharyngeal infections
pharyngitis
causes rectal pain and a bloody stool.
Anorectal infections (rectal gonorrhoea)
a gonococcal eye infection acquired by newborns during normal delivery through an infected birth canal
conjunctivitis (ophthalmia neonatorum)
n. gonorrhoea specimens are collected from the pus secretions from Pus secretions
Pus secretions from the urethra, cervix, prostate, rectal mucosa, throat, and joint fluid
Laboratory diagnosis
- Gram Stain
- Culture (for confirmation)
- Immunologic test
- Molecular assays
- Antimicrobial susceptibilty test
in gram stain, neisseria is intracellular Gram-negative diplococci, coffee-or kidney bean-shaped and smears should be prepared from
urogenital specimens not from pharyngeal specimens
Direct inoculation at the bedside is optimal and N.gonorrhoea does not grow on ___
blood agar plate (BAP)
N. gonorrhoea and N. meningitidis require immediate incubation after plating at ____ degree cent.for ___ hours at ___ incubator or ____ and ____ system.
35 to 37; 72; CO2; candle jar and JEMBEC
Chocolate agar with an enrichment supplement IsoVitaleX and antibiotics
Antimicrobial agents are vancomycin, colistin, and nystatin
N.meningitidis, N. lactamica, and N. flavescens
TMA
It has all TMA components and trimethoprim lactate
MTMA
- It contains all MTM agar components except nystatin which is substituted by anisomycin
- It has an increased vancomycin concentration
ML Medium
- It is a transparent medium with lysed horse blood and yeast dialysate
- It contains all MTM components and amphotericin B
- It can also grow genital mycoplasma ( Mycoplasma hominis and Ureaplasma urealyticum)
NYC medium
It contains the same NYC antibiotics and lincomycin
GC - LECT Medium
transport media
Transgrow, Cary Blair, Amies and JEMBEC (John E Martin Biological Environmental Chamber) system.
- It employs monoclonal antibodies for bacterial identification
- It does not require pure or viable organisms and can be performed on primary plates
immunologic test
- this test is highly specific and sensitive
-Uses monoclonal antibodies that recognize epitopes on the principal outer membrane protein of N. gonorrhoea
Fluorescent antibody test (FAT)
- Uses monoclonal antibodies to identify the gonococci
(+) result : Exhibits agglutination
Coagglutination
detects gonococcal antigen or nucleic acid directly in specimens
- Has the capability to detect Chlamydia trachomatis.
Nucleic acid amplification test
specimens of Nucleic acid amplification test
Specimens: endocervical or urethral swabs and urine
rapid test for directly detecting gonococcal rRNA in genital and conjunctival specimens and which provides results within hours.
Chemiluminescent nucleic acid probe
Chemiluminescent nucleic acid probe specimen
Endocervical or urethral swabs
Chemiluminescent nucleic acid probe is not recommended for ____ specimens
Not recommended for pharyngeal or rectal specimens
preffered medium in Antimicrobial susceptibility test (AST)
GC agar
preferred method in .Antimicrobial susceptibility test (AST)
Disk diffusion or agar dilution
alternative method for Antimicrobial susceptibility test (AST)
E-test
Antimicrobial susceptibility test (AST) utilizes antibiotics such as
extended-spectrum cephalosporins and quinolones
- Causative agent of meningococcemia or spotted fever
- Leading cause of fatal bacterial meningitis
- Commensal of the URT
- Glucose and maltose fermenter, requires iron for growth
- β-lactamase test: Positive
Neisseria meningitidis ( Meningococci)
Neisseria meningitidis ( Meningococci) is found in
nasopharynx and oropharynx
Neisseria meningitidis ( Meningococci) culture
Encapsulated strains are mucoid in appearance. Colonies appear bluish gray on BAP.
small, tan, and mucoid on CAP
Neisseria meningitidis ( Meningococci) serogroups
A, B, C, Y, and W-135
Neisseria meningitidis ( Meningococci) virulence factors
Pili, polysaccharide capsules, cellular membranes (pro A and B)
related infection to n. meningitidis
meningococcemia
- It refers to the presence of N. meningitidis in the blood, occur in acute or chronic form
- Occurs with or without meningitis
- Source of epidemics are oral secretions and respiratory droplets
meningococcemia
meningococcemia signs and symptoms
frontal headache, stiff neck, and fever.
Petechial skin lesions may develop during bacteremic spread due to
release of endotoxin after a bacterial cell lysis
meningococcemia drug of choice
penicillin
specimens of N. meningitidis
CSF, blood, nasopharyngeal swabs, and petechial skin lesions
laboratory diagnosis of N. meningitidis
- Gram Stain
- Culture
- Oxidase Test
- Antimicrobial Test
- Immunologic Test
- gamma-glutamyl aminopeptidase test
reveals Gram-negative intracellular and extracellular diplococci
gram stain (n.meningitidis)
(n.meningitidis) culture media
Media are BAP, CAP and TMA
nasopharyngeal swabs (n.meningitidis) should be placed in the
JEMBEC system
N. meningitidis is sensitive to ____, so the content in blood culture broth should not exceed to ____
SPS ; 0.025%
oxidase test of n.meningitidis positive result
purple color
in antimicrobial test (n.meningitidis) the ff. are utilized:
- broth microdilution or agar dilution MIC test with cation-supplemented MH broth
- Laked horse blood or MHA with 5% sheep blood
- Penicillin G as primary treatment
direct identification of antigens in CSF, serum, and urine
Latex agglutination-
accelerates antibody and antigen through a buffered diffusion medium
Counterimmunoelectrophoresis
N. meningitidis produces this enzyme
γ-glutamyl aminopeptidase test
Non-pathogenic Neisseria Species
- Neisseria cinerea
- Neisseria flavescens
- Neisseria mucosa
- Neisseria lactamica
- Neisseria sicca
- Neisseria elongata
- Neisseria weaveri
- Colonies on CAP is similar to the T3 colonies of N. gonorrhoea
-Colistin susceptibility test differentiates N. cinerea from N. gonorrhoea - Grows on MH but not on TMA
N. cinerea
- Asaccharolytic, yellow pigmented Neisseria species
- Ability to grow on BAP and CAP at 22 degree centigrade
N. flavescens
Usually isolated from nasopharynx of children or young adults
- Grow in NA incubated at 22 degree centigrade
- Colonies appear large and very mucoid
N. mucosa
Isolated from meningococcal carrier surveys, commonly in children who are two years of age and rarely from adults
N. lactamica
- it will grow in NA incubated at 25 degree centigrade
- Colonies appear like bread crumbs
N. sicca
- it is a “ rod-shaped” gram-negative coccus
- weakly positive or negative catalase test
N. elongata
- it is a “ rod-shaped” gram-negative coccus
- Positive catalase test but does not produce acid from any of the carbohydrates that are used to identify Neisseria species.
N. weaveri
- Most commonly isolated member of the genus Moraxella
- Part of the microbiota of the oropharynx and is an opportunistic pathogen
- Resembles Neisseria species by exhibiting Gram-negative coccal morphology
- Non-motile, fastidious, β-lactamase producer and is encapsulated with common pili
- Causes URT infections in otherwise healthy children and the elderly
- Third most common cause of otitis media and sinusitis in children
Moraxella catarrhalis (Branhamella catarrhalis)
under the microscope, Moraxella catarrhalis (Branhamella catarrhalis) is..
Small, gram-negative cocci that tends to grow in pairs and have a “ hockey puck” appearance
M. catarrhalis lab. diagnosis
- Gram stain- presence of intracellular diplococci
- Culture : BAP and CAP
- Catalase and oxidase tests
- CHO utilization test
- DNase test
- Butyrate esterase/Tributyrin test
M. catarrhalis in gram staining
presence of intracellular diplococci
m. catarrhalis culture
BAP AND CAP
m. catarrhalis growth on BAP at ___ degree centigrade
22
m. catarrhalis growth on nutrient agar at __ degree centigrade
35
m. catarrhalis inhibit in a ___ medium by ___
gonococcal medium ; colistin
m. catarrhalis is catalase and oxidase test ___
positive
M. catarrhalis does not utilize any sugar in ____
CTA
CHO utilization test of M. catarrhalis (-) result
No fermentation of sugar
definitive test for M. catarrhalis
Dnase test and butyrate esterase/tributyrin test
M. catarrhalis dnase test (+) result
Exhibits a clear or colorless halo around the colonies after 24 hours incubation.
substrade in butyrate esterase/tributyrin test (m. catarrhalis)
Substrate is a bromo-chloro-indolyl butyrate
m. catarrhalis Butyrate esterase/Tributyrin test (+) result
blue color