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Neisseria, kingella, eikenella, simonsiella, alysiella
Neisseriaceae includes several genera such as
Moraxella catarrhalis
though once classified with neisseria, now belongs to the family moraxellaceae, along with other moraxella species and acinetobacter. it is clinically significant as a respiratory pathogen
diplococci
most members of the neisseria genus are?
Neisseria elongata, Neisseria weaver, Neisseria Bacillifornis
most members of the neisseria genus in rod shaped form are?
oxidase positive and Catalase positive
Most species are _____ and _____ , aiding in preliminary identification.
Neisseria Elongata and Neisseria bacilliformis
Exceptions, as they are oxidase and catalase negative
Biochemical characteristics
Many Neisseria species are capnophilic, requiring elevated CO₂ levels for optimal growth. They thrive in humid environments, are fastidious (needing enriched media like chocolate agar), and are sensitive to environmental changes.
Neisseria species
fastidious organisms, sensitive to drying, temperature fluctuations, and nutrient deprivation. These characteristics make transport and culture in clinical settings particularly challenging.
Neisseria gonorrhoeae and Neisseria meningitidis
These pathogenic Neisseria species are iron-dependent. They require iron to survive and obtain it by binding to human transferrin, a blood plasma protein that transports iron.
Neisseria gonorrhoeae
Acquire through sexual contact
Neisseria Meningitidis
Acquire through respiratory droplets
Transferrin binding receptors
Allow the bacteria to scavenge iron from host transferrin
Capsule
Prevents phagocytosis and aids in immune evasion
Pili
Enable adhesion to epithelial and mucosal surfaces
Pili
Also contribute to twitching motility and biofirl formation
Protein 1, Protein 2, Protein 3
Outer Membrane Proteins
Protein 1 (Porin, porA, porB)
Forms pores to facilitate nutrient and waste exchange
Neisseria Meningitidis, Neisseria gonorrhoeae
porA and porB are expressed in ______ while only porB is found in _______
protein 2 (Opacity proteins, opa)
Promote tight adherence to epithelial and phagocytic cells
Phase variable
helping evade the immune system
Protein 3 (Rmp-Reduction modifiable)
Interferes with host antibody activity by binding to igG, which may prevent complement-mediated killing.
Lipopolygosaccharide
An endotoxin similar to lipopolysaccharid(LPS), but lacking the O-antigen side chain
Lipid A
component is responsible for inflammatory damage contributing to fever, sepsis, and tissue destruction
immunoglobulin A protease
Cleaves secretory IgA on mucosal surfaces, facilitating mucosal colonization and immune evasion
Neisseria gonorrhoeae
the causative agent og gonorrhea, a common sexually transmitted infection
Gonos
the term gonorrhea comes from the greek word_____ meaning flor of seed
the clap, brothel
it is also known as ______ possible derived from the french word Clapoir meaning ______
Neisseria gonorrhoeae
Causes an acute, pyogenic (pus-forming) infection of non-ciliated columnar and transitional epithelium.
urethra, endocervix, rectum, pharynx, conjunctiva, and fallopian tube.
Neisseria gonorrhoeae – Infection Sites
Neisseria gonorrhoeae
Transmitted primarily through sexual contact (vaginal, anal, oral) and vaginal birth (neonatal infection).
humans
Neisseria gonorrhoeae – Host Specificity
T1 and T2
Piliated, virulent forms
T3 to T5
Non-piliated, avirulent forms
2 to 7 days post- exposure
Incubation period(neisseria gonorrhoeae)
Neisseria gonorrhoeae Infection in Males
Acute urethritis is the most common presentation. Symptoms include purulent urethral discharge and dysuria (painful urination).
Neisseria gonorrhoeae Infection in Males
Most cases are symptomatic, with only 3–5% asymptomatic.
Neisseria gonorrhoeae Infection in Females
Symptoms include dysuria, cervical discharge, and lower abdominal pain.
Neisseria gonorrhoeae Infection in Females
Up to 50% of infections may be asymptomatic, making diagnosis and control challenging.
Neisseria gonorrhoeae Infection in Females
Pelvic Inflammatory Disease (PID)
Ectopic pregnancy
Infertility
Perihepatitis (Fitz-Hugh–Curtis syndrome) – inflammation of the liver capsule with violin string adhesions
Anorectal and Oropharyngeal
More prevalent in men who have sex with men, but can occur in any sexually active individual
Anorectal and Oropharyngeal
Often asymptomatic or present with non-specific symptom(rectal pain with discharge)
Opthalmia Neonatorum
Neonatal conjunctivitis acquired during vaginal delivery through an infected birth canal
Opthalmia Neonatorum
Can lead to blindness if not treated promptly
1% silver nitrate(crede’s method)
prevention for neonotarum previously
Erythromycin, neomycin, or chloramphenicol ointments
prevention for neonotarum Currently
Urethra
Neisseria gonorrhoeae – Specimen Collection Men
Endocervix
Neisseria gonorrhoeae – Specimen Collection Women
Rectum, pharynx, joint fluid
Neisseria gonorrhoeae – Specimen Collection Other sites
Cotton and calcium alginate swabs
inhibitory to Neisseria gonorrhoeae
Dacron or Rayon swabs
Cotton and calcium alginate swabs examples?
JEMBEC, Gono-pak, Transgrow, Amies medium with charcoal
Neisseria gonorrhoeae – Transport Media
Neisseria gonorrhoeae
Not recommended for pharyngeal specimens due to similar-looking normal flora.
Neisseria gonorrhoeae
Gram stain shows:
Gram-negative intracellular diplococci within polymorphonuclear leukocytes
Neisseria gonorrhoeae
Does not grow on Blood sheep agar
Chocolate or Selective agar
preffered agar for neisseria gonorrhoeae
Modified thayer martin, martin lewis, and now york city agar
what are the selective agars for Neisseria gonorrhoeae
35 in 3-5% CO2
Incubation for neisseria spp
72 hours
how many hours should you monitor the incubation period for neisseria spp?
Neisseria gonorrhoeae
Colony Morphology: Small, gray to tan, translucent, and raised colonies after 24–48 hours.
Neisseria gonorrhoeae
Oxidase Test: Positive
1% dimethyl-p-phenylenediamine dihydrochloride andTetramethyl-p-phenylenediamine dihydrochloride
Reagents for neisseria gonorrhoeae
Purple color within 10 seconds
Positive result for Neisseria gonorhoeae
Neisseria gonorrhoeae
Carbohydrate Utilization Test: Fermenter
Medium: Cystine Trypticase Agar (CTA)
pH Indicator: Phenol red
Positive Result: Acid production indicated by yellow color
Fermentation Pattern:
N. gonorrhoeae ferments glucose only
Neisseria meningitidis
Exclusively found in humans
Can exist as a commensal organism in the nasopharynx, but may become invasive
Major cause of:
Endemic and epidemic meningitis
Meningococcemia
Neisseria meningitidis
Rapid-onset, severe infection presenting as:
Meningitis
Sepsis without meningitis
Mortality rate: Up to 25% even with treatment
Petechial rash
Small pinpoint hemorrhagic spots
Purpura
Hemorrhaging into skin or mucous membranes forming bruises
Neisseria meningitidis
Severe cases may lead to:
Disseminated Intravascular Coagulation (DIC)
Septic shock
Adrenal hemorrhage (Waterhouse-Friderichsen Syndrome)
Neisseria Meningitidis
Drug of choice: Third-generation cephalosporins (e.g., ceftriaxone, cefotaxime)
Chemoprophylaxis for close contacts:
Rifampin or ciprofloxacin
Azithromycin (alternative in areas with ciprofloxacin resistance)
Moraxella catarrhalis
Belongs to the family Moraxellaceae (includes Moraxella, Acinetobacter, Psychrobacter)
Found only in humans
Commensal of the upper respiratory tract
Opportunistic pathogen, especially in children and the elderly
Moraxella catarrhalis
Third most common cause of:
Acute otitis media
Sinusitis in children
Also associated with:
Bronchitis and pneumonia in elderly and immunocompromised patients
Moraxella catarrhalis
Gram stain: Gram-negative diplococci, often intracellular
Colony morphology: Smooth, opaque, gray to white colonies
Hockey puck appearance:colonies remain intact when pushed across agar surface with a loop
Older colonies may develop a wagon wheel appearance
Neisseria
Gram stain: Kidney/coffee bean–shaped diplococci
Oxygen requirement: Obligate aerobe
Capnophilic: Yes
Motility: Non-motile
Pyogenic: Yes
Catalase: Positive
Oxidase: Positive
Moraxella catarrhalis
Gram stain: Kidney/coffee bean–shaped diplococci
Oxygen requirement: Obligate aerobe
Capnophilic: Yes
Motility: Non-motile
Pyogenic: No
Catalase: Positive
Oxidase: Positive
Special Tests: DNAse +, Butyrate esterase +, Non-fermenter of carbohydrates
Acinetobacter
Gram stain: Short coccobacilli
Oxygen requirement: Obligate aerobe
Capnophilic: Not necessarily
Motility: Non-motile
Pyogenic: Yes
Catalase: Positive
Oxidase: Negative
Kingella
Gram stain: Bacilli
Oxygen requirement: Obligate aerobe
Capnophilic: Yes
Motility: Non-motile
Pyogenic: Yes
Catalase: Negative
Oxidase: Positive
Tests: Nitrate reduction and indole tests used
N. gonorrhoeae
Catalase: +
Oxidase: +
Superoxol: Positive
Carbohydrate Utilization: Glucose only
ONPG Test: Negative
Neufeld Quellung: Negative
N. meningitidis
Catalase: +
Oxidase: +
Superoxol: Weakly + / mostly –
Carbohydrate Utilization: Glucose & maltose
ONPG Test: Negative
Neufeld Quellung: Positive
N. lactamica
Catalase: +
Oxidase: +
Superoxol: Negative
Carbohydrate Utilization: Glucose, maltose, lactose
ONPG Test: Positive
Neufeld Quellung: Negative
N. sicca
Catalase: +
Oxidase: +
Superoxol: Negative
Carbohydrate Utilization: Glucose, maltose, sucrose, fructose
ONPG Test: Positive
Neufeld Quellung: Negative
N. flavescens
Catalase: +
Oxidase: +
Superoxol: Negative
Carbohydrate Utilization: Non-fermenter
ONPG Test: Negative
Neufeld Quellung: Negative
Moraxella catarrhalis
Catalase: +
Oxidase: +
Superoxol: Negative
Carbohydrate Utilization: Non-fermenter
ONPG Test: Negative
Neufeld Quellung: Negative