Gram negative coci

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