gram negative cocci

- Neisseriaceae
- Moraxellaceae
- Veillonellaceae

3 Families of Bacteria Represents Gram-Negative Cocci

- Eikenella spp.
- Kingella spp.
- Acinetobacter spp.
- Simonsiella spp.
- Alysiella spp.

Gram-Negative Bacilli

Neisseria spp.

gram negative cocci

N. gonorrhoeae
N. meningitidis
N. lactamica
N. sicca
N. flavescens
N. elongata (bacilli)
N. polysaccharea
N. weaveri
N. subflava
N. cinerea

genus under Neisseriaceae

M. catarrhalis
M. mucosa

genus under Moraxellaceae

V. parvula

genus under Veillonellaceae

➔ Gram negative bean-shaped diplococci

➔ Obligate aerobe
➔ Non-motile

➔ Oxidase positive

➔ Catalase positive

➔ Pyogenic
➔ Capnophilic

key characteristics of Neisseria spp.

Neisseria gonorrhoeae
Neisseria meningitidis

2 significant pathogen members of Neisseria spp.

● Neisseria bacilliformis
● Neisseria elongata (bacilli)
● Neisseria flavescens (chromogenic; has a yellow pigmentation)
● Neisseria lactamica
● Neisseria sicca
● Neisseria weaveri
● Moraxella catarrhalis
● Veillonella parvula

normal flora of oral cavity

Neisseria gonorrhoeae
Neisseria meningitidis
Moraxella catarrhalis
Veillonella parvula

diseases caused by gram negative cocci

N. gonorrhoeae

transmitted sexually but may also be transmitted from mother to newborn

2-7 days

how long does N. gonorrhoeae to manifest signs and symptoms

genital area

Gonorrhoea is localizing in the

purulent discharge

gonorrhoeae manifests infection through

salpingitis

inflammation of fallopian tube

➔ Fitz-Hugh-Curtis Syndrome
➔ Septicemia
➔ Gonococcal arthritis

Disseminated Gonorrhea

Ophthalmia neonatorum

eye infection (from the mother to baby via normal
delivery) and may lead to blindness

Gonorrhoea

infection caused by N. gonorrhoeae

urethra

through sexual contact

endocervix

- through sexual contact
- site of infection in females

anal canal

through anal sex

pharynx

through oral sex

conjunctiva

from mother to baby

50% after single exposure

Risk of infection for females

Asymptomatic

Frequency of
symptoms for females

Genital infection's primary site is
cervix (cervicitis) but vagina,
urethra, and rectum can be
colonized.

Dysuria, lower abdominal
pain

Symptoms for females

salpingitis,
tubo-ovarian abscesses,
pelvic inflammatory disease
(PID), sterility, ectopic
pregnancy

Complications for females

Septicemia, infection of skin
and joints (1-3%),
Fitz-Hugh-Curtis Syndrome

Disseminated
infections for females

20% after single exposure

Risk of infection for males

Most initially symptomatic
(95% acute)

Frequency of
symptoms for males

Genital infection is generally
restricted to urethra
(urethritis) with purulent
discharge and dysuria
(burning sensation)

Symptoms for males

Rare complications may
include epididymitis,
prostatitis, and periurethral
abscesses

Complications for males

Very rare

Disseminated
infections for males

pilin

protein part of pili that mediates the firm attachment to non-ciliated human cells such as epithelium of vagina, fallopian tube, and buccal cavity

- por protein (protein I)
- opa protein (protein II)
- rmp protein (protein III)

Other proteins of pili

por protein

also known as porin protein or protein I

por protein

promotes intracellular survival by
preventing phagolysosome fusions in neutrophils

opa protein

also known as opacity protein or protien II

opa protein

mediates firm attachment to the eukaryotic cells

rmp protein

also known as reduction-modifiable protein or protein III

rmp protein

protects other surface antigen such as
protein I and lipooligosaccharide (LOS)

➢ Transferrin-binding proteins

➢ Lactoferrin-binding protein

➢ Hemoglobin-binding proteins

Different types of binding proteins for source of iron

➢ Pili
➢ Lipooligosaccharide (LOS)
➢ IgA1 protease
➢ 𝛃-lactamase

virulence factors of pili

Lipooligosaccharide (LOS)

responsible for fever production

IgA1 protease

destroys immunoglobulin A

𝛃-lactamase

responsible for resistance to 𝛃-lactam antibiotics

N. meningitidis

transmitted via airborne (cough or sneeze)
and is a normal inhabitant of nasopharynx

1. Endemic meningitis
2. Epidemic meningitis
3. Meningococcemia

4. Pneumonia
5. Purulent arthritis
6. Endophthalmitis

Diseases caused by Neisseria meningitidis

Meningococcemia

also known as Waterhouse-Friderichsen Syndrome

Meningococcemia

presence of N. meningitidis in the blood

1-10 days

incubation period of Meningococcemia

➔ Frontal headache
➔ Stiff neck (nuchal rigidity)
➔ Confusion
➔ Photophobia

clinical manifestations of meningitis

menactra

preventive measure for meningitis

➢ Serotype A
➢ Serotype B
➢ Serotype C
➢ Serotype Y

➢ Serotype W135

COMMON SEROLOGICAL TYPES AND DISEASES OF
N. meningitidis

M. catarrhalis

normal flora in the upper respiratory tract

V. parvula

normal flora in the oral cavity

1. Otitis media
2. Maxillary sinusitis
3. Bronchopulmonary infection
4. Endocarditis
5. Meningitis
6. Bacterial tracheitis

diseases caused by M. catarrhalis

1. Periodontitis
2. Dental caries

diseases caused by V. parvula

cavity

Dental caries

Periodontitis

inflammation of gums

cervix

genital primary site of infection in females

urethra

genital primary site of infection in males

obligate anaerobe

type of gas requirement of V. parvula

small, translucent, opaque

colony appearance of V. parvula

positive

reaction of V. parvula in catalase test

positive

reaction of V. parvula nitrate reduction test

brick red

reaction of V. parvula in fluoroscence test

negative

reaction of V. parvula in urease test

resistant

V. parvula in Vancomycin

susceptible

V. parvula in Kanamycin

susceptible

V. parvula in Colistin

Neisseria gonorhoeae

IN GRAM STAIN:

specimen is non-sterile

Transgrow
JEMBEC system

what medium is used to preserve N. gonorrhoeae?

genital specimen
extragenital specimen

types of specimen for the isolation of N. gonorrhoeae

- highy diagnostic
- gram negative diplococci intracellular or extracellular
- many pus cells

gram stain of genital specimen

Neisseria meningitidis

IN GRAM STAIN:

specimen is sterile

Neisseria meningitidis

always significant in any specimen isolated

Cerebrospinal fluid

type of specimen for the isolation of N. meningitidis

Neisseria meningitidis

grows on CAP only

Neisseria gonorrhoeae

grows on selective CAP only

vancomycin, colistin, nystatin, trimethoprim, lincomycin

inhibitory substances of GC Lect medium

5-10% CO2

CO2 component of Modified Thayer Martin

Small, gray to tan, translucent and raised

colony appearance of N. gonorrhoeae on CAP

Medium, gray, convex, mucoid

colony appearance of N. meningitidis on CAP

Small, gray-white with yellow halo, translucent, slightly butyrous

colony appearance of N. lactamica on CAP

Large, gray-white opaque, wrinkled, dry, adherent (resembles bread crumb)

colony appearance of N. sica on CAP

Golden yellow

colony appearance of N. flavescens on CAP

Small, opaque, gray-white with wavy slides / borders
hocky puck appearance

colony appearance of M. catarrhalis on CAP

FALSE

TRUE OR FALSE

All gram negative cocci are NEGATIVE in Oxidase test except V. parvula

blue to purple to black

positive color of oxidase test

V. parvula

the only gram negative cocci negative in oxidase test

tetramethyl-p-phenylenediamine dihydrochloride

active chemical component of oxidase test

carbohydrate utilization test

reference method for identifying Neisseria spp. and M. catarrhalis

20% / 30% hydrogen peroxide

reagent used in superoxol test

30% hydrogen peroxide

most commonly used reagent in superoxol test

vigorous bubble formation / effervescence

positive reaction of superoxol test

Neisseria gonorrhoeae

gram negative cocci that is positive in superoxol test

yellow

positive reaction in carbohydrate utilization test

carbohydrate is utilized

in carbohydrate utilization test, yellow color indicates that?

Cystine Trypticase Agar

medium used in carbohydrate utilization test