GRAM-NEGATIVE COCCI

Neisseria gonorrhoeae

not part of the normal human flora

found on mucous membranes of genitalia, anorectal area, oropharynx, or conjunctiva at time of infection

leading cause of sexually transmitted disease

Person-to-person spread

sexual contact

infected mother to newborn during birth

mode of transmission of Neisseria gonorrhoeae

Pili

mediate the exchange of genetic material between strains

attachment to human mucosal cell surface

invasion of host cells

survival through the inhibition of phagocytosis

Opa

facilitates adherence to phagocytic and epithelial cells

RMP

blocks the bactericidal effect of host IgG

Outer membrane Porin (PorB)

provides protection from the host’s immune response

Lipooligosaccharide

endotoxin

Outer membrane proteins I-III

can cause disease

Pili

Protein II

Outer membrane Porin

Capsule

Lipooligosaccharide

Outer membrane proteins I-III

Virulence factors of Neisseria gonorrhoeae

Males

Will cause acute purulent urethritis, Prostatitis, and Epididymitis

Females

Neisseria gonorrhoeae can cause acute purulent urethritis, acute cervicitis, and can lead to pelvic inflammatory disease

Pelvic inflammatory disease

can cause endometritis, salpingitis, and oophoritis

Sterility

Ectopic pregnancy

Abscesses

Peritonitis

Perihepatitis

complications of PID

Sterility

most commonly caused by scarring of the fallopian tubes, which occludes the lumen and prevents sperms from reaching the ovulated egg

Ectopic pregnancy

fetus developing at a site other than the uterus

most common site: fallopian tubes

Peritonitis

infection of peritoneal cavity

Perihepatitis

Fitz-High-Curtis syndrome

Infection of the capsule that surrounds the liver

Symptom: right upper quadrant pain and tenderness

Pharyngitis

Anorectal infections

Conjunctivitis

Ophthalmia neonatorum of newborns

Bacteremia

Arthritis

Metastatic infection

Localized infections of PID

N. gonorrhea and meningitidis

are sensitive to sodium polyanethol sulfonate

Charcoal (Ames medium)

added to transport medium to inhibit toxic fatty acids present in the fibers

Vancomycin

inhibits gram-positive bacteria

Colistin

inhibit gram-negative bacilli

Modified Thayer-Martin

inhibit swarming Proteus spp.

Martin Lewis

same with MTM except that nystatin is replaced with anisomycin and the concentration of vancomycin is increased

Nystatin

inhibit yeast

GC-LECT agar

contains antimicrobials to inhibit bacteria found in oropharyngeal specimens

New York City (NYC)

contain lysed horse blood, horse plasma, yeast dialysate, and the same antibiotics as MTM

35 to 37 degrees celcius for 72 hours in a CO2 enriched, humid atmosphere

incubation conditions and duration

Small

Grayish white

Convex

Translucent

Shiny colonies with either smooth or irregular margins

colonial appearance of Neisseria gonorrhea

Neisseria gonorrhea

identify the organism:

Facultative anaerobe

Oxidase positive

DNase negative

ferments glucose only

has small, grayish white, translucent shiny colonies

Penicillin

Tetracycline

Fluoroquinolones

N. gonorrhoeae is resistant to?

extended spectrum cephalosporins

treatment for N.gonorrhoeae

Antimicrobial susceptibility

performed if symptoms persist after treatment

Neisseria meningitidis

Identify the organism:

Facultative anaerobe

Oxidase positive

Ferments glucose and maltose

DNase negative

has medium, smooth, moist, gray to white, may be greenish cast in agar underneath colonies

N. meningitidis

colonizes oropharyngeal and nasopharyngeal mucous membranes of humans

leading cause of fatal bacterial menigitis

Person-to-person spread by contaminated respiratory droplets, usually in settings of close contact

Mode of transmission of N. meningitidis

Capsule

Antiphagocytic; 9 serogroupsE

Endotoxin (LPS)

causes blood vessel destruction and sepsis

seen on the skin as tiny, round, petechiae

Petechiae

red dots of hemorrhage

IgA protease

degrades membrane-associated IgA, increasing the host’s susceptibility to invasion

Meningococcemia

intravascular multiplication of N. menigitidis

Symptoms: abrupt onset of spiking fevers, chills, arthralgia, and muscle pains

can lead to meningitis and/or fulminant meningococcemia

Fulminant meningococcemia

Waterhouse-Friderichsen syndrome

septic shock

bilateral hemorrhage into the adrenal glands causing adrenal insufficiency

can lead to disseminated intravascular coagulation and coma

death can occur rapidly

Meningitis

usually striking infants < 1 year of age

Neonates

bulging open anterior fontanelle

Slightly odler infants

stiff neck; positive Kernig’s and Brudzinski’s signs

Penicillin G

drug of choice

Other Neisseria spp.

normal human flora of the upper respiratory tract

often considered as saprophytic Neisseria

N. animaloris

some strains exhibit yellow to tan pigment; odor resembles popcorn

N. cinerea

small, greyish white; translucent; slightly granular

N. flavescens

medium, yellow, opaque, smooth

N. lactamica

small, nonpigmented or yellowish, smooth, transparent

N. mucosa

large, grayish, white to light yellow, translucent; mucoid because of capsule

N. polysaccharea

small, grayish white to light yellow, translucent, raised

N. sicca

large, nonpigmented, wrinkled, coarse and dry, adherent

N. subflava

medium, greenish yellow to yellow, smooth, entire edge

M. catarrhalis

normal human flora of upper respiratory tract

occasionally colonizes female genital tract

Moraxella catarrhalis

identify the organism:

Oxidase positive

does not utilize carbohydrates

reduces nitrate to nitrite

produces DNase

has large, nonpigmented or gray, opaque, smooth; Friable “hockey puck” consistency